fix(chat): remove duplicate drain_done declaration after rebase

When the HTTP client disconnects, Starlette throws GeneratorExit into the
drain loop generator. The old code called executor.shutdown(wait=False) with
no completion handling, leaving the assistant DB message as the TERMINATED
placeholder forever (regressing test_send_message_disconnect_and_cleanup).

New design:
- drain_done (threading.Event) signals emitters to return immediately instead
  of blocking on queue.put — no retry loops, no daemon threads
- One-time queue drain in the else block releases any in-progress puts so
  workers exit within milliseconds
- Workers self-complete: after run_llm_loop returns, each worker checks
  drain_done.is_set() and, if true, opens its own DB session and calls
  llm_loop_completion_handle directly

Unit test updated to reflect the async self-completion semantics: the test
blocks the worker inside run_llm_loop until gen.close() sets drain_done,
then waits for completion_called inside the patch context (while mocks are
still active) to avoid calling the real get_session_with_current_tenant.

.github/workflows/nightly-llm-provider-chat.yml

@@ -35,6 +35,7 @@ jobs:
     needs: [provider-chat-test]
     if: failure() && github.event_name == 'schedule'
     runs-on: ubuntu-slim
+    environment: ci-protected
     timeout-minutes: 5
     steps:
       - name: Checkout

.github/workflows/post-merge-beta-cherry-pick.yml

@@ -183,6 +183,7 @@ jobs:
       - cherry-pick-to-latest-release
     if: needs.resolve-cherry-pick-request.outputs.should_cherrypick == 'true' && needs.resolve-cherry-pick-request.result == 'success' && needs.cherry-pick-to-latest-release.result == 'success'
     runs-on: ubuntu-slim
+    environment: ci-protected
     timeout-minutes: 10
     steps:
       - name: Checkout
@@ -232,6 +233,7 @@ jobs:
       - cherry-pick-to-latest-release
     if: always() && needs.resolve-cherry-pick-request.outputs.should_cherrypick == 'true' && (needs.resolve-cherry-pick-request.result == 'failure' || needs.cherry-pick-to-latest-release.result == 'failure')
     runs-on: ubuntu-slim
+    environment: ci-protected
     timeout-minutes: 10
     steps:
       - name: Checkout

.github/workflows/pr-desktop-build.yml

@@ -63,7 +63,7 @@ jobs:
           targets: ${{ matrix.target }}
 
       - name: Cache Cargo registry and build
-        uses: actions/cache@cdf6c1fa76f9f475f3d7449005a359c84ca0f306 # zizmor: ignore[cache-poisoning]
+        uses: actions/cache@668228422ae6a00e4ad889ee87cd7109ec5666a7 # zizmor: ignore[cache-poisoning]
         with:
           path: |
             ~/.cargo/bin/

.github/workflows/pr-playwright-tests.yml

@@ -284,7 +284,7 @@ jobs:
 
       - name: Cache playwright cache
         # zizmor: ignore[cache-poisoning] ephemeral runners; no release artifacts
-        uses: runs-on/cache@50350ad4242587b6c8c2baa2e740b1bc11285ff4 # ratchet:runs-on/cache@v4
+        uses: runs-on/cache@a5f51d6f3fece787d03b7b4e981c82538a0654ed # ratchet:runs-on/cache@v4
         with:
           path: ~/.cache/ms-playwright
           key: ${{ runner.os }}-playwright-npm-${{ hashFiles('web/package-lock.json') }}
@@ -626,7 +626,7 @@ jobs:
 
       - name: Cache playwright cache
         # zizmor: ignore[cache-poisoning] ephemeral runners; no release artifacts
-        uses: runs-on/cache@50350ad4242587b6c8c2baa2e740b1bc11285ff4 # ratchet:runs-on/cache@v4
+        uses: runs-on/cache@a5f51d6f3fece787d03b7b4e981c82538a0654ed # ratchet:runs-on/cache@v4
         with:
           path: ~/.cache/ms-playwright
           key: ${{ runner.os }}-playwright-npm-${{ hashFiles('web/package-lock.json') }}

.github/workflows/pr-python-checks.yml

@@ -56,7 +56,7 @@ jobs:
 
       - name: Cache mypy cache
         if: ${{ vars.DISABLE_MYPY_CACHE != 'true' }}
-        uses: runs-on/cache@50350ad4242587b6c8c2baa2e740b1bc11285ff4 # ratchet:runs-on/cache@v4
+        uses: runs-on/cache@a5f51d6f3fece787d03b7b4e981c82538a0654ed # ratchet:runs-on/cache@v4
         with:
           path: .mypy_cache
           key: mypy-${{ runner.os }}-${{ github.base_ref || github.event.merge_group.base_ref || 'main' }}-${{ hashFiles('**/*.py', '**/*.pyi', 'pyproject.toml') }}

.github/workflows/pr-python-model-tests.yml

@@ -31,6 +31,7 @@ jobs:
       - runner=4cpu-linux-arm64
       - "run-id=${{ github.run_id }}-model-check"
       - "extras=ecr-cache"
+    environment: ci-protected
     timeout-minutes: 45
 
     env:

.github/workflows/preview.yml

@@ -15,6 +15,7 @@ permissions:
 jobs:
   Deploy-Preview:
     runs-on: ubuntu-latest
+    environment: ci-protected
     timeout-minutes: 30
     steps:
       - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd

.github/workflows/storybook-deploy.yml

@@ -25,6 +25,7 @@ permissions:
 jobs:
   Deploy-Storybook:
     runs-on: ubuntu-latest
+    environment: ci-protected
     timeout-minutes: 30
     steps:
       - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # ratchet:actions/checkout@v4
@@ -54,6 +55,7 @@ jobs:
     needs: Deploy-Storybook
     if: always() && needs.Deploy-Storybook.result == 'failure'
     runs-on: ubuntu-latest
+    environment: ci-protected
     timeout-minutes: 10
     steps:
       - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # ratchet:actions/checkout@v4

.github/workflows/sync_foss.yml

@@ -9,6 +9,7 @@ on:
 jobs:
   sync-foss:
     runs-on: ubuntu-latest
+    environment: ci-protected
     timeout-minutes: 45
     permissions:
       contents: read

.github/workflows/tag-nightly.yml

@@ -11,6 +11,7 @@ permissions:
 jobs:
   create-and-push-tag:
     runs-on: ubuntu-slim
+    environment: ci-protected
     timeout-minutes: 45
 
     steps:

backend/onyx/chat/chat_state.py

@@ -1,19 +1,8 @@
 import threading
-import time
-from collections.abc import Callable
-from collections.abc import Generator
-from queue import Empty
 
 from onyx.chat.citation_processor import CitationMapping
-from onyx.chat.emitter import Emitter
 from onyx.context.search.models import SearchDoc
-from onyx.server.query_and_chat.placement import Placement
-from onyx.server.query_and_chat.streaming_models import OverallStop
-from onyx.server.query_and_chat.streaming_models import Packet
-from onyx.server.query_and_chat.streaming_models import PacketException
 from onyx.tools.models import ToolCallInfo
-from onyx.utils.threadpool_concurrency import run_in_background
-from onyx.utils.threadpool_concurrency import wait_on_background
 
 # Type alias for search doc deduplication key
 # Simple key: just document_id (str)
@@ -159,114 +148,3 @@ class ChatStateContainer:
         """Thread-safe getter for emitted citations (returns a copy)."""
         with self._lock:
             return self._emitted_citations.copy()
-
-
-def run_chat_loop_with_state_containers(
-    chat_loop_func: Callable[[Emitter, ChatStateContainer], None],
-    completion_callback: Callable[[ChatStateContainer], None],
-    is_connected: Callable[[], bool],
-    emitter: Emitter,
-    state_container: ChatStateContainer,
-) -> Generator[Packet, None]:
-    """
-    Explicit wrapper function that runs a function in a background thread
-    with event streaming capabilities.
-
-    The wrapped function should accept emitter as first arg and use it to emit
-    Packet objects. This wrapper polls every 300ms to check if stop signal is set.
-
-    Args:
-        func: The function to wrap (should accept emitter and state_container as first and second args)
-        completion_callback: Callback function to call when the function completes
-        emitter: Emitter instance for sending packets
-        state_container: ChatStateContainer instance for accumulating state
-        is_connected: Callable that returns False when stop signal is set
-
-    Usage:
-        packets = run_chat_loop_with_state_containers(
-            my_func,
-            completion_callback=completion_callback,
-            emitter=emitter,
-            state_container=state_container,
-            is_connected=check_func,
-        )
-        for packet in packets:
-            # Process packets
-            pass
-    """
-
-    def run_with_exception_capture() -> None:
-        try:
-            chat_loop_func(emitter, state_container)
-        except Exception as e:
-            # If execution fails, emit an exception packet
-            emitter.emit(
-                Packet(
-                    placement=Placement(turn_index=0),
-                    obj=PacketException(type="error", exception=e),
-                )
-            )
-
-    # Run the function in a background thread
-    thread = run_in_background(run_with_exception_capture)
-
-    pkt: Packet | None = None
-    last_turn_index = 0  # Track the highest turn_index seen for stop packet
-    last_cancel_check = time.monotonic()
-    cancel_check_interval = 0.3  # Check for cancellation every 300ms
-    try:
-        while True:
-            # Poll queue with 300ms timeout for natural stop signal checking
-            # the 300ms timeout is to avoid busy-waiting and to allow the stop signal to be checked regularly
-            try:
-                pkt = emitter.bus.get(timeout=0.3)
-            except Empty:
-                if not is_connected():
-                    # Stop signal detected
-                    yield Packet(
-                        placement=Placement(turn_index=last_turn_index + 1),
-                        obj=OverallStop(type="stop", stop_reason="user_cancelled"),
-                    )
-                    break
-                last_cancel_check = time.monotonic()
-                continue
-
-            if pkt is not None:
-                # Track the highest turn_index for the stop packet
-                if pkt.placement and pkt.placement.turn_index > last_turn_index:
-                    last_turn_index = pkt.placement.turn_index
-
-                if isinstance(pkt.obj, OverallStop):
-                    yield pkt
-                    break
-                elif isinstance(pkt.obj, PacketException):
-                    raise pkt.obj.exception
-                else:
-                    yield pkt
-
-                # Check for cancellation periodically even when packets are flowing
-                # This ensures stop signal is checked during active streaming
-                current_time = time.monotonic()
-                if current_time - last_cancel_check >= cancel_check_interval:
-                    if not is_connected():
-                        # Stop signal detected during streaming
-                        yield Packet(
-                            placement=Placement(turn_index=last_turn_index + 1),
-                            obj=OverallStop(type="stop", stop_reason="user_cancelled"),
-                        )
-                        break
-                    last_cancel_check = current_time
-    finally:
-        # Wait for thread to complete on normal exit to propagate exceptions and ensure cleanup.
-        # Skip waiting if user disconnected to exit quickly.
-        if is_connected():
-            wait_on_background(thread)
-        try:
-            completion_callback(state_container)
-        except Exception as e:
-            emitter.emit(
-                Packet(
-                    placement=Placement(turn_index=last_turn_index + 1),
-                    obj=PacketException(type="error", exception=e),
-                )
-            )

backend/onyx/chat/emitter.py

@@ -1,19 +1,40 @@
+import threading
 from queue import Queue
 
+from onyx.server.query_and_chat.placement import Placement
 from onyx.server.query_and_chat.streaming_models import Packet
 
 
 class Emitter:
-    """Use this inside tools to emit arbitrary UI progress."""
+    """Routes packets from LLM/tool execution to the ``_run_models`` drain loop.
 
-    def __init__(self, bus: Queue):
-        self.bus = bus
+    Tags every packet with ``model_index`` and places it on ``merged_queue``
+    as a ``(model_idx, packet)`` tuple for ordered consumption downstream.
+
+    Args:
+        merged_queue: Shared queue owned by ``_run_models``.
+        model_idx: Index embedded in packet placements (``0`` for N=1 runs).
+        drain_done: Optional event set by ``_run_models`` when the drain loop
+            exits early (e.g. HTTP disconnect). When set, ``emit`` returns
+            immediately so worker threads can exit fast.
+    """
+
+    def __init__(
+        self,
+        merged_queue: Queue[tuple[int, Packet | Exception | object]],
+        model_idx: int = 0,
+        drain_done: threading.Event | None = None,
+    ) -> None:
+        self._model_idx = model_idx
+        self._merged_queue = merged_queue
+        self._drain_done = drain_done
 
     def emit(self, packet: Packet) -> None:
-        self.bus.put(packet)  # Thread-safe
-
-
-def get_default_emitter() -> Emitter:
-    bus: Queue[Packet] = Queue()
-    emitter = Emitter(bus)
-    return emitter
+        if self._drain_done is not None and self._drain_done.is_set():
+            return
+        base = packet.placement or Placement(turn_index=0)
+        tagged = Packet(
+            placement=base.model_copy(update={"model_index": self._model_idx}),
+            obj=packet.obj,
+        )
+        self._merged_queue.put((self._model_idx, tagged))

backend/onyx/configs/app_configs.py

@@ -805,6 +805,10 @@ MINI_CHUNK_SIZE = 150
 # This is the number of regular chunks per large chunk
 LARGE_CHUNK_RATIO = 4
 
+# The maximum number of chunks that can be held for 1 document processing batch
+# The purpose of this is to set an upper bound on memory usage
+MAX_CHUNKS_PER_DOC_BATCH = int(os.environ.get("MAX_CHUNKS_PER_DOC_BATCH") or 1000)
+
 # Include the document level metadata in each chunk. If the metadata is too long, then it is thrown out
 # We don't want the metadata to overwhelm the actual contents of the chunk
 SKIP_METADATA_IN_CHUNK = os.environ.get("SKIP_METADATA_IN_CHUNK", "").lower() == "true"

backend/onyx/db/chat.py

@@ -617,6 +617,92 @@ def reserve_message_id(
     return empty_message
 
 
+def reserve_multi_model_message_ids(
+    db_session: Session,
+    chat_session_id: UUID,
+    parent_message_id: int,
+    model_display_names: list[str],
+) -> list[ChatMessage]:
+    """Reserve N assistant message placeholders for multi-model parallel streaming.
+
+    All messages share the same parent (the user message). The parent's
+    latest_child_message_id points to the LAST reserved message so that the
+    default history-chain walker picks it up.
+    """
+    reserved: list[ChatMessage] = []
+    for display_name in model_display_names:
+        msg = ChatMessage(
+            chat_session_id=chat_session_id,
+            parent_message_id=parent_message_id,
+            latest_child_message_id=None,
+            message="Response was terminated prior to completion, try regenerating.",
+            token_count=15,  # placeholder; updated on completion by llm_loop_completion_handle
+            message_type=MessageType.ASSISTANT,
+            model_display_name=display_name,
+        )
+        db_session.add(msg)
+        reserved.append(msg)
+
+    # Flush to assign IDs without committing yet
+    db_session.flush()
+
+    # Point parent's latest_child to the last reserved message
+    parent = (
+        db_session.query(ChatMessage)
+        .filter(ChatMessage.id == parent_message_id)
+        .first()
+    )
+    if parent:
+        parent.latest_child_message_id = reserved[-1].id
+
+    db_session.commit()
+    return reserved
+
+
+def set_preferred_response(
+    db_session: Session,
+    user_message_id: int,
+    preferred_assistant_message_id: int,
+) -> None:
+    """Mark one assistant response as the user's preferred choice in a multi-model turn.
+
+    Also advances ``latest_child_message_id`` so the preferred response becomes
+    the active branch for any subsequent messages in the conversation.
+
+    Args:
+        db_session: Active database session.
+        user_message_id: Primary key of the ``USER``-type ``ChatMessage`` whose
+            preferred response is being set.
+        preferred_assistant_message_id: Primary key of the ``ASSISTANT``-type
+            ``ChatMessage`` to prefer. Must be a direct child of ``user_message_id``.
+
+    Raises:
+        ValueError: If either message is not found, if ``user_message_id`` does not
+            refer to a USER message, or if the assistant message is not a direct child
+            of the user message.
+    """
+    user_msg = db_session.get(ChatMessage, user_message_id)
+    if user_msg is None:
+        raise ValueError(f"User message {user_message_id} not found")
+    if user_msg.message_type != MessageType.USER:
+        raise ValueError(f"Message {user_message_id} is not a user message")
+
+    assistant_msg = db_session.get(ChatMessage, preferred_assistant_message_id)
+    if assistant_msg is None:
+        raise ValueError(
+            f"Assistant message {preferred_assistant_message_id} not found"
+        )
+    if assistant_msg.parent_message_id != user_message_id:
+        raise ValueError(
+            f"Assistant message {preferred_assistant_message_id} is not a child "
+            f"of user message {user_message_id}"
+        )
+
+    user_msg.preferred_response_id = preferred_assistant_message_id
+    user_msg.latest_child_message_id = preferred_assistant_message_id
+    db_session.commit()
+
+
 def create_new_chat_message(
     chat_session_id: UUID,
     parent_message: ChatMessage,
@@ -839,6 +925,8 @@ def translate_db_message_to_chat_message_detail(
         error=chat_message.error,
         current_feedback=current_feedback,
         processing_duration_seconds=chat_message.processing_duration_seconds,
+        preferred_response_id=chat_message.preferred_response_id,
+        model_display_name=chat_message.model_display_name,
     )
 
     return chat_msg_detail

backend/onyx/document_index/opensearch/opensearch_document_index.py

@@ -6,6 +6,7 @@ import httpx
 from opensearchpy import NotFoundError
 
 from onyx.access.models import DocumentAccess
+from onyx.configs.app_configs import MAX_CHUNKS_PER_DOC_BATCH
 from onyx.configs.app_configs import VERIFY_CREATE_OPENSEARCH_INDEX_ON_INIT_MT
 from onyx.configs.chat_configs import NUM_RETURNED_HITS
 from onyx.configs.chat_configs import TITLE_CONTENT_RATIO
@@ -738,6 +739,9 @@ class OpenSearchDocumentIndex(DocumentIndex):
                     _flush_chunks(current_chunks)
                 current_doc_id = doc_id
                 current_chunks = [chunk]
+            elif len(current_chunks) >= MAX_CHUNKS_PER_DOC_BATCH:
+                _flush_chunks(current_chunks)
+                current_chunks = [chunk]
             else:
                 current_chunks.append(chunk)
 

backend/onyx/document_index/vespa/vespa_document_index.py

@@ -10,6 +10,7 @@ import httpx
 from pydantic import BaseModel
 from retry import retry
 
+from onyx.configs.app_configs import MAX_CHUNKS_PER_DOC_BATCH
 from onyx.configs.app_configs import RECENCY_BIAS_MULTIPLIER
 from onyx.configs.app_configs import RERANK_COUNT
 from onyx.configs.chat_configs import DOC_TIME_DECAY
@@ -427,7 +428,9 @@ class VespaDocumentIndex(DocumentIndex):
                 new_document_id_to_original_document_id,
                 all_cleaned_doc_ids,
             )
-            for chunk_batch in batch_generator(cleaned_chunks, BATCH_SIZE):
+            for chunk_batch in batch_generator(
+                cleaned_chunks, min(BATCH_SIZE, MAX_CHUNKS_PER_DOC_BATCH)
+            ):
                 batch_index_vespa_chunks(
                     chunks=chunk_batch,
                     index_name=self._index_name,

backend/onyx/indexing/adapters/document_indexing_adapter.py

@@ -19,7 +19,8 @@ from onyx.db.document import update_docs_updated_at__no_commit
 from onyx.db.document_set import fetch_document_sets_for_documents
 from onyx.indexing.indexing_pipeline import DocumentBatchPrepareContext
 from onyx.indexing.indexing_pipeline import index_doc_batch_prepare
-from onyx.indexing.models import BuildMetadataAwareChunksResult
+from onyx.indexing.models import ChunkEnrichmentContext
+from onyx.indexing.models import DocAwareChunk
 from onyx.indexing.models import DocMetadataAwareIndexChunk
 from onyx.indexing.models import IndexChunk
 from onyx.indexing.models import UpdatableChunkData
@@ -85,14 +86,21 @@ class DocumentIndexingBatchAdapter:
         ) as transaction:
             yield transaction
 
-    def build_metadata_aware_chunks(
+    def prepare_enrichment(
         self,
-        chunks_with_embeddings: list[IndexChunk],
-        chunk_content_scores: list[float],
-        tenant_id: str,
         context: DocumentBatchPrepareContext,
-    ) -> BuildMetadataAwareChunksResult:
-        """Enrich chunks with access, document sets, boosts, token counts, and hierarchy."""
+        tenant_id: str,
+        chunks: list[DocAwareChunk],
+    ) -> "DocumentChunkEnricher":
+        """Do all DB lookups once and return a per-chunk enricher."""
+        updatable_ids = [doc.id for doc in context.updatable_docs]
+
+        doc_id_to_new_chunk_cnt: dict[str, int] = {
+            doc_id: 0 for doc_id in updatable_ids
+        }
+        for chunk in chunks:
+            if chunk.source_document.id in doc_id_to_new_chunk_cnt:
+                doc_id_to_new_chunk_cnt[chunk.source_document.id] += 1
 
         no_access = DocumentAccess.build(
             user_emails=[],
@@ -102,67 +110,30 @@ class DocumentIndexingBatchAdapter:
             is_public=False,
         )
 
-        updatable_ids = [doc.id for doc in context.updatable_docs]
-
-        doc_id_to_access_info = get_access_for_documents(
-            document_ids=updatable_ids, db_session=self.db_session
-        )
-        doc_id_to_document_set = {
-            document_id: document_sets
-            for document_id, document_sets in fetch_document_sets_for_documents(
+        return DocumentChunkEnricher(
+            doc_id_to_access_info=get_access_for_documents(
                 document_ids=updatable_ids, db_session=self.db_session
-            )
-        }
-
-        doc_id_to_previous_chunk_cnt: dict[str, int] = {
-            document_id: chunk_count
-            for document_id, chunk_count in fetch_chunk_counts_for_documents(
-                document_ids=updatable_ids,
-                db_session=self.db_session,
-            )
-        }
-
-        doc_id_to_new_chunk_cnt: dict[str, int] = {
-            doc_id: 0 for doc_id in updatable_ids
-        }
-        for chunk in chunks_with_embeddings:
-            if chunk.source_document.id in doc_id_to_new_chunk_cnt:
-                doc_id_to_new_chunk_cnt[chunk.source_document.id] += 1
-
-        # Get ancestor hierarchy node IDs for each document
-        doc_id_to_ancestor_ids = self._get_ancestor_ids_for_documents(
-            context.updatable_docs, tenant_id
-        )
-
-        access_aware_chunks = [
-            DocMetadataAwareIndexChunk.from_index_chunk(
-                index_chunk=chunk,
-                access=doc_id_to_access_info.get(chunk.source_document.id, no_access),
-                document_sets=set(
-                    doc_id_to_document_set.get(chunk.source_document.id, [])
-                ),
-                user_project=[],
-                personas=[],
-                boost=(
-                    context.id_to_boost_map[chunk.source_document.id]
-                    if chunk.source_document.id in context.id_to_boost_map
-                    else DEFAULT_BOOST
-                ),
-                tenant_id=tenant_id,
-                aggregated_chunk_boost_factor=chunk_content_scores[chunk_num],
-                ancestor_hierarchy_node_ids=doc_id_to_ancestor_ids[
-                    chunk.source_document.id
-                ],
-            )
-            for chunk_num, chunk in enumerate(chunks_with_embeddings)
-        ]
-
-        return BuildMetadataAwareChunksResult(
-            chunks=access_aware_chunks,
-            doc_id_to_previous_chunk_cnt=doc_id_to_previous_chunk_cnt,
-            doc_id_to_new_chunk_cnt=doc_id_to_new_chunk_cnt,
-            user_file_id_to_raw_text={},
-            user_file_id_to_token_count={},
+            ),
+            doc_id_to_document_set={
+                document_id: document_sets
+                for document_id, document_sets in fetch_document_sets_for_documents(
+                    document_ids=updatable_ids, db_session=self.db_session
+                )
+            },
+            doc_id_to_ancestor_ids=self._get_ancestor_ids_for_documents(
+                context.updatable_docs, tenant_id
+            ),
+            id_to_boost_map=context.id_to_boost_map,
+            doc_id_to_previous_chunk_cnt={
+                document_id: chunk_count
+                for document_id, chunk_count in fetch_chunk_counts_for_documents(
+                    document_ids=updatable_ids,
+                    db_session=self.db_session,
+                )
+            },
+            doc_id_to_new_chunk_cnt=dict(doc_id_to_new_chunk_cnt),
+            no_access=no_access,
+            tenant_id=tenant_id,
         )
 
     def _get_ancestor_ids_for_documents(
@@ -203,7 +174,7 @@ class DocumentIndexingBatchAdapter:
         context: DocumentBatchPrepareContext,
         updatable_chunk_data: list[UpdatableChunkData],
         filtered_documents: list[Document],
-        result: BuildMetadataAwareChunksResult,
+        enrichment: ChunkEnrichmentContext,
     ) -> None:
         """Finalize DB updates, store plaintext, and mark docs as indexed."""
         updatable_ids = [doc.id for doc in context.updatable_docs]
@@ -227,7 +198,7 @@ class DocumentIndexingBatchAdapter:
 
         update_docs_chunk_count__no_commit(
             document_ids=updatable_ids,
-            doc_id_to_chunk_count=result.doc_id_to_new_chunk_cnt,
+            doc_id_to_chunk_count=enrichment.doc_id_to_new_chunk_cnt,
             db_session=self.db_session,
         )
 
@@ -249,3 +220,52 @@ class DocumentIndexingBatchAdapter:
         )
 
         self.db_session.commit()
+
+
+class DocumentChunkEnricher:
+    """Pre-computed metadata for per-chunk enrichment of connector documents."""
+
+    def __init__(
+        self,
+        doc_id_to_access_info: dict[str, DocumentAccess],
+        doc_id_to_document_set: dict[str, list[str]],
+        doc_id_to_ancestor_ids: dict[str, list[int]],
+        id_to_boost_map: dict[str, int],
+        doc_id_to_previous_chunk_cnt: dict[str, int],
+        doc_id_to_new_chunk_cnt: dict[str, int],
+        no_access: DocumentAccess,
+        tenant_id: str,
+    ) -> None:
+        self._doc_id_to_access_info = doc_id_to_access_info
+        self._doc_id_to_document_set = doc_id_to_document_set
+        self._doc_id_to_ancestor_ids = doc_id_to_ancestor_ids
+        self._id_to_boost_map = id_to_boost_map
+        self._no_access = no_access
+        self._tenant_id = tenant_id
+        self.doc_id_to_previous_chunk_cnt = doc_id_to_previous_chunk_cnt
+        self.doc_id_to_new_chunk_cnt = doc_id_to_new_chunk_cnt
+
+    def enrich_chunk(
+        self, chunk: IndexChunk, score: float
+    ) -> DocMetadataAwareIndexChunk:
+        return DocMetadataAwareIndexChunk.from_index_chunk(
+            index_chunk=chunk,
+            access=self._doc_id_to_access_info.get(
+                chunk.source_document.id, self._no_access
+            ),
+            document_sets=set(
+                self._doc_id_to_document_set.get(chunk.source_document.id, [])
+            ),
+            user_project=[],
+            personas=[],
+            boost=(
+                self._id_to_boost_map[chunk.source_document.id]
+                if chunk.source_document.id in self._id_to_boost_map
+                else DEFAULT_BOOST
+            ),
+            tenant_id=self._tenant_id,
+            aggregated_chunk_boost_factor=score,
+            ancestor_hierarchy_node_ids=self._doc_id_to_ancestor_ids[
+                chunk.source_document.id
+            ],
+        )

backend/onyx/indexing/adapters/user_file_indexing_adapter.py

@@ -1,6 +1,9 @@
+from __future__ import annotations
+
 import contextlib
 import datetime
 import time
+from collections import defaultdict
 from collections.abc import Generator
 from uuid import UUID
 
@@ -24,7 +27,8 @@ from onyx.db.user_file import fetch_persona_ids_for_user_files
 from onyx.db.user_file import fetch_user_project_ids_for_user_files
 from onyx.file_store.utils import store_user_file_plaintext
 from onyx.indexing.indexing_pipeline import DocumentBatchPrepareContext
-from onyx.indexing.models import BuildMetadataAwareChunksResult
+from onyx.indexing.models import ChunkEnrichmentContext
+from onyx.indexing.models import DocAwareChunk
 from onyx.indexing.models import DocMetadataAwareIndexChunk
 from onyx.indexing.models import IndexChunk
 from onyx.indexing.models import UpdatableChunkData
@@ -102,13 +106,20 @@ class UserFileIndexingAdapter:
                 f"Failed to acquire locks after {_NUM_LOCK_ATTEMPTS} attempts for user files: {[doc.id for doc in documents]}"
             )
 
-    def build_metadata_aware_chunks(
+    def prepare_enrichment(
         self,
-        chunks_with_embeddings: list[IndexChunk],
-        chunk_content_scores: list[float],
-        tenant_id: str,
         context: DocumentBatchPrepareContext,
-    ) -> BuildMetadataAwareChunksResult:
+        tenant_id: str,
+        chunks: list[DocAwareChunk],
+    ) -> UserFileChunkEnricher:
+        """Do all DB lookups and pre-compute file metadata from chunks."""
+        updatable_ids = [doc.id for doc in context.updatable_docs]
+
+        doc_id_to_new_chunk_cnt: dict[str, int] = defaultdict(int)
+        content_by_file: dict[str, list[str]] = defaultdict(list)
+        for chunk in chunks:
+            doc_id_to_new_chunk_cnt[chunk.source_document.id] += 1
+            content_by_file[chunk.source_document.id].append(chunk.content)
 
         no_access = DocumentAccess.build(
             user_emails=[],
@@ -118,7 +129,6 @@ class UserFileIndexingAdapter:
             is_public=False,
         )
 
-        updatable_ids = [doc.id for doc in context.updatable_docs]
         user_file_id_to_project_ids = fetch_user_project_ids_for_user_files(
             user_file_ids=updatable_ids,
             db_session=self.db_session,
@@ -139,17 +149,6 @@ class UserFileIndexingAdapter:
             )
         }
 
-        user_file_id_to_new_chunk_cnt: dict[str, int] = {
-            user_file_id: len(
-                [
-                    chunk
-                    for chunk in chunks_with_embeddings
-                    if chunk.source_document.id == user_file_id
-                ]
-            )
-            for user_file_id in updatable_ids
-        }
-
         # Initialize tokenizer used for token count calculation
         try:
             llm = get_default_llm()
@@ -164,15 +163,9 @@ class UserFileIndexingAdapter:
         user_file_id_to_raw_text: dict[str, str] = {}
         user_file_id_to_token_count: dict[str, int | None] = {}
         for user_file_id in updatable_ids:
-            user_file_chunks = [
-                chunk
-                for chunk in chunks_with_embeddings
-                if chunk.source_document.id == user_file_id
-            ]
-            if user_file_chunks:
-                combined_content = " ".join(
-                    [chunk.content for chunk in user_file_chunks]
-                )
+            contents = content_by_file.get(user_file_id)
+            if contents:
+                combined_content = " ".join(contents)
                 user_file_id_to_raw_text[str(user_file_id)] = combined_content
                 token_count: int = (
                     count_tokens(combined_content, llm_tokenizer)
@@ -184,28 +177,16 @@ class UserFileIndexingAdapter:
                 user_file_id_to_raw_text[str(user_file_id)] = ""
                 user_file_id_to_token_count[str(user_file_id)] = None
 
-        access_aware_chunks = [
-            DocMetadataAwareIndexChunk.from_index_chunk(
-                index_chunk=chunk,
-                access=user_file_id_to_access.get(chunk.source_document.id, no_access),
-                document_sets=set(),
-                user_project=user_file_id_to_project_ids.get(
-                    chunk.source_document.id, []
-                ),
-                personas=user_file_id_to_persona_ids.get(chunk.source_document.id, []),
-                boost=DEFAULT_BOOST,
-                tenant_id=tenant_id,
-                aggregated_chunk_boost_factor=chunk_content_scores[chunk_num],
-            )
-            for chunk_num, chunk in enumerate(chunks_with_embeddings)
-        ]
-
-        return BuildMetadataAwareChunksResult(
-            chunks=access_aware_chunks,
+        return UserFileChunkEnricher(
+            user_file_id_to_access=user_file_id_to_access,
+            user_file_id_to_project_ids=user_file_id_to_project_ids,
+            user_file_id_to_persona_ids=user_file_id_to_persona_ids,
             doc_id_to_previous_chunk_cnt=user_file_id_to_previous_chunk_cnt,
-            doc_id_to_new_chunk_cnt=user_file_id_to_new_chunk_cnt,
+            doc_id_to_new_chunk_cnt=dict(doc_id_to_new_chunk_cnt),
             user_file_id_to_raw_text=user_file_id_to_raw_text,
             user_file_id_to_token_count=user_file_id_to_token_count,
+            no_access=no_access,
+            tenant_id=tenant_id,
         )
 
     def _notify_assistant_owners_if_files_ready(
@@ -249,8 +230,9 @@ class UserFileIndexingAdapter:
         context: DocumentBatchPrepareContext,
         updatable_chunk_data: list[UpdatableChunkData],  # noqa: ARG002
         filtered_documents: list[Document],  # noqa: ARG002
-        result: BuildMetadataAwareChunksResult,
+        enrichment: ChunkEnrichmentContext,
     ) -> None:
+        assert isinstance(enrichment, UserFileChunkEnricher)
         user_file_ids = [doc.id for doc in context.updatable_docs]
 
         user_files = (
@@ -266,8 +248,10 @@ class UserFileIndexingAdapter:
             user_file.last_project_sync_at = datetime.datetime.now(
                 datetime.timezone.utc
             )
-            user_file.chunk_count = result.doc_id_to_new_chunk_cnt[str(user_file.id)]
-            user_file.token_count = result.user_file_id_to_token_count[
+            user_file.chunk_count = enrichment.doc_id_to_new_chunk_cnt.get(
+                str(user_file.id), 0
+            )
+            user_file.token_count = enrichment.user_file_id_to_token_count[
                 str(user_file.id)
             ]
 
@@ -279,8 +263,54 @@ class UserFileIndexingAdapter:
         # Store the plaintext in the file store for faster retrieval
         # NOTE: this creates its own session to avoid committing the overall
         # transaction.
-        for user_file_id, raw_text in result.user_file_id_to_raw_text.items():
+        for user_file_id, raw_text in enrichment.user_file_id_to_raw_text.items():
             store_user_file_plaintext(
                 user_file_id=UUID(user_file_id),
                 plaintext_content=raw_text,
             )
+
+
+class UserFileChunkEnricher:
+    """Pre-computed metadata for per-chunk enrichment of user-uploaded files."""
+
+    def __init__(
+        self,
+        user_file_id_to_access: dict[str, DocumentAccess],
+        user_file_id_to_project_ids: dict[str, list[int]],
+        user_file_id_to_persona_ids: dict[str, list[int]],
+        doc_id_to_previous_chunk_cnt: dict[str, int],
+        doc_id_to_new_chunk_cnt: dict[str, int],
+        user_file_id_to_raw_text: dict[str, str],
+        user_file_id_to_token_count: dict[str, int | None],
+        no_access: DocumentAccess,
+        tenant_id: str,
+    ) -> None:
+        self._user_file_id_to_access = user_file_id_to_access
+        self._user_file_id_to_project_ids = user_file_id_to_project_ids
+        self._user_file_id_to_persona_ids = user_file_id_to_persona_ids
+        self._no_access = no_access
+        self._tenant_id = tenant_id
+        self.doc_id_to_previous_chunk_cnt = doc_id_to_previous_chunk_cnt
+        self.doc_id_to_new_chunk_cnt = doc_id_to_new_chunk_cnt
+        self.user_file_id_to_raw_text = user_file_id_to_raw_text
+        self.user_file_id_to_token_count = user_file_id_to_token_count
+
+    def enrich_chunk(
+        self, chunk: IndexChunk, score: float
+    ) -> DocMetadataAwareIndexChunk:
+        return DocMetadataAwareIndexChunk.from_index_chunk(
+            index_chunk=chunk,
+            access=self._user_file_id_to_access.get(
+                chunk.source_document.id, self._no_access
+            ),
+            document_sets=set(),
+            user_project=self._user_file_id_to_project_ids.get(
+                chunk.source_document.id, []
+            ),
+            personas=self._user_file_id_to_persona_ids.get(
+                chunk.source_document.id, []
+            ),
+            boost=DEFAULT_BOOST,
+            tenant_id=self._tenant_id,
+            aggregated_chunk_boost_factor=score,
+        )

backend/onyx/indexing/chunk_batch_store.py

@@ -0,0 +1,89 @@
+import pickle
+import shutil
+import tempfile
+from collections.abc import Iterator
+from pathlib import Path
+
+from onyx.indexing.models import IndexChunk
+
+
+class ChunkBatchStore:
+    """Manages serialization of embedded chunks to a temporary directory.
+
+    Owns the temp directory lifetime and provides save/load/stream/scrub
+    operations.
+
+    Use as a context manager to ensure cleanup::
+
+        with ChunkBatchStore() as store:
+            store.save(chunks, batch_idx=0)
+            for chunk in store.stream():
+                ...
+    """
+
+    _EXT = ".pkl"
+
+    def __init__(self) -> None:
+        self._tmpdir: Path | None = None
+
+    # -- context manager -----------------------------------------------------
+
+    def __enter__(self) -> "ChunkBatchStore":
+        self._tmpdir = Path(tempfile.mkdtemp(prefix="onyx_embeddings_"))
+        return self
+
+    def __exit__(self, *_exc: object) -> None:
+        if self._tmpdir is not None:
+            shutil.rmtree(self._tmpdir, ignore_errors=True)
+            self._tmpdir = None
+
+    @property
+    def _dir(self) -> Path:
+        assert self._tmpdir is not None, "ChunkBatchStore used outside context manager"
+        return self._tmpdir
+
+    # -- storage primitives --------------------------------------------------
+
+    def save(self, chunks: list[IndexChunk], batch_idx: int) -> None:
+        """Serialize a batch of embedded chunks to disk."""
+        with open(self._dir / f"batch_{batch_idx}{self._EXT}", "wb") as f:
+            pickle.dump(chunks, f)
+
+    def _load(self, batch_file: Path) -> list[IndexChunk]:
+        """Deserialize a batch of embedded chunks from a file."""
+        with open(batch_file, "rb") as f:
+            return pickle.load(f)
+
+    def _batch_files(self) -> list[Path]:
+        """Return batch files sorted by numeric index."""
+        return sorted(
+            self._dir.glob(f"batch_*{self._EXT}"),
+            key=lambda p: int(p.stem.removeprefix("batch_")),
+        )
+
+    # -- higher-level operations ---------------------------------------------
+
+    def stream(self) -> Iterator[IndexChunk]:
+        """Yield all chunks across all batch files.
+
+        Each call returns a fresh generator, so the data can be iterated
+        multiple times (e.g. once per document index).
+        """
+        for batch_file in self._batch_files():
+            yield from self._load(batch_file)
+
+    def scrub_failed_docs(self, failed_doc_ids: set[str]) -> None:
+        """Remove chunks belonging to *failed_doc_ids* from all batch files.
+
+        When a document fails embedding in batch N, earlier batches may
+        already contain successfully embedded chunks for that document.
+        This ensures the output is all-or-nothing per document.
+        """
+        for batch_file in self._batch_files():
+            batch_chunks = self._load(batch_file)
+            cleaned = [
+                c for c in batch_chunks if c.source_document.id not in failed_doc_ids
+            ]
+            if len(cleaned) != len(batch_chunks):
+                with open(batch_file, "wb") as f:
+                    pickle.dump(cleaned, f)

backend/onyx/indexing/indexing_pipeline.py

@@ -1,5 +1,8 @@
 from collections import defaultdict
 from collections.abc import Callable
+from collections.abc import Generator
+from collections.abc import Iterator
+from contextlib import contextmanager
 from typing import Protocol
 
 from pydantic import BaseModel
@@ -9,6 +12,7 @@ from sqlalchemy.orm import Session
 from onyx.configs.app_configs import DEFAULT_CONTEXTUAL_RAG_LLM_NAME
 from onyx.configs.app_configs import DEFAULT_CONTEXTUAL_RAG_LLM_PROVIDER
 from onyx.configs.app_configs import ENABLE_CONTEXTUAL_RAG
+from onyx.configs.app_configs import MAX_CHUNKS_PER_DOC_BATCH
 from onyx.configs.app_configs import MAX_DOCUMENT_CHARS
 from onyx.configs.app_configs import MAX_TOKENS_FOR_FULL_INCLUSION
 from onyx.configs.app_configs import USE_CHUNK_SUMMARY
@@ -43,10 +47,12 @@ from onyx.document_index.interfaces import DocumentMetadata
 from onyx.document_index.interfaces import IndexBatchParams
 from onyx.file_processing.image_summarization import summarize_image_with_error_handling
 from onyx.file_store.file_store import get_default_file_store
+from onyx.indexing.chunk_batch_store import ChunkBatchStore
 from onyx.indexing.chunker import Chunker
 from onyx.indexing.embedder import embed_chunks_with_failure_handling
 from onyx.indexing.embedder import IndexingEmbedder
 from onyx.indexing.models import DocAwareChunk
+from onyx.indexing.models import DocMetadataAwareIndexChunk
 from onyx.indexing.models import IndexingBatchAdapter
 from onyx.indexing.models import UpdatableChunkData
 from onyx.indexing.vector_db_insertion import write_chunks_to_vector_db_with_backoff
@@ -63,6 +69,7 @@ from onyx.natural_language_processing.utils import tokenizer_trim_middle
 from onyx.prompts.contextual_retrieval import CONTEXTUAL_RAG_PROMPT1
 from onyx.prompts.contextual_retrieval import CONTEXTUAL_RAG_PROMPT2
 from onyx.prompts.contextual_retrieval import DOCUMENT_SUMMARY_PROMPT
+from onyx.utils.batching import batch_generator
 from onyx.utils.logger import setup_logger
 from onyx.utils.postgres_sanitization import sanitize_documents_for_postgres
 from onyx.utils.threadpool_concurrency import run_functions_tuples_in_parallel
@@ -91,6 +98,20 @@ class IndexingPipelineResult(BaseModel):
 
     failures: list[ConnectorFailure]
 
+    @classmethod
+    def empty(cls, total_docs: int) -> "IndexingPipelineResult":
+        return cls(
+            new_docs=0,
+            total_docs=total_docs,
+            total_chunks=0,
+            failures=[],
+        )
+
+
+class ChunkEmbeddingResult(BaseModel):
+    successful_chunk_ids: list[tuple[int, str]]  # (chunk_id, document_id)
+    connector_failures: list[ConnectorFailure]
+
 
 class IndexingPipelineProtocol(Protocol):
     def __call__(
@@ -139,6 +160,110 @@ def _upsert_documents_in_db(
         )
 
 
+def _get_failed_doc_ids(failures: list[ConnectorFailure]) -> set[str]:
+    """Extract document IDs from a list of connector failures."""
+    return {f.failed_document.document_id for f in failures if f.failed_document}
+
+
+def _embed_chunks_to_store(
+    chunks: list[DocAwareChunk],
+    embedder: IndexingEmbedder,
+    tenant_id: str,
+    request_id: str | None,
+    store: ChunkBatchStore,
+) -> ChunkEmbeddingResult:
+    """Embed chunks in batches, spilling each batch to *store*.
+
+    If a document fails embedding in any batch, its chunks are excluded from
+    all batches (including earlier ones already written) so that the output
+    is all-or-nothing per document.
+    """
+    successful_chunk_ids: list[tuple[int, str]] = []
+    all_embedding_failures: list[ConnectorFailure] = []
+    # Track failed doc IDs across all batches so that a failure in batch N
+    # causes chunks for that doc to be skipped in batch N+1 and stripped
+    # from earlier batches.
+    all_failed_doc_ids: set[str] = set()
+
+    for batch_idx, chunk_batch in enumerate(
+        batch_generator(chunks, MAX_CHUNKS_PER_DOC_BATCH)
+    ):
+        # Skip chunks belonging to documents that failed in earlier batches.
+        chunk_batch = [
+            c for c in chunk_batch if c.source_document.id not in all_failed_doc_ids
+        ]
+        if not chunk_batch:
+            continue
+
+        logger.debug(f"Embedding batch {batch_idx}: {len(chunk_batch)} chunks")
+
+        chunks_with_embeddings, embedding_failures = embed_chunks_with_failure_handling(
+            chunks=chunk_batch,
+            embedder=embedder,
+            tenant_id=tenant_id,
+            request_id=request_id,
+        )
+        all_embedding_failures.extend(embedding_failures)
+        all_failed_doc_ids.update(_get_failed_doc_ids(embedding_failures))
+
+        # Only keep successfully embedded chunks for non-failed docs.
+        chunks_with_embeddings = [
+            c
+            for c in chunks_with_embeddings
+            if c.source_document.id not in all_failed_doc_ids
+        ]
+
+        successful_chunk_ids.extend(
+            (c.chunk_id, c.source_document.id) for c in chunks_with_embeddings
+        )
+
+        store.save(chunks_with_embeddings, batch_idx)
+        del chunks_with_embeddings
+
+    # Scrub earlier batches for docs that failed in later batches.
+    if all_failed_doc_ids:
+        store.scrub_failed_docs(all_failed_doc_ids)
+        successful_chunk_ids = [
+            (chunk_id, doc_id)
+            for chunk_id, doc_id in successful_chunk_ids
+            if doc_id not in all_failed_doc_ids
+        ]
+
+    return ChunkEmbeddingResult(
+        successful_chunk_ids=successful_chunk_ids,
+        connector_failures=all_embedding_failures,
+    )
+
+
+@contextmanager
+def embed_and_stream(
+    chunks: list[DocAwareChunk],
+    embedder: IndexingEmbedder,
+    tenant_id: str,
+    request_id: str | None,
+) -> Generator[tuple[ChunkEmbeddingResult, ChunkBatchStore], None, None]:
+    """Embed chunks to disk and yield a ``(result, store)`` pair.
+
+    The store owns the temp directory — files are cleaned up when the context
+    manager exits.
+
+    Usage::
+
+        with embed_and_stream(chunks, embedder, tenant_id, req_id) as (result, store):
+            for chunk in store.stream():
+                ...
+    """
+    with ChunkBatchStore() as store:
+        result = _embed_chunks_to_store(
+            chunks=chunks,
+            embedder=embedder,
+            tenant_id=tenant_id,
+            request_id=request_id,
+            store=store,
+        )
+        yield result, store
+
+
 def get_doc_ids_to_update(
     documents: list[Document], db_docs: list[DBDocument]
 ) -> list[Document]:
@@ -637,6 +762,29 @@ def add_contextual_summaries(
     return chunks
 
 
+def _verify_indexing_completeness(
+    insertion_records: list[DocumentInsertionRecord],
+    write_failures: list[ConnectorFailure],
+    embedding_failed_doc_ids: set[str],
+    updatable_ids: list[str],
+    document_index_name: str,
+) -> None:
+    """Verify that every updatable document was either indexed or reported as failed."""
+    all_returned_doc_ids = (
+        {r.document_id for r in insertion_records}
+        | {f.failed_document.document_id for f in write_failures if f.failed_document}
+        | embedding_failed_doc_ids
+    )
+    if all_returned_doc_ids != set(updatable_ids):
+        raise RuntimeError(
+            f"Some documents were not successfully indexed. "
+            f"Updatable IDs: {updatable_ids}, "
+            f"Returned IDs: {all_returned_doc_ids}. "
+            f"This should never happen. "
+            f"This occured for document index {document_index_name}"
+        )
+
+
 @log_function_time(debug_only=True)
 def index_doc_batch(
     *,
@@ -672,12 +820,7 @@ def index_doc_batch(
     filtered_documents = filter_fnc(document_batch)
     context = adapter.prepare(filtered_documents, ignore_time_skip)
     if not context:
-        return IndexingPipelineResult(
-            new_docs=0,
-            total_docs=len(filtered_documents),
-            total_chunks=0,
-            failures=[],
-        )
+        return IndexingPipelineResult.empty(len(filtered_documents))
 
     # Convert documents to IndexingDocument objects with processed section
     # logger.debug("Processing image sections")
@@ -716,117 +859,99 @@ def index_doc_batch(
         )
 
     logger.debug("Starting embedding")
-    chunks_with_embeddings, embedding_failures = (
-        embed_chunks_with_failure_handling(
-            chunks=chunks,
-            embedder=embedder,
-            tenant_id=tenant_id,
-            request_id=request_id,
-        )
-        if chunks
-        else ([], [])
-    )
+    with embed_and_stream(chunks, embedder, tenant_id, request_id) as (
+        embedding_result,
+        chunk_store,
+    ):
+        updatable_ids = [doc.id for doc in context.updatable_docs]
+        updatable_chunk_data = [
+            UpdatableChunkData(
+                chunk_id=chunk_id,
+                document_id=document_id,
+                boost_score=1.0,
+            )
+            for chunk_id, document_id in embedding_result.successful_chunk_ids
+        ]
 
-    chunk_content_scores = [1.0] * len(chunks_with_embeddings)
-
-    updatable_ids = [doc.id for doc in context.updatable_docs]
-    updatable_chunk_data = [
-        UpdatableChunkData(
-            chunk_id=chunk.chunk_id,
-            document_id=chunk.source_document.id,
-            boost_score=score,
-        )
-        for chunk, score in zip(chunks_with_embeddings, chunk_content_scores)
-    ]
-
-    # Acquires a lock on the documents so that no other process can modify them
-    # NOTE: don't need to acquire till here, since this is when the actual race condition
-    # with Vespa can occur.
-    with adapter.lock_context(context.updatable_docs):
-        # we're concerned about race conditions where multiple simultaneous indexings might result
-        # in one set of metadata overwriting another one in vespa.
-        # we still write data here for the immediate and most likely correct sync, but
-        # to resolve this, an update of the last modified field at the end of this loop
-        # always triggers a final metadata sync via the celery queue
-        result = adapter.build_metadata_aware_chunks(
-            chunks_with_embeddings=chunks_with_embeddings,
-            chunk_content_scores=chunk_content_scores,
-            tenant_id=tenant_id,
-            context=context,
+        embedding_failed_doc_ids = _get_failed_doc_ids(
+            embedding_result.connector_failures
         )
 
-        short_descriptor_list = [chunk.to_short_descriptor() for chunk in result.chunks]
-        short_descriptor_log = str(short_descriptor_list)[:1024]
-        logger.debug(f"Indexing the following chunks: {short_descriptor_log}")
+        # Filter to only successfully embedded chunks so
+        # doc_id_to_new_chunk_cnt reflects what's actually written to Vespa.
+        embedded_chunks = [
+            c for c in chunks if c.source_document.id not in embedding_failed_doc_ids
+        ]
 
-        primary_doc_idx_insertion_records: list[DocumentInsertionRecord] | None = None
-        primary_doc_idx_vector_db_write_failures: list[ConnectorFailure] | None = None
-        for document_index in document_indices:
-            # A document will not be spread across different batches, so all the
-            # documents with chunks in this set, are fully represented by the chunks
-            # in this set
-            (
-                insertion_records,
-                vector_db_write_failures,
-            ) = write_chunks_to_vector_db_with_backoff(
-                document_index=document_index,
-                chunks=result.chunks,
-                index_batch_params=IndexBatchParams(
-                    doc_id_to_previous_chunk_cnt=result.doc_id_to_previous_chunk_cnt,
-                    doc_id_to_new_chunk_cnt=result.doc_id_to_new_chunk_cnt,
-                    tenant_id=tenant_id,
-                    large_chunks_enabled=chunker.enable_large_chunks,
-                ),
+        # Acquires a lock on the documents so that no other process can modify
+        # them.  Not needed until here, since this is when the actual race
+        # condition with vector db can occur.
+        with adapter.lock_context(context.updatable_docs):
+            enricher = adapter.prepare_enrichment(
+                context=context,
+                tenant_id=tenant_id,
+                chunks=embedded_chunks,
             )
 
-            all_returned_doc_ids: set[str] = (
-                {record.document_id for record in insertion_records}
-                .union(
-                    {
-                        record.failed_document.document_id
-                        for record in vector_db_write_failures
-                        if record.failed_document
-                    }
-                )
-                .union(
-                    {
-                        record.failed_document.document_id
-                        for record in embedding_failures
-                        if record.failed_document
-                    }
-                )
+            index_batch_params = IndexBatchParams(
+                doc_id_to_previous_chunk_cnt=enricher.doc_id_to_previous_chunk_cnt,
+                doc_id_to_new_chunk_cnt=enricher.doc_id_to_new_chunk_cnt,
+                tenant_id=tenant_id,
+                large_chunks_enabled=chunker.enable_large_chunks,
             )
-            if all_returned_doc_ids != set(updatable_ids):
-                raise RuntimeError(
-                    f"Some documents were not successfully indexed. "
-                    f"Updatable IDs: {updatable_ids}, "
-                    f"Returned IDs: {all_returned_doc_ids}. "
-                    "This should never happen."
-                    f"This occured for document index {document_index.__class__.__name__}"
-                )
-            # We treat the first document index we got as the primary one used
-            # for reporting the state of indexing.
-            if primary_doc_idx_insertion_records is None:
-                primary_doc_idx_insertion_records = insertion_records
-            if primary_doc_idx_vector_db_write_failures is None:
-                primary_doc_idx_vector_db_write_failures = vector_db_write_failures
 
-        adapter.post_index(
-            context=context,
-            updatable_chunk_data=updatable_chunk_data,
-            filtered_documents=filtered_documents,
-            result=result,
-        )
+            primary_doc_idx_insertion_records: list[DocumentInsertionRecord] | None = (
+                None
+            )
+            primary_doc_idx_vector_db_write_failures: list[ConnectorFailure] | None = (
+                None
+            )
+
+            for document_index in document_indices:
+
+                def _enriched_stream() -> Iterator[DocMetadataAwareIndexChunk]:
+                    for chunk in chunk_store.stream():
+                        yield enricher.enrich_chunk(chunk, 1.0)
+
+                insertion_records, write_failures = (
+                    write_chunks_to_vector_db_with_backoff(
+                        document_index=document_index,
+                        make_chunks=_enriched_stream,
+                        index_batch_params=index_batch_params,
+                    )
+                )
+
+                _verify_indexing_completeness(
+                    insertion_records=insertion_records,
+                    write_failures=write_failures,
+                    embedding_failed_doc_ids=embedding_failed_doc_ids,
+                    updatable_ids=updatable_ids,
+                    document_index_name=document_index.__class__.__name__,
+                )
+                # We treat the first document index we got as the primary one used
+                # for reporting the state of indexing.
+                if primary_doc_idx_insertion_records is None:
+                    primary_doc_idx_insertion_records = insertion_records
+                if primary_doc_idx_vector_db_write_failures is None:
+                    primary_doc_idx_vector_db_write_failures = write_failures
+
+            adapter.post_index(
+                context=context,
+                updatable_chunk_data=updatable_chunk_data,
+                filtered_documents=filtered_documents,
+                enrichment=enricher,
+            )
 
     assert primary_doc_idx_insertion_records is not None
     assert primary_doc_idx_vector_db_write_failures is not None
     return IndexingPipelineResult(
-        new_docs=len(
-            [r for r in primary_doc_idx_insertion_records if not r.already_existed]
+        new_docs=sum(
+            1 for r in primary_doc_idx_insertion_records if not r.already_existed
         ),
         total_docs=len(filtered_documents),
-        total_chunks=len(chunks_with_embeddings),
-        failures=primary_doc_idx_vector_db_write_failures + embedding_failures,
+        total_chunks=len(embedding_result.successful_chunk_ids),
+        failures=primary_doc_idx_vector_db_write_failures
+        + embedding_result.connector_failures,
     )
 
 

backend/onyx/indexing/models.py

@@ -235,12 +235,16 @@ class UpdatableChunkData(BaseModel):
     boost_score: float
 
 
-class BuildMetadataAwareChunksResult(BaseModel):
-    chunks: list[DocMetadataAwareIndexChunk]
+class ChunkEnrichmentContext(Protocol):
+    """Returned by prepare_enrichment. Holds pre-computed metadata lookups
+    and provides per-chunk enrichment."""
+
     doc_id_to_previous_chunk_cnt: dict[str, int]
     doc_id_to_new_chunk_cnt: dict[str, int]
-    user_file_id_to_raw_text: dict[str, str]
-    user_file_id_to_token_count: dict[str, int | None]
+
+    def enrich_chunk(
+        self, chunk: IndexChunk, score: float
+    ) -> DocMetadataAwareIndexChunk: ...
 
 
 class IndexingBatchAdapter(Protocol):
@@ -254,18 +258,24 @@ class IndexingBatchAdapter(Protocol):
     ) -> Generator[TransactionalContext, None, None]:
         """Provide a transaction/row-lock context for critical updates."""
 
-    def build_metadata_aware_chunks(
+    def prepare_enrichment(
         self,
-        chunks_with_embeddings: list[IndexChunk],
-        chunk_content_scores: list[float],
-        tenant_id: str,
         context: "DocumentBatchPrepareContext",
-    ) -> BuildMetadataAwareChunksResult: ...
+        tenant_id: str,
+        chunks: list[DocAwareChunk],
+    ) -> ChunkEnrichmentContext:
+        """Prepare per-chunk enrichment data (access, document sets, boost, etc.).
+
+        Precondition: ``chunks`` have already been through the embedding step
+        (i.e. they are ``IndexChunk`` instances with populated embeddings,
+        passed here as the base ``DocAwareChunk`` type).
+        """
+        ...
 
     def post_index(
         self,
         context: "DocumentBatchPrepareContext",
         updatable_chunk_data: list[UpdatableChunkData],
         filtered_documents: list[Document],
-        result: BuildMetadataAwareChunksResult,
+        enrichment: ChunkEnrichmentContext,
     ) -> None: ...

backend/onyx/indexing/vector_db_insertion.py

@@ -1,6 +1,9 @@
 import time
-from collections import defaultdict
+from collections.abc import Callable
+from collections.abc import Iterable
 from http import HTTPStatus
+from itertools import chain
+from itertools import groupby
 
 import httpx
 
@@ -28,22 +31,22 @@ def _log_insufficient_storage_error(e: Exception) -> None:
 
 def write_chunks_to_vector_db_with_backoff(
     document_index: DocumentIndex,
-    chunks: list[DocMetadataAwareIndexChunk],
+    make_chunks: Callable[[], Iterable[DocMetadataAwareIndexChunk]],
     index_batch_params: IndexBatchParams,
 ) -> tuple[list[DocumentInsertionRecord], list[ConnectorFailure]]:
     """Tries to insert all chunks in one large batch. If that batch fails for any reason,
     goes document by document to isolate the failure(s).
 
     IMPORTANT: must pass in whole documents at a time not individual chunks, since the
-    vector DB interface assumes that all chunks for a single document are present.
+    vector DB interface assumes that all chunks for a single document are present. The
+    chunks must also be in contiguous batches
     """
-
     # first try to write the chunks to the vector db
     try:
         return (
             list(
                 document_index.index(
-                    chunks=chunks,
+                    chunks=make_chunks(),
                     index_batch_params=index_batch_params,
                 )
             ),
@@ -60,14 +63,23 @@ def write_chunks_to_vector_db_with_backoff(
         # wait a couple seconds just to give the vector db a chance to recover
         time.sleep(2)
 
-    # try writing each doc one by one
-    chunks_for_docs: dict[str, list[DocMetadataAwareIndexChunk]] = defaultdict(list)
-    for chunk in chunks:
-        chunks_for_docs[chunk.source_document.id].append(chunk)
-
     insertion_records: list[DocumentInsertionRecord] = []
     failures: list[ConnectorFailure] = []
-    for doc_id, chunks_for_doc in chunks_for_docs.items():
+
+    def key(chunk: DocMetadataAwareIndexChunk) -> str:
+        return chunk.source_document.id
+
+    seen_doc_ids: set[str] = set()
+    for doc_id, chunks_for_doc in groupby(make_chunks(), key=key):
+        if doc_id in seen_doc_ids:
+            raise RuntimeError(
+                f"Doc chunks are not arriving in order. Current doc_id={doc_id}, seen_doc_ids={list(seen_doc_ids)}"
+            )
+        seen_doc_ids.add(doc_id)
+
+        first_chunk = next(chunks_for_doc)
+        chunks_for_doc = chain([first_chunk], chunks_for_doc)
+
         try:
             insertion_records.extend(
                 document_index.index(
@@ -87,9 +99,7 @@ def write_chunks_to_vector_db_with_backoff(
                 ConnectorFailure(
                     failed_document=DocumentFailure(
                         document_id=doc_id,
-                        document_link=(
-                            chunks_for_doc[0].get_link() if chunks_for_doc else None
-                        ),
+                        document_link=first_chunk.get_link(),
                     ),
                     failure_message=str(e),
                     exception=e,

backend/onyx/llm/override_models.py

@@ -8,6 +8,24 @@ from pydantic import BaseModel
 
 
 class LLMOverride(BaseModel):
+    """Per-request LLM settings that override persona defaults.
+
+    All fields are optional — only the fields that differ from the persona's
+    configured LLM need to be supplied. Used both over the wire (API requests)
+    and for multi-model comparison, where one override is supplied per model.
+
+    Attributes:
+        model_provider: LLM provider slug (e.g. ``"openai"``, ``"anthropic"``).
+            When ``None``, the persona's default provider is used.
+        model_version: Specific model version string (e.g. ``"gpt-4o"``).
+            When ``None``, the persona's default model is used.
+        temperature: Sampling temperature in ``[0, 2]``. When ``None``, the
+            persona's default temperature is used.
+        display_name: Human-readable label shown in the UI for this model,
+            e.g. ``"GPT-4 Turbo"``. Optional; falls back to ``model_version``
+            when not set.
+    """
+
     model_provider: str | None = None
     model_version: str | None = None
     temperature: float | None = None

backend/onyx/server/query_and_chat/chat_backend.py

@@ -28,6 +28,7 @@ from onyx.chat.chat_utils import extract_headers
 from onyx.chat.models import ChatFullResponse
 from onyx.chat.models import CreateChatSessionID
 from onyx.chat.process_message import gather_stream_full
+from onyx.chat.process_message import handle_multi_model_stream
 from onyx.chat.process_message import handle_stream_message_objects
 from onyx.chat.prompt_utils import get_default_base_system_prompt
 from onyx.chat.stop_signal_checker import set_fence
@@ -46,6 +47,7 @@ from onyx.db.chat import get_chat_messages_by_session
 from onyx.db.chat import get_chat_session_by_id
 from onyx.db.chat import get_chat_sessions_by_user
 from onyx.db.chat import set_as_latest_chat_message
+from onyx.db.chat import set_preferred_response
 from onyx.db.chat import translate_db_message_to_chat_message_detail
 from onyx.db.chat import update_chat_session
 from onyx.db.chat_search import search_chat_sessions
@@ -60,6 +62,8 @@ from onyx.db.persona import get_persona_by_id
 from onyx.db.usage import increment_usage
 from onyx.db.usage import UsageType
 from onyx.db.user_file import get_file_id_by_user_file_id
+from onyx.error_handling.error_codes import OnyxErrorCode
+from onyx.error_handling.exceptions import OnyxError
 from onyx.file_store.file_store import get_default_file_store
 from onyx.llm.constants import LlmProviderNames
 from onyx.llm.factory import get_default_llm
@@ -81,6 +85,7 @@ from onyx.server.query_and_chat.models import ChatSessionUpdateRequest
 from onyx.server.query_and_chat.models import MessageOrigin
 from onyx.server.query_and_chat.models import RenameChatSessionResponse
 from onyx.server.query_and_chat.models import SendMessageRequest
+from onyx.server.query_and_chat.models import SetPreferredResponseRequest
 from onyx.server.query_and_chat.models import UpdateChatSessionTemperatureRequest
 from onyx.server.query_and_chat.models import UpdateChatSessionThreadRequest
 from onyx.server.query_and_chat.session_loading import (
@@ -570,6 +575,46 @@ def handle_send_chat_message(
     if get_hashed_api_key_from_request(request) or get_hashed_pat_from_request(request):
         chat_message_req.origin = MessageOrigin.API
 
+    # Multi-model streaming path: 2-3 LLMs in parallel (streaming only)
+    is_multi_model = (
+        chat_message_req.llm_overrides is not None
+        and len(chat_message_req.llm_overrides) > 1
+    )
+    if is_multi_model and chat_message_req.stream:
+        # Narrowed here; is_multi_model already checked llm_overrides is not None
+        llm_overrides = chat_message_req.llm_overrides or []
+
+        def multi_model_stream_generator() -> Generator[str, None, None]:
+            try:
+                with get_session_with_current_tenant() as db_session:
+                    for obj in handle_multi_model_stream(
+                        new_msg_req=chat_message_req,
+                        user=user,
+                        db_session=db_session,
+                        llm_overrides=llm_overrides,
+                        litellm_additional_headers=extract_headers(
+                            request.headers, LITELLM_PASS_THROUGH_HEADERS
+                        ),
+                        custom_tool_additional_headers=get_custom_tool_additional_request_headers(
+                            request.headers
+                        ),
+                        mcp_headers=chat_message_req.mcp_headers,
+                    ):
+                        yield get_json_line(obj.model_dump())
+            except Exception as e:
+                logger.exception("Error in multi-model streaming")
+                yield json.dumps({"error": str(e)})
+
+        return StreamingResponse(
+            multi_model_stream_generator(), media_type="text/event-stream"
+        )
+
+    if is_multi_model and not chat_message_req.stream:
+        raise OnyxError(
+            OnyxErrorCode.INVALID_INPUT,
+            "Multi-model mode (llm_overrides with >1 entry) requires stream=True.",
+        )
+
     # Non-streaming path: consume all packets and return complete response
     if not chat_message_req.stream:
         with get_session_with_current_tenant() as db_session:
@@ -660,6 +705,30 @@ def set_message_as_latest(
     )
 
 
+@router.put("/set-preferred-response")
+def set_preferred_response_endpoint(
+    request_body: SetPreferredResponseRequest,
+    user: User | None = Depends(current_user),
+    db_session: Session = Depends(get_session),
+) -> None:
+    """Set the preferred assistant response for a multi-model turn."""
+    try:
+        # Ownership check: get_chat_message raises ValueError if the message
+        # doesn't belong to this user, preventing cross-user mutation.
+        get_chat_message(
+            chat_message_id=request_body.user_message_id,
+            user_id=user.id if user else None,
+            db_session=db_session,
+        )
+        set_preferred_response(
+            db_session=db_session,
+            user_message_id=request_body.user_message_id,
+            preferred_assistant_message_id=request_body.preferred_response_id,
+        )
+    except ValueError as e:
+        raise OnyxError(OnyxErrorCode.INVALID_INPUT, str(e))
+
+
 @router.post("/create-chat-message-feedback")
 def create_chat_feedback(
     feedback: ChatFeedbackRequest,

backend/onyx/server/query_and_chat/placement.py

@@ -2,11 +2,25 @@ from pydantic import BaseModel
 
 
 class Placement(BaseModel):
-    # Which iterative block in the UI is this part of, these are ordered and smaller ones happened first
+    """Coordinates that identify where a streaming packet belongs in the UI.
+
+    The frontend uses these fields to route each packet to the correct turn,
+    tool tab, agent sub-turn, and (in multi-model mode) response column.
+
+    Attributes:
+        turn_index: Monotonically increasing index of the iterative reasoning block
+            (e.g. tool call round) within this chat message. Lower values happened first.
+        tab_index: Disambiguates parallel tool calls within the same turn so each
+            tool's output can be displayed in its own tab.
+        sub_turn_index: Nesting level for tools that invoke other tools. ``None`` for
+            top-level packets; an integer for tool-within-tool output.
+        model_index: Which model this packet belongs to. ``0`` for single-model
+            responses; ``0``, ``1``, or ``2`` for multi-model comparison. ``None``
+            for pre-LLM setup packets (e.g. message ID info) that are yielded
+            before any Emitter runs.
+    """
+
     turn_index: int
-    # For parallel tool calls to preserve order of execution
     tab_index: int = 0
-    # Used for tools/agents that call other tools, this currently doesn't support nested agents but can be added later
     sub_turn_index: int | None = None
-    # For multi-model streaming: identifies which model (0, 1, 2) this packet belongs to.
     model_index: int | None = None

backend/onyx/tools/fake_tools/research_agent.py

@@ -1,3 +1,4 @@
+import queue
 import time
 from collections.abc import Callable
 from typing import Any
@@ -708,7 +709,6 @@ def run_research_agent_calls(
 
 
 if __name__ == "__main__":
-    from queue import Queue
     from uuid import uuid4
 
     from onyx.chat.chat_state import ChatStateContainer
@@ -744,8 +744,8 @@ if __name__ == "__main__":
         if user is None:
             raise ValueError("No users found in database. Please create a user first.")
 
-        bus: Queue[Packet] = Queue()
-        emitter = Emitter(bus)
+        emitter_queue: queue.Queue = queue.Queue()
+        emitter = Emitter(merged_queue=emitter_queue)
         state_container = ChatStateContainer()
 
         tool_dict = construct_tools(
@@ -792,4 +792,4 @@ if __name__ == "__main__":
             print(result.intermediate_report)
             print("=" * 80)
             print(f"Citations: {result.citation_mapping}")
-            print(f"Total packets emitted: {bus.qsize()}")
+            print(f"Total packets emitted: {emitter_queue.qsize()}")

backend/onyx/tools/tool_implementations/custom/custom_tool.py

@@ -1,5 +1,6 @@
 import csv
 import json
+import queue
 import uuid
 from io import BytesIO
 from io import StringIO
@@ -11,7 +12,6 @@ import requests
 from requests import JSONDecodeError
 
 from onyx.chat.emitter import Emitter
-from onyx.chat.emitter import get_default_emitter
 from onyx.configs.constants import FileOrigin
 from onyx.file_store.file_store import get_default_file_store
 from onyx.server.query_and_chat.placement import Placement
@@ -296,9 +296,9 @@ def build_custom_tools_from_openapi_schema_and_headers(
     url = openapi_to_url(openapi_schema)
     method_specs = openapi_to_method_specs(openapi_schema)
 
-    # Use default emitter if none provided
+    # Use a discard emitter if none provided (packets go nowhere)
     if emitter is None:
-        emitter = get_default_emitter()
+        emitter = Emitter(merged_queue=queue.Queue())
 
     return [
         CustomTool(
@@ -367,7 +367,7 @@ if __name__ == "__main__":
     tools = build_custom_tools_from_openapi_schema_and_headers(
         tool_id=0,  # dummy tool id
         openapi_schema=openapi_schema,
-        emitter=get_default_emitter(),
+        emitter=Emitter(merged_queue=queue.Queue()),
         dynamic_schema_info=None,
     )
 

backend/requirements/default.txt

@@ -735,7 +735,7 @@ pyee==13.0.0
     # via playwright
 pygithub==2.5.0
     # via onyx
-pygments==2.19.2
+pygments==2.20.0
     # via rich
 pyjwt==2.12.0
     # via

backend/requirements/dev.txt

@@ -349,7 +349,7 @@ pydantic-core==2.33.2
     # via pydantic
 pydantic-settings==2.12.0
     # via mcp
-pygments==2.19.2
+pygments==2.20.0
     # via
     #   ipython
     #   ipython-pygments-lexers

backend/tests/external_dependency_unit/answer/stream_test_utils.py

@@ -27,11 +27,13 @@ def create_placement(
     turn_index: int,
     tab_index: int = 0,
     sub_turn_index: int | None = None,
+    model_index: int | None = 0,
 ) -> Placement:
     return Placement(
         turn_index=turn_index,
         tab_index=tab_index,
         sub_turn_index=sub_turn_index,
+        model_index=model_index,
     )
 
 

backend/tests/external_dependency_unit/celery/test_user_file_indexing_adapter.py

@@ -1,7 +1,7 @@
 """
 External dependency unit tests for UserFileIndexingAdapter metadata writing.
 
-Validates that build_metadata_aware_chunks produces DocMetadataAwareIndexChunk
+Validates that prepare_enrichment produces DocMetadataAwareIndexChunk
 objects with both `user_project` and `personas` fields populated correctly
 based on actual DB associations.
 
@@ -127,7 +127,7 @@ def _make_index_chunk(user_file: UserFile) -> IndexChunk:
 
 
 class TestAdapterWritesBothMetadataFields:
-    """build_metadata_aware_chunks must populate user_project AND personas."""
+    """prepare_enrichment must populate user_project AND personas."""
 
     @patch(
         "onyx.indexing.adapters.user_file_indexing_adapter.get_default_llm",
@@ -153,15 +153,13 @@ class TestAdapterWritesBothMetadataFields:
         doc = chunk.source_document
         context = DocumentBatchPrepareContext(updatable_docs=[doc], id_to_boost_map={})
 
-        result = adapter.build_metadata_aware_chunks(
-            chunks_with_embeddings=[chunk],
-            chunk_content_scores=[1.0],
-            tenant_id=TEST_TENANT_ID,
+        enricher = adapter.prepare_enrichment(
             context=context,
+            tenant_id=TEST_TENANT_ID,
+            chunks=[chunk],
         )
+        aware_chunk = enricher.enrich_chunk(chunk, 1.0)
 
-        assert len(result.chunks) == 1
-        aware_chunk = result.chunks[0]
         assert persona.id in aware_chunk.personas
         assert aware_chunk.user_project == []
 
@@ -190,15 +188,13 @@ class TestAdapterWritesBothMetadataFields:
             updatable_docs=[chunk.source_document], id_to_boost_map={}
         )
 
-        result = adapter.build_metadata_aware_chunks(
-            chunks_with_embeddings=[chunk],
-            chunk_content_scores=[1.0],
-            tenant_id=TEST_TENANT_ID,
+        enricher = adapter.prepare_enrichment(
             context=context,
+            tenant_id=TEST_TENANT_ID,
+            chunks=[chunk],
         )
+        aware_chunk = enricher.enrich_chunk(chunk, 1.0)
 
-        assert len(result.chunks) == 1
-        aware_chunk = result.chunks[0]
         assert project.id in aware_chunk.user_project
         assert aware_chunk.personas == []
 
@@ -229,14 +225,13 @@ class TestAdapterWritesBothMetadataFields:
             updatable_docs=[chunk.source_document], id_to_boost_map={}
         )
 
-        result = adapter.build_metadata_aware_chunks(
-            chunks_with_embeddings=[chunk],
-            chunk_content_scores=[1.0],
-            tenant_id=TEST_TENANT_ID,
+        enricher = adapter.prepare_enrichment(
             context=context,
+            tenant_id=TEST_TENANT_ID,
+            chunks=[chunk],
         )
+        aware_chunk = enricher.enrich_chunk(chunk, 1.0)
 
-        aware_chunk = result.chunks[0]
         assert persona.id in aware_chunk.personas
         assert project.id in aware_chunk.user_project
 
@@ -261,14 +256,13 @@ class TestAdapterWritesBothMetadataFields:
             updatable_docs=[chunk.source_document], id_to_boost_map={}
         )
 
-        result = adapter.build_metadata_aware_chunks(
-            chunks_with_embeddings=[chunk],
-            chunk_content_scores=[1.0],
-            tenant_id=TEST_TENANT_ID,
+        enricher = adapter.prepare_enrichment(
             context=context,
+            tenant_id=TEST_TENANT_ID,
+            chunks=[chunk],
         )
+        aware_chunk = enricher.enrich_chunk(chunk, 1.0)
 
-        aware_chunk = result.chunks[0]
         assert aware_chunk.personas == []
         assert aware_chunk.user_project == []
 
@@ -300,12 +294,11 @@ class TestAdapterWritesBothMetadataFields:
             updatable_docs=[chunk.source_document], id_to_boost_map={}
         )
 
-        result = adapter.build_metadata_aware_chunks(
-            chunks_with_embeddings=[chunk],
-            chunk_content_scores=[1.0],
-            tenant_id=TEST_TENANT_ID,
+        enricher = adapter.prepare_enrichment(
             context=context,
+            tenant_id=TEST_TENANT_ID,
+            chunks=[chunk],
         )
+        aware_chunk = enricher.enrich_chunk(chunk, 1.0)
 
-        aware_chunk = result.chunks[0]
         assert set(aware_chunk.personas) == {persona_a.id, persona_b.id}

backend/tests/external_dependency_unit/tools/test_mcp_passthrough_oauth.py

@@ -13,6 +13,7 @@ This test:
 All external HTTP calls are mocked, but Postgres and Redis are running.
 """
 
+import queue
 from typing import Any
 from unittest.mock import patch
 from uuid import uuid4
@@ -20,7 +21,7 @@ from uuid import uuid4
 import pytest
 from sqlalchemy.orm import Session
 
-from onyx.chat.emitter import get_default_emitter
+from onyx.chat.emitter import Emitter
 from onyx.db.enums import MCPAuthenticationPerformer
 from onyx.db.enums import MCPAuthenticationType
 from onyx.db.enums import MCPTransport
@@ -137,7 +138,7 @@ class TestMCPPassThroughOAuth:
         tool_dict = construct_tools(
             persona=persona,
             db_session=db_session,
-            emitter=get_default_emitter(),
+            emitter=Emitter(merged_queue=queue.Queue()),
             user=user,
             llm=llm,
             search_tool_config=search_tool_config,
@@ -200,7 +201,7 @@ class TestMCPPassThroughOAuth:
         tool_dict = construct_tools(
             persona=persona,
             db_session=db_session,
-            emitter=get_default_emitter(),
+            emitter=Emitter(merged_queue=queue.Queue()),
             user=user,
             llm=llm,
             search_tool_config=SearchToolConfig(),
@@ -275,7 +276,7 @@ class TestMCPPassThroughOAuth:
         tool_dict = construct_tools(
             persona=persona,
             db_session=db_session,
-            emitter=get_default_emitter(),
+            emitter=Emitter(merged_queue=queue.Queue()),
             user=user,
             llm=llm,
             search_tool_config=SearchToolConfig(),
@@ -350,7 +351,7 @@ class TestMCPPassThroughOAuth:
         tool_dict = construct_tools(
             persona=persona,
             db_session=db_session,
-            emitter=get_default_emitter(),
+            emitter=Emitter(merged_queue=queue.Queue()),
             user=user,
             llm=llm,
             search_tool_config=SearchToolConfig(),
@@ -458,7 +459,7 @@ class TestMCPPassThroughOAuth:
         tool_dict = construct_tools(
             persona=persona,
             db_session=db_session,
-            emitter=get_default_emitter(),
+            emitter=Emitter(merged_queue=queue.Queue()),
             user=user,
             llm=llm,
             search_tool_config=SearchToolConfig(),
@@ -541,7 +542,7 @@ class TestMCPPassThroughOAuth:
         tool_dict = construct_tools(
             persona=persona,
             db_session=db_session,
-            emitter=get_default_emitter(),
+            emitter=Emitter(merged_queue=queue.Queue()),
             user=user,
             llm=llm,
             search_tool_config=SearchToolConfig(),

backend/tests/external_dependency_unit/tools/test_oauth_tool_integration.py

@@ -8,6 +8,7 @@ Tests the priority logic for OAuth tokens when constructing custom tools:
 All external HTTP calls are mocked, but Postgres and Redis are running.
 """
 
+import queue
 from typing import Any
 from unittest.mock import Mock
 from unittest.mock import patch
@@ -16,7 +17,7 @@ from uuid import uuid4
 import pytest
 from sqlalchemy.orm import Session
 
-from onyx.chat.emitter import get_default_emitter
+from onyx.chat.emitter import Emitter
 from onyx.db.models import OAuthAccount
 from onyx.db.models import OAuthConfig
 from onyx.db.models import Persona
@@ -174,7 +175,7 @@ class TestOAuthToolIntegrationPriority:
         tool_dict = construct_tools(
             persona=persona,
             db_session=db_session,
-            emitter=get_default_emitter(),
+            emitter=Emitter(merged_queue=queue.Queue()),
             user=user,
             llm=llm,
             search_tool_config=search_tool_config,
@@ -232,7 +233,7 @@ class TestOAuthToolIntegrationPriority:
         tool_dict = construct_tools(
             persona=persona,
             db_session=db_session,
-            emitter=get_default_emitter(),
+            emitter=Emitter(merged_queue=queue.Queue()),
             user=user,
             llm=llm,
         )
@@ -284,7 +285,7 @@ class TestOAuthToolIntegrationPriority:
             tool_dict = construct_tools(
                 persona=persona,
                 db_session=db_session,
-                emitter=get_default_emitter(),
+                emitter=Emitter(merged_queue=queue.Queue()),
                 user=user,
                 llm=llm,
             )
@@ -345,7 +346,7 @@ class TestOAuthToolIntegrationPriority:
         tool_dict = construct_tools(
             persona=persona,
             db_session=db_session,
-            emitter=get_default_emitter(),
+            emitter=Emitter(merged_queue=queue.Queue()),
             user=user,
             llm=llm,
         )
@@ -416,7 +417,7 @@ class TestOAuthToolIntegrationPriority:
             tool_dict = construct_tools(
                 persona=persona,
                 db_session=db_session,
-                emitter=get_default_emitter(),
+                emitter=Emitter(merged_queue=queue.Queue()),
                 user=user,
                 llm=llm,
             )
@@ -483,7 +484,7 @@ class TestOAuthToolIntegrationPriority:
         tool_dict = construct_tools(
             persona=persona,
             db_session=db_session,
-            emitter=get_default_emitter(),
+            emitter=Emitter(merged_queue=queue.Queue()),
             user=user,
             llm=llm,
         )
@@ -536,7 +537,7 @@ class TestOAuthToolIntegrationPriority:
         tool_dict = construct_tools(
             persona=persona,
             db_session=db_session,
-            emitter=get_default_emitter(),
+            emitter=Emitter(merged_queue=queue.Queue()),
             user=user,
             llm=llm,
         )

backend/tests/unit/onyx/chat/test_emitter.py

@@ -0,0 +1,173 @@
+"""Unit tests for the Emitter class.
+
+All tests use the streaming mode (merged_queue required). Emitter has a single
+code path — no standalone bus.
+"""
+
+import queue
+
+from onyx.chat.emitter import Emitter
+from onyx.server.query_and_chat.placement import Placement
+from onyx.server.query_and_chat.streaming_models import OverallStop
+from onyx.server.query_and_chat.streaming_models import Packet
+from onyx.server.query_and_chat.streaming_models import ReasoningStart
+
+
+# ---------------------------------------------------------------------------
+# Helpers
+# ---------------------------------------------------------------------------
+
+
+def _placement(
+    turn_index: int = 0,
+    tab_index: int = 0,
+    sub_turn_index: int | None = None,
+) -> Placement:
+    return Placement(
+        turn_index=turn_index,
+        tab_index=tab_index,
+        sub_turn_index=sub_turn_index,
+    )
+
+
+def _packet(
+    turn_index: int = 0,
+    tab_index: int = 0,
+    sub_turn_index: int | None = None,
+) -> Packet:
+    """Build a minimal valid packet with an OverallStop payload."""
+    return Packet(
+        placement=_placement(turn_index, tab_index, sub_turn_index),
+        obj=OverallStop(stop_reason="test"),
+    )
+
+
+def _make_emitter(model_idx: int = 0) -> tuple["Emitter", "queue.Queue"]:
+    """Return (emitter, queue) wired together."""
+    mq: queue.Queue = queue.Queue()
+    return Emitter(merged_queue=mq, model_idx=model_idx), mq
+
+
+# ---------------------------------------------------------------------------
+# Queue routing
+# ---------------------------------------------------------------------------
+
+
+class TestEmitterQueueRouting:
+    def test_emit_lands_on_merged_queue(self) -> None:
+        emitter, mq = _make_emitter()
+        emitter.emit(_packet())
+        assert not mq.empty()
+
+    def test_queue_item_is_tuple_of_key_and_packet(self) -> None:
+        emitter, mq = _make_emitter(model_idx=1)
+        emitter.emit(_packet())
+        item = mq.get_nowait()
+        assert isinstance(item, tuple)
+        assert len(item) == 2
+
+    def test_multiple_packets_delivered_fifo(self) -> None:
+        emitter, mq = _make_emitter()
+        p1 = _packet(turn_index=0)
+        p2 = _packet(turn_index=1)
+        emitter.emit(p1)
+        emitter.emit(p2)
+        _, t1 = mq.get_nowait()
+        _, t2 = mq.get_nowait()
+        assert t1.placement.turn_index == 0
+        assert t2.placement.turn_index == 1
+
+
+# ---------------------------------------------------------------------------
+# model_index tagging
+# ---------------------------------------------------------------------------
+
+
+class TestEmitterModelIndexTagging:
+    def test_n1_default_model_idx_tags_model_index_zero(self) -> None:
+        """N=1: default model_idx=0, so packet gets model_index=0."""
+        emitter, mq = _make_emitter(model_idx=0)
+        emitter.emit(_packet())
+        _key, tagged = mq.get_nowait()
+        assert tagged.placement.model_index == 0
+
+    def test_model_idx_one_tags_packet(self) -> None:
+        emitter, mq = _make_emitter(model_idx=1)
+        emitter.emit(_packet())
+        _key, tagged = mq.get_nowait()
+        assert tagged.placement.model_index == 1
+
+    def test_model_idx_two_tags_packet(self) -> None:
+        """Boundary: third model in a 3-model run."""
+        emitter, mq = _make_emitter(model_idx=2)
+        emitter.emit(_packet())
+        _key, tagged = mq.get_nowait()
+        assert tagged.placement.model_index == 2
+
+
+# ---------------------------------------------------------------------------
+# Queue key
+# ---------------------------------------------------------------------------
+
+
+class TestEmitterQueueKey:
+    def test_key_equals_model_idx(self) -> None:
+        """Drain loop uses the key to route packets; it must match model_idx."""
+        emitter, mq = _make_emitter(model_idx=2)
+        emitter.emit(_packet())
+        key, _ = mq.get_nowait()
+        assert key == 2
+
+    def test_n1_key_is_zero(self) -> None:
+        emitter, mq = _make_emitter(model_idx=0)
+        emitter.emit(_packet())
+        key, _ = mq.get_nowait()
+        assert key == 0
+
+
+# ---------------------------------------------------------------------------
+# Placement field preservation
+# ---------------------------------------------------------------------------
+
+
+class TestEmitterPlacementPreservation:
+    def test_turn_index_is_preserved(self) -> None:
+        emitter, mq = _make_emitter()
+        emitter.emit(_packet(turn_index=5))
+        _, tagged = mq.get_nowait()
+        assert tagged.placement.turn_index == 5
+
+    def test_tab_index_is_preserved(self) -> None:
+        emitter, mq = _make_emitter()
+        emitter.emit(_packet(tab_index=3))
+        _, tagged = mq.get_nowait()
+        assert tagged.placement.tab_index == 3
+
+    def test_sub_turn_index_is_preserved(self) -> None:
+        emitter, mq = _make_emitter()
+        emitter.emit(_packet(sub_turn_index=2))
+        _, tagged = mq.get_nowait()
+        assert tagged.placement.sub_turn_index == 2
+
+    def test_sub_turn_index_none_is_preserved(self) -> None:
+        emitter, mq = _make_emitter()
+        emitter.emit(_packet(sub_turn_index=None))
+        _, tagged = mq.get_nowait()
+        assert tagged.placement.sub_turn_index is None
+
+    def test_packet_obj_is_not_modified(self) -> None:
+        """The payload object must survive tagging untouched."""
+        emitter, mq = _make_emitter()
+        original_obj = OverallStop(stop_reason="sentinel")
+        pkt = Packet(placement=_placement(), obj=original_obj)
+        emitter.emit(pkt)
+        _, tagged = mq.get_nowait()
+        assert tagged.obj is original_obj
+
+    def test_different_obj_types_are_handled(self) -> None:
+        """Any valid PacketObj type passes through correctly."""
+        emitter, mq = _make_emitter()
+        pkt = Packet(placement=_placement(), obj=ReasoningStart())
+        emitter.emit(pkt)
+        _, tagged = mq.get_nowait()
+        assert isinstance(tagged.obj, ReasoningStart)

backend/tests/unit/onyx/chat/test_multi_model_streaming.py

@@ -0,0 +1,676 @@
+"""Unit tests for multi-model streaming validation and DB helpers.
+
+These are pure unit tests — no real database or LLM calls required.
+The validation logic in handle_multi_model_stream fires before any external
+calls, so we can trigger it with lightweight mocks.
+"""
+
+import time
+from collections.abc import Generator
+from typing import Any
+from typing import cast
+from unittest.mock import MagicMock
+from unittest.mock import patch
+from uuid import uuid4
+
+import pytest
+
+from onyx.chat.models import StreamingError
+from onyx.configs.constants import MessageType
+from onyx.db.chat import set_preferred_response
+from onyx.llm.override_models import LLMOverride
+from onyx.server.query_and_chat.models import SendMessageRequest
+from onyx.server.query_and_chat.placement import Placement
+from onyx.server.query_and_chat.streaming_models import OverallStop
+from onyx.server.query_and_chat.streaming_models import Packet
+from onyx.server.query_and_chat.streaming_models import ReasoningStart
+from onyx.utils.variable_functionality import global_version
+
+
+@pytest.fixture(autouse=True)
+def _restore_ee_version() -> Generator[None, None, None]:
+    """Reset EE global state after each test.
+
+    Importing onyx.chat.process_message triggers set_is_ee_based_on_env_variable()
+    (via the celery client import chain).  Without this fixture, the EE flag stays
+    True for the rest of the session and breaks unrelated tests that mock Confluence
+    or other connectors and assume EE is disabled.
+    """
+    original = global_version._is_ee
+    yield
+    global_version._is_ee = original
+
+
+# ---------------------------------------------------------------------------
+# Helpers
+# ---------------------------------------------------------------------------
+
+
+def _make_request(**kwargs: Any) -> SendMessageRequest:
+    defaults: dict[str, Any] = {
+        "message": "hello",
+        "chat_session_id": uuid4(),
+    }
+    defaults.update(kwargs)
+    return SendMessageRequest(**defaults)
+
+
+def _make_override(provider: str = "openai", version: str = "gpt-4") -> LLMOverride:
+    return LLMOverride(model_provider=provider, model_version=version)
+
+
+def _first_from_stream(req: SendMessageRequest, overrides: list[LLMOverride]) -> Any:
+    """Return the first item yielded by handle_multi_model_stream."""
+    from onyx.chat.process_message import handle_multi_model_stream
+
+    user = MagicMock()
+    user.is_anonymous = False
+    user.email = "test@example.com"
+    db = MagicMock()
+
+    gen = handle_multi_model_stream(req, user, db, overrides)
+    return next(gen)
+
+
+# ---------------------------------------------------------------------------
+# handle_multi_model_stream — validation
+# ---------------------------------------------------------------------------
+
+
+class TestRunMultiModelStreamValidation:
+    def test_single_override_yields_error(self) -> None:
+        """Exactly 1 override is not multi-model — yields StreamingError."""
+        req = _make_request()
+        result = _first_from_stream(req, [_make_override()])
+        assert isinstance(result, StreamingError)
+        assert "2-3" in result.error
+
+    def test_four_overrides_yields_error(self) -> None:
+        """4 overrides exceeds maximum — yields StreamingError."""
+        req = _make_request()
+        result = _first_from_stream(
+            req,
+            [
+                _make_override("openai", "gpt-4"),
+                _make_override("anthropic", "claude-3"),
+                _make_override("google", "gemini-pro"),
+                _make_override("cohere", "command-r"),
+            ],
+        )
+        assert isinstance(result, StreamingError)
+        assert "2-3" in result.error
+
+    def test_zero_overrides_yields_error(self) -> None:
+        """Empty override list yields StreamingError."""
+        req = _make_request()
+        result = _first_from_stream(req, [])
+        assert isinstance(result, StreamingError)
+        assert "2-3" in result.error
+
+    def test_deep_research_yields_error(self) -> None:
+        """deep_research=True is incompatible with multi-model — yields StreamingError."""
+        req = _make_request(deep_research=True)
+        result = _first_from_stream(
+            req, [_make_override(), _make_override("anthropic", "claude-3")]
+        )
+        assert isinstance(result, StreamingError)
+        assert "not supported" in result.error
+
+    def test_exactly_two_overrides_is_minimum(self) -> None:
+        """Boundary: 1 override yields error, 2 overrides passes validation."""
+        req = _make_request()
+        # 1 override must yield a StreamingError
+        result = _first_from_stream(req, [_make_override()])
+        assert isinstance(
+            result, StreamingError
+        ), "1 override should yield StreamingError"
+        # 2 overrides must NOT yield a validation StreamingError (may raise later due to
+        # missing session, that's OK — validation itself passed)
+        try:
+            result2 = _first_from_stream(
+                req, [_make_override(), _make_override("anthropic", "claude-3")]
+            )
+            if isinstance(result2, StreamingError) and "2-3" in result2.error:
+                pytest.fail(
+                    f"2 overrides should pass validation, got StreamingError: {result2.error}"
+                )
+        except Exception:
+            pass  # Any non-validation error means validation passed
+
+
+# ---------------------------------------------------------------------------
+# set_preferred_response — validation (mocked db)
+# ---------------------------------------------------------------------------
+
+
+class TestSetPreferredResponseValidation:
+    def test_user_message_not_found(self) -> None:
+        db = MagicMock()
+        db.get.return_value = None
+
+        with pytest.raises(ValueError, match="not found"):
+            set_preferred_response(
+                db, user_message_id=999, preferred_assistant_message_id=1
+            )
+
+    def test_wrong_message_type(self) -> None:
+        """Cannot set preferred response on a non-USER message."""
+        db = MagicMock()
+        user_msg = MagicMock()
+        user_msg.message_type = MessageType.ASSISTANT  # wrong type
+
+        db.get.return_value = user_msg
+
+        with pytest.raises(ValueError, match="not a user message"):
+            set_preferred_response(
+                db, user_message_id=1, preferred_assistant_message_id=2
+            )
+
+    def test_assistant_message_not_found(self) -> None:
+        db = MagicMock()
+        user_msg = MagicMock()
+        user_msg.message_type = MessageType.USER
+
+        # First call returns user_msg, second call (for assistant) returns None
+        db.get.side_effect = [user_msg, None]
+
+        with pytest.raises(ValueError, match="not found"):
+            set_preferred_response(
+                db, user_message_id=1, preferred_assistant_message_id=2
+            )
+
+    def test_assistant_not_child_of_user(self) -> None:
+        db = MagicMock()
+        user_msg = MagicMock()
+        user_msg.message_type = MessageType.USER
+
+        assistant_msg = MagicMock()
+        assistant_msg.parent_message_id = 999  # different parent
+
+        db.get.side_effect = [user_msg, assistant_msg]
+
+        with pytest.raises(ValueError, match="not a child"):
+            set_preferred_response(
+                db, user_message_id=1, preferred_assistant_message_id=2
+            )
+
+    def test_valid_call_sets_preferred_response_id(self) -> None:
+        db = MagicMock()
+        user_msg = MagicMock()
+        user_msg.message_type = MessageType.USER
+
+        assistant_msg = MagicMock()
+        assistant_msg.parent_message_id = 1  # correct parent
+
+        db.get.side_effect = [user_msg, assistant_msg]
+
+        set_preferred_response(db, user_message_id=1, preferred_assistant_message_id=2)
+
+        assert user_msg.preferred_response_id == 2
+        assert user_msg.latest_child_message_id == 2
+
+
+# ---------------------------------------------------------------------------
+# LLMOverride — display_name field
+# ---------------------------------------------------------------------------
+
+
+class TestLLMOverrideDisplayName:
+    def test_display_name_defaults_none(self) -> None:
+        override = LLMOverride(model_provider="openai", model_version="gpt-4")
+        assert override.display_name is None
+
+    def test_display_name_set(self) -> None:
+        override = LLMOverride(
+            model_provider="openai",
+            model_version="gpt-4",
+            display_name="GPT-4 Turbo",
+        )
+        assert override.display_name == "GPT-4 Turbo"
+
+    def test_display_name_serializes(self) -> None:
+        override = LLMOverride(
+            model_provider="anthropic",
+            model_version="claude-opus-4-6",
+            display_name="Claude Opus",
+        )
+        d = override.model_dump()
+        assert d["display_name"] == "Claude Opus"
+
+
+# ---------------------------------------------------------------------------
+# _run_models — drain loop behaviour
+# ---------------------------------------------------------------------------
+
+
+def _make_setup(n_models: int = 1) -> MagicMock:
+    """Minimal ChatTurnSetup mock whose fields pass Pydantic validation in _run_model."""
+    setup = MagicMock()
+    setup.llms = [MagicMock() for _ in range(n_models)]
+    setup.model_display_names = [f"model-{i}" for i in range(n_models)]
+    setup.check_is_connected = MagicMock(return_value=True)
+    setup.reserved_messages = [MagicMock() for _ in range(n_models)]
+    setup.reserved_token_count = 100
+    # Fields consumed by SearchToolConfig / CustomToolConfig / FileReaderToolConfig
+    # constructors inside _run_model — must be typed correctly for Pydantic.
+    setup.new_msg_req.deep_research = False
+    setup.new_msg_req.internal_search_filters = None
+    setup.new_msg_req.allowed_tool_ids = None
+    setup.new_msg_req.include_citations = True
+    setup.search_params.project_id_filter = None
+    setup.search_params.persona_id_filter = None
+    setup.bypass_acl = False
+    setup.slack_context = None
+    setup.available_files.user_file_ids = []
+    setup.available_files.chat_file_ids = []
+    setup.forced_tool_id = None
+    setup.simple_chat_history = []
+    setup.chat_session.id = uuid4()
+    setup.user_message.id = None
+    setup.custom_tool_additional_headers = None
+    setup.mcp_headers = None
+    return setup
+
+
+_RUN_MODELS_PATCHES = [
+    patch("onyx.chat.process_message.run_llm_loop"),
+    patch("onyx.chat.process_message.run_deep_research_llm_loop"),
+    patch("onyx.chat.process_message.construct_tools", return_value={}),
+    patch("onyx.chat.process_message.get_session_with_current_tenant"),
+    patch("onyx.chat.process_message.llm_loop_completion_handle"),
+    patch("onyx.chat.process_message.get_llm_token_counter", return_value=lambda _: 0),
+]
+
+
+def _run_models_collect(setup: MagicMock) -> list:
+    """Drive _run_models to completion and return all yielded items."""
+    from onyx.chat.process_message import _run_models
+
+    return list(_run_models(setup, MagicMock(), MagicMock()))
+
+
+class TestRunModels:
+    """Tests for the _run_models worker-thread drain loop.
+
+    All external dependencies (LLM, DB, tools) are patched out.  Worker threads
+    still run but return immediately since run_llm_loop is mocked.
+    """
+
+    def test_n1_overall_stop_from_llm_loop_passes_through(self) -> None:
+        """OverallStop emitted by run_llm_loop is passed through the drain loop unchanged."""
+
+        def emit_stop(**kwargs: Any) -> None:
+            kwargs["emitter"].emit(
+                Packet(
+                    placement=Placement(turn_index=0),
+                    obj=OverallStop(stop_reason="complete"),
+                )
+            )
+
+        with (
+            patch("onyx.chat.process_message.run_llm_loop", side_effect=emit_stop),
+            patch("onyx.chat.process_message.run_deep_research_llm_loop"),
+            patch("onyx.chat.process_message.construct_tools", return_value={}),
+            patch("onyx.chat.process_message.get_session_with_current_tenant"),
+            patch("onyx.chat.process_message.llm_loop_completion_handle"),
+            patch(
+                "onyx.chat.process_message.get_llm_token_counter",
+                return_value=lambda _: 0,
+            ),
+        ):
+            packets = _run_models_collect(_make_setup(n_models=1))
+
+        stops = [
+            p
+            for p in packets
+            if isinstance(p, Packet) and isinstance(p.obj, OverallStop)
+        ]
+        assert len(stops) == 1
+        stop_obj = stops[0].obj
+        assert isinstance(stop_obj, OverallStop)
+        assert stop_obj.stop_reason == "complete"
+
+    def test_n1_emitted_packet_has_model_index_zero(self) -> None:
+        """Single-model path: model_index is 0 (Emitter defaults model_idx=0)."""
+
+        def emit_one(**kwargs: Any) -> None:
+            kwargs["emitter"].emit(
+                Packet(placement=Placement(turn_index=0), obj=ReasoningStart())
+            )
+
+        with (
+            patch("onyx.chat.process_message.run_llm_loop", side_effect=emit_one),
+            patch("onyx.chat.process_message.run_deep_research_llm_loop"),
+            patch("onyx.chat.process_message.construct_tools", return_value={}),
+            patch("onyx.chat.process_message.get_session_with_current_tenant"),
+            patch("onyx.chat.process_message.llm_loop_completion_handle"),
+            patch(
+                "onyx.chat.process_message.get_llm_token_counter",
+                return_value=lambda _: 0,
+            ),
+        ):
+            packets = _run_models_collect(_make_setup(n_models=1))
+
+        reasoning = [
+            p
+            for p in packets
+            if isinstance(p, Packet) and isinstance(p.obj, ReasoningStart)
+        ]
+        assert len(reasoning) == 1
+        assert reasoning[0].placement.model_index == 0
+
+    def test_n2_each_model_packet_tagged_with_its_index(self) -> None:
+        """Multi-model path: packets from model 0 get index=0, model 1 gets index=1."""
+
+        def emit_one(**kwargs: Any) -> None:
+            # _model_idx is set by _run_model based on position in setup.llms
+            emitter = kwargs["emitter"]
+            emitter.emit(
+                Packet(placement=Placement(turn_index=0), obj=ReasoningStart())
+            )
+
+        with (
+            patch("onyx.chat.process_message.run_llm_loop", side_effect=emit_one),
+            patch("onyx.chat.process_message.run_deep_research_llm_loop"),
+            patch("onyx.chat.process_message.construct_tools", return_value={}),
+            patch("onyx.chat.process_message.get_session_with_current_tenant"),
+            patch("onyx.chat.process_message.llm_loop_completion_handle"),
+            patch(
+                "onyx.chat.process_message.get_llm_token_counter",
+                return_value=lambda _: 0,
+            ),
+        ):
+            packets = _run_models_collect(_make_setup(n_models=2))
+
+        reasoning = [
+            p
+            for p in packets
+            if isinstance(p, Packet) and isinstance(p.obj, ReasoningStart)
+        ]
+        assert len(reasoning) == 2
+        indices = {p.placement.model_index for p in reasoning}
+        assert indices == {0, 1}
+
+    def test_model_error_yields_streaming_error(self) -> None:
+        """An exception inside a worker thread is surfaced as a StreamingError."""
+
+        def always_fail(**_kwargs: Any) -> None:
+            raise RuntimeError("intentional test failure")
+
+        with (
+            patch("onyx.chat.process_message.run_llm_loop", side_effect=always_fail),
+            patch("onyx.chat.process_message.run_deep_research_llm_loop"),
+            patch("onyx.chat.process_message.construct_tools", return_value={}),
+            patch("onyx.chat.process_message.get_session_with_current_tenant"),
+            patch("onyx.chat.process_message.llm_loop_completion_handle"),
+            patch(
+                "onyx.chat.process_message.get_llm_token_counter",
+                return_value=lambda _: 0,
+            ),
+        ):
+            packets = _run_models_collect(_make_setup(n_models=1))
+
+        errors = [p for p in packets if isinstance(p, StreamingError)]
+        assert len(errors) == 1
+        assert errors[0].error_code == "MODEL_ERROR"
+        assert "intentional test failure" in errors[0].error
+
+    def test_one_model_error_does_not_stop_other_models(self) -> None:
+        """A failing model yields StreamingError; the surviving model's packets still arrive."""
+
+        def fail_model_0_succeed_model_1(**kwargs: Any) -> None:
+            emitter = kwargs["emitter"]
+            # _model_idx is always int (0 for N=1, 0/1/2… for N>1)
+            if emitter._model_idx == 0:
+                raise RuntimeError("model 0 failed")
+            emitter.emit(
+                Packet(placement=Placement(turn_index=0), obj=ReasoningStart())
+            )
+
+        with (
+            patch(
+                "onyx.chat.process_message.run_llm_loop",
+                side_effect=fail_model_0_succeed_model_1,
+            ),
+            patch("onyx.chat.process_message.run_deep_research_llm_loop"),
+            patch("onyx.chat.process_message.construct_tools", return_value={}),
+            patch("onyx.chat.process_message.get_session_with_current_tenant"),
+            patch("onyx.chat.process_message.llm_loop_completion_handle"),
+            patch(
+                "onyx.chat.process_message.get_llm_token_counter",
+                return_value=lambda _: 0,
+            ),
+        ):
+            packets = _run_models_collect(_make_setup(n_models=2))
+
+        errors = [p for p in packets if isinstance(p, StreamingError)]
+        assert len(errors) == 1
+
+        reasoning = [
+            p
+            for p in packets
+            if isinstance(p, Packet) and isinstance(p.obj, ReasoningStart)
+        ]
+        assert len(reasoning) == 1
+        assert reasoning[0].placement.model_index == 1
+
+    def test_cancellation_yields_user_cancelled_stop(self) -> None:
+        """If check_is_connected returns False, drain loop emits user_cancelled."""
+
+        def slow_llm(**_kwargs: Any) -> None:
+            time.sleep(0.3)  # Outlasts the 50 ms queue-poll interval
+
+        setup = _make_setup(n_models=1)
+        setup.check_is_connected = MagicMock(return_value=False)
+
+        with (
+            patch("onyx.chat.process_message.run_llm_loop", side_effect=slow_llm),
+            patch("onyx.chat.process_message.run_deep_research_llm_loop"),
+            patch("onyx.chat.process_message.construct_tools", return_value={}),
+            patch("onyx.chat.process_message.get_session_with_current_tenant"),
+            patch("onyx.chat.process_message.llm_loop_completion_handle"),
+            patch(
+                "onyx.chat.process_message.get_llm_token_counter",
+                return_value=lambda _: 0,
+            ),
+        ):
+            packets = _run_models_collect(setup)
+
+        stops = [
+            p
+            for p in packets
+            if isinstance(p, Packet) and isinstance(p.obj, OverallStop)
+        ]
+        assert any(
+            isinstance(s.obj, OverallStop) and s.obj.stop_reason == "user_cancelled"
+            for s in stops
+        )
+
+    def test_completion_handle_called_on_disconnect(self) -> None:
+        """llm_loop_completion_handle must still be called even when user disconnects.
+
+        Regression test for the disconnect-cleanup bug: the old
+        run_chat_loop_with_state_containers always called completion_callback in
+        its finally block (even on disconnect) so the DB message was updated from
+        the TERMINATED placeholder to a partial answer.  The new _run_models must
+        replicate this — otherwise the integration test
+        test_send_message_disconnect_and_cleanup fails because the message stays
+        as "Response was terminated prior to completion, try regenerating."
+        """
+
+        def slow_llm(**_kwargs: Any) -> None:
+            time.sleep(0.3)
+
+        setup = _make_setup(n_models=2)
+        setup.check_is_connected = MagicMock(return_value=False)
+
+        with (
+            patch("onyx.chat.process_message.run_llm_loop", side_effect=slow_llm),
+            patch("onyx.chat.process_message.run_deep_research_llm_loop"),
+            patch("onyx.chat.process_message.construct_tools", return_value={}),
+            patch("onyx.chat.process_message.get_session_with_current_tenant"),
+            patch(
+                "onyx.chat.process_message.llm_loop_completion_handle"
+            ) as mock_handle,
+            patch(
+                "onyx.chat.process_message.get_llm_token_counter",
+                return_value=lambda _: 0,
+            ),
+        ):
+            _run_models_collect(setup)
+
+        # Must be called once per model, not zero times
+        assert mock_handle.call_count == 2
+
+    def test_completion_handle_called_for_each_successful_model(self) -> None:
+        """llm_loop_completion_handle must be called once per model that succeeded."""
+        setup = _make_setup(n_models=2)
+
+        with (
+            patch("onyx.chat.process_message.run_llm_loop"),
+            patch("onyx.chat.process_message.run_deep_research_llm_loop"),
+            patch("onyx.chat.process_message.construct_tools", return_value={}),
+            patch("onyx.chat.process_message.get_session_with_current_tenant"),
+            patch(
+                "onyx.chat.process_message.llm_loop_completion_handle"
+            ) as mock_handle,
+            patch(
+                "onyx.chat.process_message.get_llm_token_counter",
+                return_value=lambda _: 0,
+            ),
+        ):
+            _run_models_collect(setup)
+
+        assert mock_handle.call_count == 2
+
+    def test_completion_handle_not_called_for_failed_model(self) -> None:
+        """llm_loop_completion_handle must be skipped for a model that raised."""
+
+        def always_fail(**_kwargs: Any) -> None:
+            raise RuntimeError("fail")
+
+        with (
+            patch("onyx.chat.process_message.run_llm_loop", side_effect=always_fail),
+            patch("onyx.chat.process_message.run_deep_research_llm_loop"),
+            patch("onyx.chat.process_message.construct_tools", return_value={}),
+            patch("onyx.chat.process_message.get_session_with_current_tenant"),
+            patch(
+                "onyx.chat.process_message.llm_loop_completion_handle"
+            ) as mock_handle,
+            patch(
+                "onyx.chat.process_message.get_llm_token_counter",
+                return_value=lambda _: 0,
+            ),
+        ):
+            _run_models_collect(_make_setup(n_models=1))
+
+        mock_handle.assert_not_called()
+
+    def test_http_disconnect_completion_via_generator_exit(self) -> None:
+        """GeneratorExit from HTTP disconnect triggers worker self-completion.
+
+        When the HTTP client closes the connection, Starlette throws GeneratorExit
+        into the stream generator. The finally block sets drain_done (signalling
+        emitters to stop blocking) and calls executor.shutdown(wait=False) so the
+        server thread is never blocked. Worker threads detect drain_done.is_set()
+        after run_llm_loop completes and self-persist the result via
+        llm_loop_completion_handle using their own DB session.
+
+        This is the primary regression for test_send_message_disconnect_and_cleanup:
+        the integration test disconnects mid-stream and expects the DB message to be
+        updated from the TERMINATED placeholder to the real response.
+        """
+        import threading
+
+        # Signals the worker to unblock from run_llm_loop after gen.close() returns.
+        # This guarantees drain_done is set BEFORE the worker returns from run_llm_loop,
+        # so the self-completion path (drain_done.is_set() check) is always taken.
+        disconnect_received = threading.Event()
+        # Set by the llm_loop_completion_handle mock when called.
+        completion_called = threading.Event()
+
+        def emit_then_complete(**kwargs: Any) -> None:
+            """Emit one packet (to give the drain loop a yield point), then block
+            until the main thread signals that gen.close() has been called.  This
+            ensures drain_done is set before we return so model_succeeded is checked
+            against a set drain_done — no race condition.
+            """
+            emitter = kwargs["emitter"]
+            emitter.emit(
+                Packet(placement=Placement(turn_index=0), obj=ReasoningStart())
+            )
+            disconnect_received.wait(timeout=5)
+
+        setup = _make_setup(n_models=1)
+        # is_connected() always True — HTTP disconnect does NOT set the Redis stop fence.
+        setup.check_is_connected = MagicMock(return_value=True)
+
+        with (
+            patch(
+                "onyx.chat.process_message.run_llm_loop",
+                side_effect=emit_then_complete,
+            ),
+            patch("onyx.chat.process_message.run_deep_research_llm_loop"),
+            patch("onyx.chat.process_message.construct_tools", return_value={}),
+            patch("onyx.chat.process_message.get_session_with_current_tenant"),
+            patch(
+                "onyx.chat.process_message.llm_loop_completion_handle",
+                side_effect=lambda *_, **__: completion_called.set(),
+            ) as mock_handle,
+            patch(
+                "onyx.chat.process_message.get_llm_token_counter",
+                return_value=lambda _: 0,
+            ),
+        ):
+            from onyx.chat.process_message import _run_models
+
+            # cast to Generator so .close() is available; _run_models returns
+            # AnswerStream (= Iterator) but the actual object is always a generator.
+            gen = cast(Generator, _run_models(setup, MagicMock(), MagicMock()))
+            # Advance to the first yielded packet — generator suspends at `yield item`.
+            first = next(gen)
+            assert isinstance(first, Packet)
+            # Simulate Starlette closing the stream on HTTP client disconnect.
+            # GeneratorExit is thrown at the `yield item` suspension point.
+            gen.close()
+            # Unblock the worker now that drain_done has been set by gen.close().
+            disconnect_received.set()
+
+            # Worker self-completes asynchronously (executor.shutdown(wait=False)).
+            # Wait here, inside the patch context, so that get_session_with_current_tenant
+            # and llm_loop_completion_handle mocks are still active when the worker calls them.
+            assert completion_called.wait(
+                timeout=5
+            ), "worker must self-complete via drain_done within 5 seconds"
+            assert (
+                mock_handle.call_count == 1
+            ), "completion handle must be called once for the successful model"
+
+    def test_external_state_container_used_for_model_zero(self) -> None:
+        """When provided, external_state_container is used as state_containers[0]."""
+        from onyx.chat.chat_state import ChatStateContainer
+        from onyx.chat.process_message import _run_models
+
+        external = ChatStateContainer()
+        setup = _make_setup(n_models=1)
+
+        with (
+            patch("onyx.chat.process_message.run_llm_loop") as mock_llm,
+            patch("onyx.chat.process_message.run_deep_research_llm_loop"),
+            patch("onyx.chat.process_message.construct_tools", return_value={}),
+            patch("onyx.chat.process_message.get_session_with_current_tenant"),
+            patch("onyx.chat.process_message.llm_loop_completion_handle"),
+            patch(
+                "onyx.chat.process_message.get_llm_token_counter",
+                return_value=lambda _: 0,
+            ),
+        ):
+            list(
+                _run_models(
+                    setup, MagicMock(), MagicMock(), external_state_container=external
+                )
+            )
+
+        # The state_container kwarg passed to run_llm_loop must be the external one
+        call_kwargs = mock_llm.call_args.kwargs
+        assert call_kwargs["state_container"] is external

backend/tests/unit/onyx/document_index/opensearch/test_opensearch_batch_flush.py

@@ -0,0 +1,223 @@
+from unittest.mock import MagicMock
+from unittest.mock import patch
+
+from onyx.access.models import DocumentAccess
+from onyx.configs.constants import DocumentSource
+from onyx.connectors.models import Document
+from onyx.connectors.models import TextSection
+from onyx.document_index.interfaces_new import IndexingMetadata
+from onyx.document_index.interfaces_new import TenantState
+from onyx.document_index.opensearch.opensearch_document_index import (
+    OpenSearchDocumentIndex,
+)
+from onyx.indexing.models import ChunkEmbedding
+from onyx.indexing.models import DocMetadataAwareIndexChunk
+
+
+def _make_chunk(
+    doc_id: str,
+    chunk_id: int,
+) -> DocMetadataAwareIndexChunk:
+    """Creates a minimal DocMetadataAwareIndexChunk for testing."""
+    doc = Document(
+        id=doc_id,
+        sections=[TextSection(text="test", link="http://test.com")],
+        source=DocumentSource.FILE,
+        semantic_identifier="test_doc",
+        metadata={},
+    )
+    access = DocumentAccess.build(
+        user_emails=[],
+        user_groups=[],
+        external_user_emails=[],
+        external_user_group_ids=[],
+        is_public=True,
+    )
+    return DocMetadataAwareIndexChunk(
+        chunk_id=chunk_id,
+        blurb="test",
+        content="test content",
+        source_links={0: "http://test.com"},
+        image_file_id=None,
+        section_continuation=False,
+        source_document=doc,
+        title_prefix="",
+        metadata_suffix_semantic="",
+        metadata_suffix_keyword="",
+        mini_chunk_texts=None,
+        large_chunk_id=None,
+        doc_summary="",
+        chunk_context="",
+        contextual_rag_reserved_tokens=0,
+        embeddings=ChunkEmbedding(full_embedding=[0.1] * 10, mini_chunk_embeddings=[]),
+        title_embedding=[0.1] * 10,
+        tenant_id="test_tenant",
+        access=access,
+        document_sets=set(),
+        user_project=[],
+        personas=[],
+        boost=0,
+        aggregated_chunk_boost_factor=1.0,
+        ancestor_hierarchy_node_ids=[],
+    )
+
+
+def _make_index() -> tuple[OpenSearchDocumentIndex, MagicMock]:
+    """Creates an OpenSearchDocumentIndex with a mocked client.
+    Returns the index and the mock for bulk_index_documents."""
+    mock_client = MagicMock()
+    mock_bulk = MagicMock()
+    mock_client.bulk_index_documents = mock_bulk
+
+    tenant_state = TenantState(tenant_id="test_tenant", multitenant=False)
+
+    index = OpenSearchDocumentIndex.__new__(OpenSearchDocumentIndex)
+    index._index_name = "test_index"
+    index._client = mock_client
+    index._tenant_state = tenant_state
+
+    return index, mock_bulk
+
+
+def _make_metadata(doc_id: str, chunk_count: int) -> IndexingMetadata:
+    return IndexingMetadata(
+        doc_id_to_chunk_cnt_diff={
+            doc_id: IndexingMetadata.ChunkCounts(
+                old_chunk_cnt=0,
+                new_chunk_cnt=chunk_count,
+            ),
+        },
+    )
+
+
+@patch(
+    "onyx.document_index.opensearch.opensearch_document_index.MAX_CHUNKS_PER_DOC_BATCH",
+    100,
+)
+def test_single_doc_under_batch_limit_flushes_once() -> None:
+    """A document with fewer chunks than MAX_CHUNKS_PER_DOC_BATCH should flush once."""
+    index, mock_bulk = _make_index()
+    doc_id = "doc_1"
+    num_chunks = 50
+    chunks = [_make_chunk(doc_id, i) for i in range(num_chunks)]
+    metadata = _make_metadata(doc_id, num_chunks)
+
+    with patch.object(index, "delete", return_value=0):
+        index.index(chunks, metadata)
+
+    assert mock_bulk.call_count == 1
+    batch_arg = mock_bulk.call_args_list[0]
+    assert len(batch_arg.kwargs["documents"]) == num_chunks
+
+
+@patch(
+    "onyx.document_index.opensearch.opensearch_document_index.MAX_CHUNKS_PER_DOC_BATCH",
+    100,
+)
+def test_single_doc_over_batch_limit_flushes_multiple_times() -> None:
+    """A document with more chunks than MAX_CHUNKS_PER_DOC_BATCH should flush multiple times."""
+    index, mock_bulk = _make_index()
+    doc_id = "doc_1"
+    num_chunks = 250
+    chunks = [_make_chunk(doc_id, i) for i in range(num_chunks)]
+    metadata = _make_metadata(doc_id, num_chunks)
+
+    with patch.object(index, "delete", return_value=0):
+        index.index(chunks, metadata)
+
+    # 250 chunks / 100 per batch = 3 flushes (100 + 100 + 50)
+    assert mock_bulk.call_count == 3
+    batch_sizes = [len(call.kwargs["documents"]) for call in mock_bulk.call_args_list]
+    assert batch_sizes == [100, 100, 50]
+
+
+@patch(
+    "onyx.document_index.opensearch.opensearch_document_index.MAX_CHUNKS_PER_DOC_BATCH",
+    100,
+)
+def test_single_doc_exactly_at_batch_limit() -> None:
+    """A document with exactly MAX_CHUNKS_PER_DOC_BATCH chunks should flush once
+    (the flush happens on the next chunk, not at the boundary)."""
+    index, mock_bulk = _make_index()
+    doc_id = "doc_1"
+    num_chunks = 100
+    chunks = [_make_chunk(doc_id, i) for i in range(num_chunks)]
+    metadata = _make_metadata(doc_id, num_chunks)
+
+    with patch.object(index, "delete", return_value=0):
+        index.index(chunks, metadata)
+
+    # 100 chunks hit the >= check on chunk 101 which doesn't exist,
+    # so final flush handles all 100
+    # Actually: the elif fires when len(current_chunks) >= 100, which happens
+    # when current_chunks has 100 items and the 101st chunk arrives.
+    # With exactly 100 chunks, the 100th chunk makes len == 99, then appended -> 100.
+    # No 101st chunk arrives, so the final flush handles all 100.
+    assert mock_bulk.call_count == 1
+
+
+@patch(
+    "onyx.document_index.opensearch.opensearch_document_index.MAX_CHUNKS_PER_DOC_BATCH",
+    100,
+)
+def test_single_doc_one_over_batch_limit() -> None:
+    """101 chunks for one doc: first 100 flushed when the 101st arrives, then
+    the 101st is flushed at the end."""
+    index, mock_bulk = _make_index()
+    doc_id = "doc_1"
+    num_chunks = 101
+    chunks = [_make_chunk(doc_id, i) for i in range(num_chunks)]
+    metadata = _make_metadata(doc_id, num_chunks)
+
+    with patch.object(index, "delete", return_value=0):
+        index.index(chunks, metadata)
+
+    assert mock_bulk.call_count == 2
+    batch_sizes = [len(call.kwargs["documents"]) for call in mock_bulk.call_args_list]
+    assert batch_sizes == [100, 1]
+
+
+@patch(
+    "onyx.document_index.opensearch.opensearch_document_index.MAX_CHUNKS_PER_DOC_BATCH",
+    100,
+)
+def test_multiple_docs_each_under_limit_flush_per_doc() -> None:
+    """Multiple documents each under the batch limit should flush once per document."""
+    index, mock_bulk = _make_index()
+    chunks = []
+    for doc_idx in range(3):
+        doc_id = f"doc_{doc_idx}"
+        for chunk_idx in range(50):
+            chunks.append(_make_chunk(doc_id, chunk_idx))
+
+    metadata = IndexingMetadata(
+        doc_id_to_chunk_cnt_diff={
+            f"doc_{i}": IndexingMetadata.ChunkCounts(old_chunk_cnt=0, new_chunk_cnt=50)
+            for i in range(3)
+        },
+    )
+
+    with patch.object(index, "delete", return_value=0):
+        index.index(chunks, metadata)
+
+    # 3 documents = 3 flushes (one per doc boundary + final)
+    assert mock_bulk.call_count == 3
+
+
+@patch(
+    "onyx.document_index.opensearch.opensearch_document_index.MAX_CHUNKS_PER_DOC_BATCH",
+    100,
+)
+def test_delete_called_once_per_document() -> None:
+    """Even with multiple flushes for a single document, delete should only be
+    called once per document."""
+    index, _mock_bulk = _make_index()
+    doc_id = "doc_1"
+    num_chunks = 250
+    chunks = [_make_chunk(doc_id, i) for i in range(num_chunks)]
+    metadata = _make_metadata(doc_id, num_chunks)
+
+    with patch.object(index, "delete", return_value=0) as mock_delete:
+        index.index(chunks, metadata)
+
+    mock_delete.assert_called_once_with(doc_id, None)

backend/tests/unit/onyx/document_index/vespa/test_vespa_batch_flush.py

@@ -0,0 +1,152 @@
+"""Unit tests for VespaDocumentIndex.index().
+
+These tests mock all external I/O (HTTP calls, thread pools) and verify
+the streaming logic, ID cleaning/mapping, and DocumentInsertionRecord
+construction.
+"""
+
+from unittest.mock import MagicMock
+from unittest.mock import patch
+
+from onyx.access.models import DocumentAccess
+from onyx.configs.constants import DocumentSource
+from onyx.connectors.models import Document
+from onyx.connectors.models import TextSection
+from onyx.document_index.interfaces import EnrichedDocumentIndexingInfo
+from onyx.document_index.interfaces_new import IndexingMetadata
+from onyx.document_index.interfaces_new import TenantState
+from onyx.document_index.vespa.vespa_document_index import VespaDocumentIndex
+from onyx.indexing.models import ChunkEmbedding
+from onyx.indexing.models import DocMetadataAwareIndexChunk
+from onyx.indexing.models import IndexChunk
+
+
+def _make_chunk(
+    doc_id: str,
+    chunk_id: int = 0,
+    content: str = "test content",
+) -> DocMetadataAwareIndexChunk:
+    doc = Document(
+        id=doc_id,
+        semantic_identifier="test_doc",
+        sections=[TextSection(text=content, link=None)],
+        source=DocumentSource.NOT_APPLICABLE,
+        metadata={},
+    )
+    index_chunk = IndexChunk(
+        chunk_id=chunk_id,
+        blurb=content[:50],
+        content=content,
+        source_links=None,
+        image_file_id=None,
+        section_continuation=False,
+        source_document=doc,
+        title_prefix="",
+        metadata_suffix_semantic="",
+        metadata_suffix_keyword="",
+        contextual_rag_reserved_tokens=0,
+        doc_summary="",
+        chunk_context="",
+        mini_chunk_texts=None,
+        large_chunk_id=None,
+        embeddings=ChunkEmbedding(
+            full_embedding=[0.1] * 10,
+            mini_chunk_embeddings=[],
+        ),
+        title_embedding=None,
+    )
+    access = DocumentAccess.build(
+        user_emails=[],
+        user_groups=[],
+        external_user_emails=[],
+        external_user_group_ids=[],
+        is_public=True,
+    )
+    return DocMetadataAwareIndexChunk.from_index_chunk(
+        index_chunk=index_chunk,
+        access=access,
+        document_sets=set(),
+        user_project=[],
+        personas=[],
+        boost=0,
+        aggregated_chunk_boost_factor=1.0,
+        tenant_id="test_tenant",
+    )
+
+
+def _make_indexing_metadata(
+    doc_ids: list[str],
+    old_counts: list[int],
+    new_counts: list[int],
+) -> IndexingMetadata:
+    return IndexingMetadata(
+        doc_id_to_chunk_cnt_diff={
+            doc_id: IndexingMetadata.ChunkCounts(
+                old_chunk_cnt=old,
+                new_chunk_cnt=new,
+            )
+            for doc_id, old, new in zip(doc_ids, old_counts, new_counts)
+        }
+    )
+
+
+def _stub_enrich(
+    doc_id: str,
+    old_chunk_cnt: int,
+) -> EnrichedDocumentIndexingInfo:
+    """Build an EnrichedDocumentIndexingInfo that says 'no chunks to delete'
+    when old_chunk_cnt == 0, or 'has existing chunks' otherwise."""
+    return EnrichedDocumentIndexingInfo(
+        doc_id=doc_id,
+        chunk_start_index=0,
+        old_version=False,
+        chunk_end_index=old_chunk_cnt,
+    )
+
+
+@patch("onyx.document_index.vespa.vespa_document_index.batch_index_vespa_chunks")
+@patch("onyx.document_index.vespa.vespa_document_index.delete_vespa_chunks")
+@patch(
+    "onyx.document_index.vespa.vespa_document_index.get_document_chunk_ids",
+    return_value=[],
+)
+@patch("onyx.document_index.vespa.vespa_document_index._enrich_basic_chunk_info")
+@patch(
+    "onyx.document_index.vespa.vespa_document_index.BATCH_SIZE",
+    3,
+)
+def test_index_respects_batch_size(
+    mock_enrich: MagicMock,
+    mock_get_chunk_ids: MagicMock,  # noqa: ARG001
+    mock_delete: MagicMock,  # noqa: ARG001
+    mock_batch_index: MagicMock,
+) -> None:
+    """When chunks exceed BATCH_SIZE, batch_index_vespa_chunks is called
+    multiple times with correctly sized batches."""
+    mock_enrich.return_value = _stub_enrich("doc1", old_chunk_cnt=0)
+
+    index = VespaDocumentIndex(
+        index_name="test_index",
+        tenant_state=TenantState(tenant_id="test_tenant", multitenant=False),
+        large_chunks_enabled=False,
+        httpx_client=MagicMock(),
+    )
+
+    chunks = [_make_chunk("doc1", chunk_id=i) for i in range(7)]
+    metadata = _make_indexing_metadata(["doc1"], old_counts=[0], new_counts=[7])
+
+    results = index.index(chunks=chunks, indexing_metadata=metadata)
+
+    assert len(results) == 1
+
+    # With BATCH_SIZE=3 and 7 chunks: batches of 3, 3, 1
+    assert mock_batch_index.call_count == 3
+    batch_sizes = [len(c.kwargs["chunks"]) for c in mock_batch_index.call_args_list]
+    assert batch_sizes == [3, 3, 1]
+
+    # Verify all chunks are accounted for and in order
+    all_indexed = [
+        chunk for c in mock_batch_index.call_args_list for chunk in c.kwargs["chunks"]
+    ]
+    assert len(all_indexed) == 7
+    assert [c.chunk_id for c in all_indexed] == list(range(7))

backend/tests/unit/onyx/indexing/test_embed_chunks_in_batches.py

@@ -0,0 +1,391 @@
+"""Unit tests for _embed_chunks_to_store.
+
+Tests cover:
+  - Single batch, no failures
+  - Multiple batches, no failures
+  - Failure in a single batch
+  - Cross-batch document failure scrubbing
+  - Later batches skip already-failed docs
+  - Empty input
+  - All chunks fail
+"""
+
+from collections.abc import Callable
+from unittest.mock import MagicMock
+from unittest.mock import patch
+
+from onyx.connectors.models import ConnectorFailure
+from onyx.connectors.models import Document
+from onyx.connectors.models import DocumentFailure
+from onyx.connectors.models import DocumentSource
+from onyx.connectors.models import TextSection
+from onyx.indexing.chunk_batch_store import ChunkBatchStore
+from onyx.indexing.indexing_pipeline import _embed_chunks_to_store
+from onyx.indexing.models import ChunkEmbedding
+from onyx.indexing.models import DocAwareChunk
+from onyx.indexing.models import IndexChunk
+
+
+def _make_doc(doc_id: str) -> Document:
+    return Document(
+        id=doc_id,
+        semantic_identifier="test",
+        source=DocumentSource.FILE,
+        sections=[TextSection(text="test", link=None)],
+        metadata={},
+    )
+
+
+def _make_chunk(doc_id: str, chunk_id: int) -> DocAwareChunk:
+    return DocAwareChunk(
+        chunk_id=chunk_id,
+        blurb="test",
+        content="test content",
+        source_links=None,
+        image_file_id=None,
+        section_continuation=False,
+        source_document=_make_doc(doc_id),
+        title_prefix="",
+        metadata_suffix_semantic="",
+        metadata_suffix_keyword="",
+        mini_chunk_texts=None,
+        large_chunk_id=None,
+        doc_summary="",
+        chunk_context="",
+        contextual_rag_reserved_tokens=0,
+    )
+
+
+def _make_index_chunk(doc_id: str, chunk_id: int) -> IndexChunk:
+    """Create an IndexChunk (a DocAwareChunk with embeddings)."""
+    return IndexChunk(
+        chunk_id=chunk_id,
+        blurb="test",
+        content="test content",
+        source_links=None,
+        image_file_id=None,
+        section_continuation=False,
+        source_document=_make_doc(doc_id),
+        title_prefix="",
+        metadata_suffix_semantic="",
+        metadata_suffix_keyword="",
+        mini_chunk_texts=None,
+        large_chunk_id=None,
+        doc_summary="",
+        chunk_context="",
+        contextual_rag_reserved_tokens=0,
+        embeddings=ChunkEmbedding(
+            full_embedding=[0.1] * 10,
+            mini_chunk_embeddings=[],
+        ),
+        title_embedding=None,
+    )
+
+
+def _make_failure(doc_id: str) -> ConnectorFailure:
+    return ConnectorFailure(
+        failed_document=DocumentFailure(document_id=doc_id, document_link=None),
+        failure_message="embedding failed",
+        exception=RuntimeError("embedding failed"),
+    )
+
+
+def _mock_embed_success(
+    chunks: list[DocAwareChunk], **_kwargs: object
+) -> tuple[list[IndexChunk], list[ConnectorFailure]]:
+    """Simulate successful embedding of all chunks."""
+    return (
+        [_make_index_chunk(c.source_document.id, c.chunk_id) for c in chunks],
+        [],
+    )
+
+
+def _mock_embed_fail_doc(
+    fail_doc_id: str,
+) -> Callable[..., tuple[list[IndexChunk], list[ConnectorFailure]]]:
+    """Return an embed mock that fails all chunks for a specific doc."""
+
+    def _embed(
+        chunks: list[DocAwareChunk], **_kwargs: object
+    ) -> tuple[list[IndexChunk], list[ConnectorFailure]]:
+        successes = [
+            _make_index_chunk(c.source_document.id, c.chunk_id)
+            for c in chunks
+            if c.source_document.id != fail_doc_id
+        ]
+        failures = (
+            [_make_failure(fail_doc_id)]
+            if any(c.source_document.id == fail_doc_id for c in chunks)
+            else []
+        )
+        return successes, failures
+
+    return _embed
+
+
+class TestEmbedChunksInBatches:
+    @patch(
+        "onyx.indexing.indexing_pipeline.embed_chunks_with_failure_handling",
+    )
+    @patch("onyx.indexing.indexing_pipeline.MAX_CHUNKS_PER_DOC_BATCH", 100)
+    def test_single_batch_no_failures(self, mock_embed: MagicMock) -> None:
+        """All chunks fit in one batch and embed successfully."""
+        mock_embed.side_effect = _mock_embed_success
+
+        with ChunkBatchStore() as store:
+            chunks = [_make_chunk("doc1", i) for i in range(3)]
+            result = _embed_chunks_to_store(
+                chunks=chunks,
+                embedder=MagicMock(),
+                tenant_id="test",
+                request_id=None,
+                store=store,
+            )
+
+            assert len(result.successful_chunk_ids) == 3
+            assert len(result.connector_failures) == 0
+
+            # Verify stored contents
+            assert len(store._batch_files()) == 1
+            stored = list(store.stream())
+            assert len(stored) == 3
+
+    @patch(
+        "onyx.indexing.indexing_pipeline.embed_chunks_with_failure_handling",
+    )
+    @patch("onyx.indexing.indexing_pipeline.MAX_CHUNKS_PER_DOC_BATCH", 3)
+    def test_multiple_batches_no_failures(self, mock_embed: MagicMock) -> None:
+        """Chunks are split across multiple batches, all succeed."""
+        mock_embed.side_effect = _mock_embed_success
+
+        with ChunkBatchStore() as store:
+            chunks = [_make_chunk("doc1", i) for i in range(7)]
+            result = _embed_chunks_to_store(
+                chunks=chunks,
+                embedder=MagicMock(),
+                tenant_id="test",
+                request_id=None,
+                store=store,
+            )
+
+            assert len(result.successful_chunk_ids) == 7
+            assert len(result.connector_failures) == 0
+            assert len(store._batch_files()) == 3  # 3 + 3 + 1
+
+    @patch(
+        "onyx.indexing.indexing_pipeline.embed_chunks_with_failure_handling",
+    )
+    @patch("onyx.indexing.indexing_pipeline.MAX_CHUNKS_PER_DOC_BATCH", 100)
+    def test_single_batch_with_failure(self, mock_embed: MagicMock) -> None:
+        """One doc fails embedding, its chunks are excluded from results."""
+        mock_embed.side_effect = _mock_embed_fail_doc("doc2")
+
+        with ChunkBatchStore() as store:
+            chunks = [
+                _make_chunk("doc1", 0),
+                _make_chunk("doc2", 1),
+                _make_chunk("doc1", 2),
+            ]
+            result = _embed_chunks_to_store(
+                chunks=chunks,
+                embedder=MagicMock(),
+                tenant_id="test",
+                request_id=None,
+                store=store,
+            )
+
+            assert len(result.connector_failures) == 1
+            successful_doc_ids = {doc_id for _, doc_id in result.successful_chunk_ids}
+            assert "doc2" not in successful_doc_ids
+            assert "doc1" in successful_doc_ids
+
+    @patch(
+        "onyx.indexing.indexing_pipeline.embed_chunks_with_failure_handling",
+    )
+    @patch("onyx.indexing.indexing_pipeline.MAX_CHUNKS_PER_DOC_BATCH", 3)
+    def test_cross_batch_failure_scrubs_earlier_batch(
+        self, mock_embed: MagicMock
+    ) -> None:
+        """Doc A spans batches 0 and 1.  It succeeds in batch 0 but fails in
+        batch 1.  Its chunks should be scrubbed from batch 0's batch file."""
+        call_count = 0
+
+        def _embed(
+            chunks: list[DocAwareChunk], **_kwargs: object
+        ) -> tuple[list[IndexChunk], list[ConnectorFailure]]:
+            nonlocal call_count
+            call_count += 1
+            if call_count == 1:
+                return _mock_embed_success(chunks)
+            else:
+                return _mock_embed_fail_doc("docA")(chunks)
+
+        mock_embed.side_effect = _embed
+
+        with ChunkBatchStore() as store:
+            chunks = [
+                _make_chunk("docA", 0),
+                _make_chunk("docA", 1),
+                _make_chunk("docA", 2),
+                _make_chunk("docA", 3),
+                _make_chunk("docB", 0),
+                _make_chunk("docB", 1),
+            ]
+            result = _embed_chunks_to_store(
+                chunks=chunks,
+                embedder=MagicMock(),
+                tenant_id="test",
+                request_id=None,
+                store=store,
+            )
+
+            # docA should be fully excluded from results
+            successful_doc_ids = {doc_id for _, doc_id in result.successful_chunk_ids}
+            assert "docA" not in successful_doc_ids
+            assert "docB" in successful_doc_ids
+            assert len(result.connector_failures) == 1
+
+            # Verify batch 0 was scrubbed of docA chunks
+            all_stored = list(store.stream())
+            stored_doc_ids = {c.source_document.id for c in all_stored}
+            assert "docA" not in stored_doc_ids
+            assert "docB" in stored_doc_ids
+
+    @patch(
+        "onyx.indexing.indexing_pipeline.embed_chunks_with_failure_handling",
+    )
+    @patch("onyx.indexing.indexing_pipeline.MAX_CHUNKS_PER_DOC_BATCH", 3)
+    def test_later_batch_skips_already_failed_doc(self, mock_embed: MagicMock) -> None:
+        """If docA fails in batch 0, its chunks in batch 1 are skipped
+        entirely (never sent to the embedder)."""
+        embedded_doc_ids: list[str] = []
+
+        def _embed(
+            chunks: list[DocAwareChunk], **_kwargs: object
+        ) -> tuple[list[IndexChunk], list[ConnectorFailure]]:
+            for c in chunks:
+                embedded_doc_ids.append(c.source_document.id)
+            return _mock_embed_fail_doc("docA")(chunks)
+
+        mock_embed.side_effect = _embed
+
+        with ChunkBatchStore() as store:
+            chunks = [
+                _make_chunk("docA", 0),
+                _make_chunk("docA", 1),
+                _make_chunk("docA", 2),
+                _make_chunk("docA", 3),
+                _make_chunk("docB", 0),
+                _make_chunk("docB", 1),
+            ]
+            _embed_chunks_to_store(
+                chunks=chunks,
+                embedder=MagicMock(),
+                tenant_id="test",
+                request_id=None,
+                store=store,
+            )
+
+        # docA should only appear in batch 0, not batch 1
+        batch_1_doc_ids = embedded_doc_ids[3:]
+        assert "docA" not in batch_1_doc_ids
+
+    @patch(
+        "onyx.indexing.indexing_pipeline.embed_chunks_with_failure_handling",
+    )
+    @patch("onyx.indexing.indexing_pipeline.MAX_CHUNKS_PER_DOC_BATCH", 3)
+    def test_failed_doc_skipped_in_later_batch_while_other_doc_succeeds(
+        self, mock_embed: MagicMock
+    ) -> None:
+        """doc1 spans batches 0 and 1, doc2 only in batch 1.  Batch 0 fails
+        doc1.  In batch 1, doc1 chunks should be skipped but doc2 chunks
+        should still be embedded successfully."""
+        embedded_chunks: list[list[str]] = []
+
+        def _embed(
+            chunks: list[DocAwareChunk], **_kwargs: object
+        ) -> tuple[list[IndexChunk], list[ConnectorFailure]]:
+            embedded_chunks.append([c.source_document.id for c in chunks])
+            return _mock_embed_fail_doc("doc1")(chunks)
+
+        mock_embed.side_effect = _embed
+
+        with ChunkBatchStore() as store:
+            chunks = [
+                _make_chunk("doc1", 0),
+                _make_chunk("doc1", 1),
+                _make_chunk("doc1", 2),
+                _make_chunk("doc1", 3),
+                _make_chunk("doc2", 0),
+                _make_chunk("doc2", 1),
+            ]
+            result = _embed_chunks_to_store(
+                chunks=chunks,
+                embedder=MagicMock(),
+                tenant_id="test",
+                request_id=None,
+                store=store,
+            )
+
+            # doc1 should be fully excluded, doc2 fully included
+            successful_doc_ids = {doc_id for _, doc_id in result.successful_chunk_ids}
+            assert "doc1" not in successful_doc_ids
+            assert "doc2" in successful_doc_ids
+            assert len(result.successful_chunk_ids) == 2  # doc2's 2 chunks
+
+            # Batch 1 should only contain doc2 (doc1 was filtered before embedding)
+            assert len(embedded_chunks) == 2
+            assert "doc1" not in embedded_chunks[1]
+            assert embedded_chunks[1] == ["doc2", "doc2"]
+
+            # Verify on-disk state has no doc1 chunks
+            all_stored = list(store.stream())
+            assert all(c.source_document.id == "doc2" for c in all_stored)
+
+    @patch(
+        "onyx.indexing.indexing_pipeline.embed_chunks_with_failure_handling",
+    )
+    def test_empty_input(self, mock_embed: MagicMock) -> None:
+        """Empty chunk list produces empty results."""
+        mock_embed.side_effect = _mock_embed_success
+
+        with ChunkBatchStore() as store:
+            result = _embed_chunks_to_store(
+                chunks=[],
+                embedder=MagicMock(),
+                tenant_id="test",
+                request_id=None,
+                store=store,
+            )
+
+            assert len(result.successful_chunk_ids) == 0
+            assert len(result.connector_failures) == 0
+            mock_embed.assert_not_called()
+
+    @patch(
+        "onyx.indexing.indexing_pipeline.embed_chunks_with_failure_handling",
+    )
+    @patch("onyx.indexing.indexing_pipeline.MAX_CHUNKS_PER_DOC_BATCH", 100)
+    def test_all_chunks_fail(self, mock_embed: MagicMock) -> None:
+        """When all documents fail, results have no successful chunks."""
+
+        def _fail_all(
+            chunks: list[DocAwareChunk], **_kwargs: object
+        ) -> tuple[list[IndexChunk], list[ConnectorFailure]]:
+            doc_ids = {c.source_document.id for c in chunks}
+            return [], [_make_failure(doc_id) for doc_id in doc_ids]
+
+        mock_embed.side_effect = _fail_all
+
+        with ChunkBatchStore() as store:
+            chunks = [_make_chunk("doc1", 0), _make_chunk("doc2", 1)]
+            result = _embed_chunks_to_store(
+                chunks=chunks,
+                embedder=MagicMock(),
+                tenant_id="test",
+                request_id=None,
+                store=store,
+            )
+
+            assert len(result.successful_chunk_ids) == 0
+            assert len(result.connector_failures) == 2

backend/tests/unit/onyx/indexing/test_personas_in_chunks.py

@@ -116,7 +116,7 @@ def _run_adapter_build(
     project_ids_map: dict[str, list[int]],
     persona_ids_map: dict[str, list[int]],
 ) -> list[DocMetadataAwareIndexChunk]:
-    """Helper that runs UserFileIndexingAdapter.build_metadata_aware_chunks
+    """Helper that runs UserFileIndexingAdapter.prepare_enrichment + enrich_chunk
     with all external dependencies mocked."""
     from onyx.indexing.adapters.user_file_indexing_adapter import (
         UserFileIndexingAdapter,
@@ -155,18 +155,16 @@ def _run_adapter_build(
             side_effect=Exception("no LLM in tests"),
         ),
     ):
-        result = adapter.build_metadata_aware_chunks(
-            chunks_with_embeddings=[chunk],
-            chunk_content_scores=[1.0],
-            tenant_id="test_tenant",
+        enricher = adapter.prepare_enrichment(
             context=context,
+            tenant_id="test_tenant",
+            chunks=[chunk],
         )
-
-    return result.chunks
+        return [enricher.enrich_chunk(chunk, 1.0)]
 
 
-def test_build_metadata_aware_chunks_includes_persona_ids() -> None:
-    """UserFileIndexingAdapter.build_metadata_aware_chunks writes persona IDs
+def test_prepare_enrichment_includes_persona_ids() -> None:
+    """UserFileIndexingAdapter.prepare_enrichment writes persona IDs
     fetched from the DB into each chunk's metadata."""
     file_id = str(uuid4())
     persona_ids = [5, 12]
@@ -183,7 +181,7 @@ def test_build_metadata_aware_chunks_includes_persona_ids() -> None:
     assert chunks[0].user_project == project_ids
 
 
-def test_build_metadata_aware_chunks_missing_file_defaults_to_empty() -> None:
+def test_prepare_enrichment_missing_file_defaults_to_empty() -> None:
     """When a file has no persona or project associations in the DB, the
     adapter should default to empty lists (not KeyError or None)."""
     file_id = str(uuid4())

backend/tests/unit/tools/test_memory_tool_packets.py

@@ -1,6 +1,6 @@
 """Tests for memory tool streaming packet emissions."""
 
-from queue import Queue
+import queue
 from unittest.mock import MagicMock
 from unittest.mock import patch
 
@@ -18,9 +18,13 @@ from onyx.tools.tool_implementations.memory.models import MemoryToolResponse
 
 
 @pytest.fixture
-def emitter() -> Emitter:
-    bus: Queue = Queue()
-    return Emitter(bus)
+def emitter_queue() -> queue.Queue:
+    return queue.Queue()
+
+
+@pytest.fixture
+def emitter(emitter_queue: queue.Queue) -> Emitter:
+    return Emitter(merged_queue=emitter_queue)
 
 
 @pytest.fixture
@@ -53,24 +57,27 @@ class TestMemoryToolEmitStart:
     def test_emit_start_emits_memory_tool_start_packet(
         self,
         memory_tool: MemoryTool,
-        emitter: Emitter,
+        emitter_queue: queue.Queue,
         placement: Placement,
     ) -> None:
         memory_tool.emit_start(placement)
 
-        packet = emitter.bus.get_nowait()
+        _key, packet = emitter_queue.get_nowait()
         assert isinstance(packet.obj, MemoryToolStart)
-        assert packet.placement == placement
+        assert packet.placement is not None
+        assert packet.placement.turn_index == placement.turn_index
+        assert packet.placement.tab_index == placement.tab_index
+        assert packet.placement.model_index == 0  # emitter stamps model_index=0
 
     def test_emit_start_with_different_placement(
         self,
         memory_tool: MemoryTool,
-        emitter: Emitter,
+        emitter_queue: queue.Queue,
     ) -> None:
         placement = Placement(turn_index=2, tab_index=1)
         memory_tool.emit_start(placement)
 
-        packet = emitter.bus.get_nowait()
+        _key, packet = emitter_queue.get_nowait()
         assert packet.placement.turn_index == 2
         assert packet.placement.tab_index == 1
 
@@ -81,7 +88,7 @@ class TestMemoryToolRun:
         self,
         mock_process: MagicMock,
         memory_tool: MemoryTool,
-        emitter: Emitter,
+        emitter_queue: queue.Queue,
         placement: Placement,
         override_kwargs: MemoryToolOverrideKwargs,
     ) -> None:
@@ -93,21 +100,19 @@ class TestMemoryToolRun:
             memory="User prefers Python",
         )
 
-        # The delta packet should be in the queue
-        packet = emitter.bus.get_nowait()
+        _key, packet = emitter_queue.get_nowait()
         assert isinstance(packet.obj, MemoryToolDelta)
         assert packet.obj.memory_text == "User prefers Python"
         assert packet.obj.operation == "add"
         assert packet.obj.memory_id is None
         assert packet.obj.index is None
-        assert packet.placement == placement
 
     @patch("onyx.tools.tool_implementations.memory.memory_tool.process_memory_update")
     def test_run_emits_delta_for_update_operation(
         self,
         mock_process: MagicMock,
         memory_tool: MemoryTool,
-        emitter: Emitter,
+        emitter_queue: queue.Queue,
         placement: Placement,
         override_kwargs: MemoryToolOverrideKwargs,
     ) -> None:
@@ -119,7 +124,7 @@ class TestMemoryToolRun:
             memory="User prefers light mode",
         )
 
-        packet = emitter.bus.get_nowait()
+        _key, packet = emitter_queue.get_nowait()
         assert isinstance(packet.obj, MemoryToolDelta)
         assert packet.obj.memory_text == "User prefers light mode"
         assert packet.obj.operation == "update"

uv.lock

@@ -5634,11 +5634,11 @@ wheels = [
 
 [[package]]
 name = "pygments"
-version = "2.19.2"
+version = "2.20.0"
 source = { registry = "https://pypi.org/simple" }
-sdist = { url = "https://files.pythonhosted.org/packages/b0/77/a5b8c569bf593b0140bde72ea885a803b82086995367bf2037de0159d924/pygments-2.19.2.tar.gz", hash = "sha256:636cb2477cec7f8952536970bc533bc43743542f70392ae026374600add5b887", size = 4968631, upload-time = "2025-06-21T13:39:12.283Z" }
+sdist = { url = "https://files.pythonhosted.org/packages/c3/b2/bc9c9196916376152d655522fdcebac55e66de6603a76a02bca1b6414f6c/pygments-2.20.0.tar.gz", hash = "sha256:6757cd03768053ff99f3039c1a36d6c0aa0b263438fcab17520b30a303a82b5f", size = 4955991, upload-time = "2026-03-29T13:29:33.898Z" }
 wheels = [
-    { url = "https://files.pythonhosted.org/packages/c7/21/705964c7812476f378728bdf590ca4b771ec72385c533964653c68e86bdc/pygments-2.19.2-py3-none-any.whl", hash = "sha256:86540386c03d588bb81d44bc3928634ff26449851e99741617ecb9037ee5ec0b", size = 1225217, upload-time = "2025-06-21T13:39:07.939Z" },
+    { url = "https://files.pythonhosted.org/packages/f4/7e/a72dd26f3b0f4f2bf1dd8923c85f7ceb43172af56d63c7383eb62b332364/pygments-2.20.0-py3-none-any.whl", hash = "sha256:81a9e26dd42fd28a23a2d169d86d7ac03b46e2f8b59ed4698fb4785f946d0176", size = 1231151, upload-time = "2026-03-29T13:29:30.038Z" },
 ]
 
 [[package]]

web/lib/opal/src/components/buttons/button/components.tsx

@@ -104,7 +104,7 @@ function Button({
           isLarge ? "default" : size === "2xs" ? "mini" : "compact"
         }
       >
-        <div className="flex flex-row items-center gap-1 interactive-foreground">
+        <div className="flex flex-row items-center gap-1">
           {iconWrapper(Icon, size, !!children)}
 
           {labelEl}

web/lib/opal/src/components/buttons/filter-button/components.tsx

@@ -67,7 +67,7 @@ function FilterButton({
         state={active ? "selected" : "empty"}
       >
         <Interactive.Container type="button">
-          <div className="interactive-foreground flex flex-row items-center gap-1">
+          <div className="flex flex-row items-center gap-1">
             {iconWrapper(Icon, "lg", true)}
             <Text font="main-ui-action" color="inherit" nowrap>
               {children}

web/lib/opal/src/components/buttons/line-item-button/components.tsx

@@ -16,7 +16,7 @@ import * as TooltipPrimitive from "@radix-ui/react-tooltip";
 
 type ContentPassthroughProps = DistributiveOmit<
   ContentActionProps,
-  "paddingVariant" | "widthVariant" | "ref" | "withInteractive"
+  "paddingVariant" | "widthVariant" | "ref"
 >;
 
 type LineItemButtonOwnProps = Pick<
@@ -92,7 +92,6 @@ function LineItemButton({
       >
         <ContentAction
           {...(contentActionProps as ContentActionProps)}
-          withInteractive
           paddingVariant="fit"
         />
       </Interactive.Container>

web/lib/opal/src/components/buttons/open-button/components.tsx

@@ -132,7 +132,7 @@ function OpenButton({
       >
         <div
           className={cn(
-            "interactive-foreground flex flex-row items-center",
+            "flex flex-row items-center",
             justifyContent === "between" ? "w-full justify-between" : "gap-1",
             foldable &&
               justifyContent !== "between" &&

web/lib/opal/src/components/buttons/select-button/components.tsx

@@ -1,3 +1,5 @@
+"use client";
+
 import "@opal/components/buttons/select-button/styles.css";
 import {
   Interactive,
@@ -84,11 +86,13 @@ function SelectButton({
   const isLarge = size === "lg";
 
   const labelEl = children ? (
-    <span className="opal-select-button-label">
-      <Text font={isLarge ? "main-ui-body" : "secondary-body"} color="inherit">
-        {children}
-      </Text>
-    </span>
+    <Text
+      font={isLarge ? "main-ui-body" : "secondary-body"}
+      color="inherit"
+      nowrap
+    >
+      {children}
+    </Text>
   ) : null;
 
   const button = (
@@ -103,7 +107,7 @@ function SelectButton({
       >
         <div
           className={cn(
-            "opal-select-button interactive-foreground",
+            "opal-select-button",
             foldable && "interactive-foldable-host"
           )}
         >

web/lib/opal/src/components/buttons/select-button/styles.css

@@ -3,7 +3,3 @@
 .opal-select-button {
   @apply flex flex-row items-center gap-1;
 }
-
-.opal-select-button-label {
-  @apply whitespace-nowrap;
-}

web/lib/opal/src/components/cards/select-card/README.md

@@ -0,0 +1,136 @@
+# SelectCard
+
+**Import:** `import { SelectCard, type SelectCardProps } from "@opal/components";`
+
+A stateful interactive card — the card counterpart to [`SelectButton`](../../buttons/select-button/README.md). Built on `Interactive.Stateful` (Slot) with a structural `<div>` that owns padding, rounding, border, and overflow.
+
+## Relationship to Card
+
+`Card` is a plain, non-interactive container. `SelectCard` adds stateful interactivity (hover, active, disabled, state-driven colors) by wrapping its root div with `Interactive.Stateful`. The relationship mirrors `Button` (stateless) vs `SelectButton` (stateful).
+
+## Relationship to SelectButton
+
+SelectCard and SelectButton share the same call stack:
+
+```
+Interactive.Stateful → structural element → content
+```
+
+The key differences:
+
+- SelectCard renders a `<div>` (not `Interactive.Container`) — cards have their own rounding scale (one notch larger than buttons) and don't need Container's height/min-width.
+- SelectCard has no `foldable` prop — use `Interactive.Foldable` directly inside children.
+- SelectCard's children are fully composable — use `CardHeaderLayout`, `ContentAction`, `Content`, buttons, etc. inside.
+
+## Architecture
+
+```
+Interactive.Stateful              <- variant, state, interaction, disabled, onClick
+  └─ div.opal-select-card        <- padding, rounding, border, overflow
+       └─ children (composable)
+```
+
+The `Interactive.Stateful` Slot merges onto the div, producing a single DOM element with both `.opal-select-card` and `.interactive` classes plus `data-interactive-*` attributes. This activates the Stateful color matrix for backgrounds and `--interactive-foreground` / `--interactive-foreground-icon` CSS properties for descendants.
+
+## Props
+
+Inherits **all** props from `InteractiveStatefulProps` (variant, state, interaction, onClick, href, etc.) plus:
+
+| Prop | Type | Default | Description |
+|---|---|---|---|
+| `sizeVariant` | `ContainerSizeVariants` | `"lg"` | Controls padding and border-radius |
+| `ref` | `React.Ref<HTMLDivElement>` | — | Ref forwarded to the root div |
+| `children` | `React.ReactNode` | — | Card content |
+
+### Rounding scale
+
+Cards use a bumped-up rounding scale compared to buttons:
+
+| Size | Rounding | Effective radius |
+|---|---|---|
+| `lg` | `rounded-16` | 1rem (16px) |
+| `md`–`sm` | `rounded-12` | 0.75rem (12px) |
+| `xs`–`2xs` | `rounded-08` | 0.5rem (8px) |
+| `fit` | `rounded-16` | 1rem (16px) |
+
+### Recommended variant: `select-card`
+
+The `select-card` Interactive.Stateful variant is specifically designed for cards. Unlike `select-heavy` (which only changes foreground color between empty and filled), `select-card` gives the filled state a visible background — important on larger surfaces where background carries more of the visual distinction.
+
+| State | Rest background | Rest foreground |
+|---|---|---|
+| `empty` | transparent | `text-04` / icon `text-03` |
+| `filled` | `background-tint-00` | `text-04` / icon `text-03` |
+| `selected` | `action-link-01` | `action-link-05` |
+
+The selected state also gets a `border-action-link-05` via SelectCard's CSS.
+
+## CSS
+
+SelectCard's stylesheet (`styles.css`) provides:
+
+- `w-full overflow-clip border` on all states
+- `border-action-link-05` when `data-interactive-state="selected"`
+
+All background and foreground colors come from the Interactive.Stateful CSS, not from SelectCard.
+
+## Usage
+
+### Provider selection card
+
+```tsx
+import { SelectCard } from "@opal/components";
+import { CardHeaderLayout } from "@opal/layouts";
+
+<SelectCard variant="select-card" state="selected" onClick={handleClick}>
+  <CardHeaderLayout
+    icon={SvgGlobe}
+    title="Google"
+    description="Search engine"
+    sizePreset="main-ui"
+    variant="section"
+    rightChildren={<Button icon={SvgCheckSquare} variant="action" prominence="tertiary">Current Default</Button>}
+    bottomRightChildren={
+      <Button icon={SvgSettings} size="sm" prominence="tertiary" />
+    }
+  />
+</SelectCard>
+```
+
+### Disconnected state (clickable)
+
+```tsx
+<SelectCard variant="select-card" state="empty" onClick={handleConnect}>
+  <CardHeaderLayout
+    icon={SvgCloud}
+    title="OpenAI"
+    description="Not configured"
+    sizePreset="main-ui"
+    variant="section"
+    rightChildren={<Button rightIcon={SvgArrowExchange} prominence="tertiary">Connect</Button>}
+  />
+</SelectCard>
+```
+
+### With foldable hover-reveal
+
+```tsx
+<SelectCard variant="select-card" state="filled">
+  <CardHeaderLayout
+    icon={SvgCloud}
+    title="OpenAI"
+    description="Connected"
+    sizePreset="main-ui"
+    variant="section"
+    rightChildren={
+      <div className="interactive-foldable-host flex items-center">
+        <Interactive.Foldable>
+          <Button rightIcon={SvgArrowRightCircle} prominence="tertiary">
+            Set as Default
+          </Button>
+        </Interactive.Foldable>
+      </div>
+    }
+  />
+</SelectCard>
+```

web/lib/opal/src/components/cards/select-card/SelectCard.stories.tsx

@@ -0,0 +1,247 @@
+import type { Meta, StoryObj } from "@storybook/react";
+import { SelectCard } from "@opal/components";
+import { Button } from "@opal/components";
+import { Content } from "@opal/layouts";
+import {
+  SvgArrowExchange,
+  SvgArrowRightCircle,
+  SvgCheckSquare,
+  SvgGlobe,
+  SvgSettings,
+  SvgUnplug,
+} from "@opal/icons";
+import { Interactive } from "@opal/core";
+import * as TooltipPrimitive from "@radix-ui/react-tooltip";
+import type { Decorator } from "@storybook/react";
+
+const withTooltipProvider: Decorator = (Story) => (
+  <TooltipPrimitive.Provider>
+    <Story />
+  </TooltipPrimitive.Provider>
+);
+
+const STATES = ["empty", "filled", "selected"] as const;
+const SIZE_VARIANTS = ["lg", "md", "sm", "xs", "2xs", "fit"] as const;
+
+const meta = {
+  title: "opal/components/SelectCard",
+  component: SelectCard,
+  tags: ["autodocs"],
+  decorators: [withTooltipProvider],
+  parameters: {
+    layout: "centered",
+  },
+} satisfies Meta<typeof SelectCard>;
+
+export default meta;
+
+type Story = StoryObj<typeof meta>;
+
+// ---------------------------------------------------------------------------
+// Stories
+// ---------------------------------------------------------------------------
+
+export const Default: Story = {
+  render: () => (
+    <div className="w-96">
+      <SelectCard variant="select-card" state="empty">
+        <div className="p-2">
+          <Content
+            sizePreset="main-ui"
+            variant="section"
+            icon={SvgGlobe}
+            title="Google Search"
+            description="Web search provider"
+          />
+        </div>
+      </SelectCard>
+    </div>
+  ),
+};
+
+export const AllStates: Story = {
+  render: () => (
+    <div className="flex flex-col gap-4 w-96">
+      {STATES.map((state) => (
+        <SelectCard key={state} variant="select-card" state={state}>
+          <div className="p-2">
+            <Content
+              sizePreset="main-ui"
+              variant="section"
+              icon={SvgGlobe}
+              title={`State: ${state}`}
+              description="Hover to see interaction states."
+            />
+          </div>
+        </SelectCard>
+      ))}
+    </div>
+  ),
+};
+
+export const Clickable: Story = {
+  render: () => (
+    <div className="w-96">
+      <SelectCard
+        variant="select-card"
+        state="empty"
+        onClick={() => alert("Card clicked")}
+      >
+        <div className="p-2">
+          <Content
+            sizePreset="main-ui"
+            variant="section"
+            icon={SvgGlobe}
+            title="Clickable Card"
+            description="Click anywhere on this card."
+          />
+        </div>
+      </SelectCard>
+    </div>
+  ),
+};
+
+export const WithActions: Story = {
+  render: () => (
+    <div className="flex flex-col gap-4 w-[28rem]">
+      {/* Disconnected */}
+      <SelectCard variant="select-card" state="empty" onClick={() => {}}>
+        <div className="flex flex-row items-stretch w-full">
+          <div className="flex-1 p-2">
+            <Content
+              sizePreset="main-ui"
+              variant="section"
+              icon={SvgGlobe}
+              title="Disconnected"
+              description="Click to connect."
+            />
+          </div>
+          <div className="flex items-center">
+            <Button prominence="tertiary" rightIcon={SvgArrowExchange}>
+              Connect
+            </Button>
+          </div>
+        </div>
+      </SelectCard>
+
+      {/* Connected with foldable */}
+      <SelectCard variant="select-card" state="filled">
+        <div className="flex flex-row items-stretch w-full">
+          <div className="flex-1 p-2">
+            <Content
+              sizePreset="main-ui"
+              variant="section"
+              icon={SvgGlobe}
+              title="Connected"
+              description="Hover to reveal Set as Default."
+            />
+          </div>
+          <div className="flex flex-col items-end justify-between">
+            <div className="interactive-foldable-host flex items-center">
+              <Interactive.Foldable>
+                <Button prominence="tertiary" rightIcon={SvgArrowRightCircle}>
+                  Set as Default
+                </Button>
+              </Interactive.Foldable>
+            </div>
+            <div className="flex flex-row px-1 pb-1">
+              <Button
+                icon={SvgUnplug}
+                tooltip="Disconnect"
+                prominence="tertiary"
+                size="sm"
+              />
+              <Button
+                icon={SvgSettings}
+                tooltip="Edit"
+                prominence="tertiary"
+                size="sm"
+              />
+            </div>
+          </div>
+        </div>
+      </SelectCard>
+
+      {/* Selected */}
+      <SelectCard variant="select-card" state="selected">
+        <div className="flex flex-row items-stretch w-full">
+          <div className="flex-1 p-2">
+            <Content
+              sizePreset="main-ui"
+              variant="section"
+              icon={SvgGlobe}
+              title="Selected"
+              description="Currently the default provider."
+            />
+          </div>
+          <div className="flex flex-col items-end justify-between">
+            <Button
+              variant="action"
+              prominence="tertiary"
+              icon={SvgCheckSquare}
+            >
+              Current Default
+            </Button>
+            <div className="flex flex-row px-1 pb-1">
+              <Button
+                icon={SvgUnplug}
+                tooltip="Disconnect"
+                prominence="tertiary"
+                size="sm"
+              />
+              <Button
+                icon={SvgSettings}
+                tooltip="Edit"
+                prominence="tertiary"
+                size="sm"
+              />
+            </div>
+          </div>
+        </div>
+      </SelectCard>
+    </div>
+  ),
+};
+
+export const SizeVariants: Story = {
+  render: () => (
+    <div className="flex flex-col gap-4 w-96">
+      {SIZE_VARIANTS.map((size) => (
+        <SelectCard
+          key={size}
+          variant="select-card"
+          state="filled"
+          sizeVariant={size}
+        >
+          <Content
+            sizePreset="main-ui"
+            variant="section"
+            icon={SvgGlobe}
+            title={`sizeVariant: ${size}`}
+            description="Shows padding and rounding differences."
+          />
+        </SelectCard>
+      ))}
+    </div>
+  ),
+};
+
+export const SelectHeavyVariant: Story = {
+  render: () => (
+    <div className="flex flex-col gap-4 w-96">
+      {STATES.map((state) => (
+        <SelectCard key={state} variant="select-heavy" state={state}>
+          <div className="p-2">
+            <Content
+              sizePreset="main-ui"
+              variant="section"
+              icon={SvgGlobe}
+              title={`select-heavy / ${state}`}
+              description="For comparison with select-card variant."
+            />
+          </div>
+        </SelectCard>
+      ))}
+    </div>
+  ),
+};

web/lib/opal/src/components/cards/select-card/components.tsx

@@ -0,0 +1,96 @@
+import "@opal/components/cards/select-card/styles.css";
+import type { ContainerSizeVariants } from "@opal/types";
+import { containerSizeVariants } from "@opal/shared";
+import { cn } from "@opal/utils";
+import { Interactive, type InteractiveStatefulProps } from "@opal/core";
+
+// ---------------------------------------------------------------------------
+// Types
+// ---------------------------------------------------------------------------
+
+type SelectCardProps = InteractiveStatefulProps & {
+  /**
+   * Size preset — controls padding and border-radius.
+   *
+   * Padding comes from the shared size scale. Rounding follows the same
+   * mapping as `Card` / `Button` / `Interactive.Container`:
+   *
+   * | Size       | Rounding     |
+   * |------------|--------------|
+   * | `lg`       | `rounded-16` |
+   * | `md`–`sm`  | `rounded-12` |
+   * | `xs`–`2xs` | `rounded-08` |
+   * | `fit`      | `rounded-16` |
+   *
+   * @default "lg"
+   */
+  sizeVariant?: ContainerSizeVariants;
+
+  /** Ref forwarded to the root `<div>`. */
+  ref?: React.Ref<HTMLDivElement>;
+
+  children?: React.ReactNode;
+};
+
+// ---------------------------------------------------------------------------
+// Rounding
+// ---------------------------------------------------------------------------
+
+const roundingForSize: Record<ContainerSizeVariants, string> = {
+  lg: "rounded-16",
+  md: "rounded-12",
+  sm: "rounded-12",
+  xs: "rounded-08",
+  "2xs": "rounded-08",
+  fit: "rounded-16",
+};
+
+// ---------------------------------------------------------------------------
+// SelectCard
+// ---------------------------------------------------------------------------
+
+/**
+ * A stateful interactive card — the card counterpart to `SelectButton`.
+ *
+ * Built on `Interactive.Stateful` (Slot) → a structural `<div>`. The
+ * Stateful system owns background and foreground colors; the card owns
+ * padding, rounding, border, and overflow.
+ *
+ * Children are fully composable — use `ContentAction`, `Content`, buttons,
+ * `Interactive.Foldable`, etc. inside.
+ *
+ * @example
+ * ```tsx
+ * <SelectCard variant="select-card" state="selected" onClick={handleClick}>
+ *   <ContentAction
+ *     icon={SvgGlobe}
+ *     title="Google"
+ *     description="Search engine"
+ *     rightChildren={<Button>Set as Default</Button>}
+ *   />
+ * </SelectCard>
+ * ```
+ */
+function SelectCard({
+  sizeVariant = "lg",
+  ref,
+  children,
+  ...statefulProps
+}: SelectCardProps) {
+  const { padding } = containerSizeVariants[sizeVariant];
+  const rounding = roundingForSize[sizeVariant];
+
+  return (
+    <Interactive.Stateful {...statefulProps}>
+      <div ref={ref} className={cn("opal-select-card", padding, rounding)}>
+        {children}
+      </div>
+    </Interactive.Stateful>
+  );
+}
+
+// ---------------------------------------------------------------------------
+// Exports
+// ---------------------------------------------------------------------------
+
+export { SelectCard, type SelectCardProps };

web/lib/opal/src/components/cards/select-card/styles.css

@@ -0,0 +1,9 @@
+/* SelectCard — structural styles; colors handled by Interactive.Stateful */
+
+.opal-select-card {
+  @apply w-full overflow-clip border;
+}
+
+.opal-select-card[data-interactive-state="selected"] {
+  @apply border-action-link-05;
+}

web/lib/opal/src/components/index.ts

@@ -56,6 +56,12 @@ export {
   type BorderVariant,
 } from "@opal/components/cards/card/components";
 
+/* SelectCard */
+export {
+  SelectCard,
+  type SelectCardProps,
+} from "@opal/components/cards/select-card/components";
+
 /* EmptyMessageCard */
 export {
   EmptyMessageCard,

web/lib/opal/src/components/pagination/components.tsx

@@ -390,14 +390,12 @@ function PaginationCount({
         <span className={textClasses(size, "muted")}>of</span>
         {totalItems}
         {units && (
-          <span className="ml-1">
-            <Text
-              color="inherit"
-              font={size === "sm" ? "secondary-body" : "main-ui-muted"}
-            >
-              {units}
-            </Text>
-          </span>
+          <Text
+            color="inherit"
+            font={size === "sm" ? "secondary-body" : "main-ui-muted"}
+          >
+            {units}
+          </Text>
         )}
       </span>
 

web/lib/opal/src/components/tag/components.tsx

@@ -1,5 +1,4 @@
 import "@opal/components/tag/styles.css";
-
 import type { IconFunctionComponent, RichStr } from "@opal/types";
 import { Text } from "@opal/components";
 import { cn } from "@opal/utils";
@@ -46,20 +45,22 @@ function Tag({ icon: Icon, title, color = "gray", size = "sm" }: TagProps) {
   const config = COLOR_CONFIG[color];
 
   return (
-    <div className={cn("opal-auxiliary-tag", config.bg)} data-size={size}>
+    <div
+      className={cn("opal-auxiliary-tag", config.bg, config.text)}
+      data-size={size}
+    >
       {Icon && (
         <div className="opal-auxiliary-tag-icon-container">
           <Icon className={cn("opal-auxiliary-tag-icon", config.text)} />
         </div>
       )}
-      <span className={cn("opal-auxiliary-tag-title px-[2px]", config.text)}>
-        <Text
-          font={size === "md" ? "secondary-body" : "figure-small-value"}
-          color="inherit"
-        >
-          {title}
-        </Text>
-      </span>
+      <Text
+        font={size === "md" ? "secondary-body" : "figure-small-value"}
+        color="inherit"
+        nowrap
+      >
+        {title}
+      </Text>
     </div>
   );
 }

web/lib/opal/src/components/text/InlineMarkdown.tsx

@@ -13,7 +13,9 @@ const SAFE_PROTOCOL = /^https?:|^mailto:|^tel:/i;
 const ALLOWED_ELEMENTS = ["p", "br", "a", "strong", "em", "code", "del"];
 
 const INLINE_COMPONENTS = {
-  p: ({ children }: { children?: ReactNode }) => <>{children}</>,
+  p: ({ children }: { children?: ReactNode }) => (
+    <span className="block">{children}</span>
+  ),
   a: ({ children, href }: { children?: ReactNode; href?: string }) => {
     if (!href || !SAFE_PROTOCOL.test(href)) {
       return <>{children}</>;

web/lib/opal/src/components/text/components.tsx

@@ -125,6 +125,7 @@ function Text({
   ...rest
 }: TextProps) {
   const resolvedClassName = cn(
+    "px-[2px]",
     FONT_CONFIG[font],
     COLOR_CONFIG[color],
     nowrap && "whitespace-nowrap",

web/lib/opal/src/core/index.ts

@@ -18,9 +18,11 @@ export {
 import { InteractiveStateless } from "@opal/core/interactive/stateless/components";
 import { InteractiveStateful } from "@opal/core/interactive/stateful/components";
 import { InteractiveContainer } from "@opal/core/interactive/container/components";
+import { InteractiveSimple } from "@opal/core/interactive/simple/components";
 import { Foldable } from "@opal/core/interactive/foldable/components";
 
 const Interactive = {
+  Simple: InteractiveSimple,
   Stateless: InteractiveStateless,
   Stateful: InteractiveStateful,
   Container: InteractiveContainer,
@@ -50,3 +52,5 @@ export type {
 } from "@opal/core/interactive/container/components";
 
 export type { FoldableProps } from "@opal/core/interactive/foldable/components";
+
+export type { InteractiveSimpleProps } from "@opal/core/interactive/simple/components";

web/lib/opal/src/core/interactive/Interactive.stories.tsx

@@ -9,7 +9,6 @@ const VARIANT_PROMINENCE_MAP: Record<string, string[]> = {
   default: ["primary", "secondary", "tertiary", "internal"],
   action: ["primary", "secondary", "tertiary", "internal"],
   danger: ["primary", "secondary", "tertiary", "internal"],
-  none: [],
 };
 
 const SIZE_VARIANTS = ["lg", "md", "sm", "xs", "2xs", "fit"] as const;
@@ -43,7 +42,7 @@ export const Default: StoryObj = {
         onClick={() => {}}
       >
         <Interactive.Container border>
-          <span className="interactive-foreground">Secondary</span>
+          <span>Secondary</span>
         </Interactive.Container>
       </Interactive.Stateless>
 
@@ -53,7 +52,7 @@ export const Default: StoryObj = {
         onClick={() => {}}
       >
         <Interactive.Container border>
-          <span className="interactive-foreground">Primary</span>
+          <span>Primary</span>
         </Interactive.Container>
       </Interactive.Stateless>
 
@@ -63,7 +62,7 @@ export const Default: StoryObj = {
         onClick={() => {}}
       >
         <Interactive.Container border>
-          <span className="interactive-foreground">Tertiary</span>
+          <span>Tertiary</span>
         </Interactive.Container>
       </Interactive.Stateless>
     </div>
@@ -115,9 +114,7 @@ export const VariantMatrix: StoryObj = {
                     onClick={() => {}}
                   >
                     <Interactive.Container border>
-                      <span className="interactive-foreground">
-                        {prominence}
-                      </span>
+                      <span>{prominence}</span>
                     </Interactive.Container>
                   </Interactive.Stateless>
                   <span
@@ -150,7 +147,7 @@ export const Sizes: StoryObj = {
           onClick={() => {}}
         >
           <Interactive.Container border heightVariant={size}>
-            <span className="interactive-foreground">{size}</span>
+            <span>{size}</span>
           </Interactive.Container>
         </Interactive.Stateless>
       ))}
@@ -168,7 +165,7 @@ export const WidthFull: StoryObj = {
         onClick={() => {}}
       >
         <Interactive.Container border widthVariant="full">
-          <span className="interactive-foreground">Full width container</span>
+          <span>Full width container</span>
         </Interactive.Container>
       </Interactive.Stateless>
     </div>
@@ -187,7 +184,7 @@ export const Rounding: StoryObj = {
           onClick={() => {}}
         >
           <Interactive.Container border roundingVariant={rounding}>
-            <span className="interactive-foreground">{rounding}</span>
+            <span>{rounding}</span>
           </Interactive.Container>
         </Interactive.Stateless>
       ))}
@@ -207,7 +204,7 @@ export const DisabledStory: StoryObj = {
           onClick={() => {}}
         >
           <Interactive.Container border>
-            <span className="interactive-foreground">Disabled</span>
+            <span>Disabled</span>
           </Interactive.Container>
         </Interactive.Stateless>
       </Disabled>
@@ -218,7 +215,7 @@ export const DisabledStory: StoryObj = {
         onClick={() => {}}
       >
         <Interactive.Container border>
-          <span className="interactive-foreground">Enabled</span>
+          <span>Enabled</span>
         </Interactive.Container>
       </Interactive.Stateless>
     </div>
@@ -236,7 +233,7 @@ export const Interaction: StoryObj = {
         onClick={() => {}}
       >
         <Interactive.Container border>
-          <span className="interactive-foreground">Forced hover</span>
+          <span>Forced hover</span>
         </Interactive.Container>
       </Interactive.Stateless>
 
@@ -247,7 +244,7 @@ export const Interaction: StoryObj = {
         onClick={() => {}}
       >
         <Interactive.Container border>
-          <span className="interactive-foreground">Forced active</span>
+          <span>Forced active</span>
         </Interactive.Container>
       </Interactive.Stateless>
 
@@ -257,7 +254,7 @@ export const Interaction: StoryObj = {
         onClick={() => {}}
       >
         <Interactive.Container border>
-          <span className="interactive-foreground">Normal (rest)</span>
+          <span>Normal (rest)</span>
         </Interactive.Container>
       </Interactive.Stateless>
     </div>
@@ -274,7 +271,7 @@ export const WithBorder: StoryObj = {
         onClick={() => {}}
       >
         <Interactive.Container border>
-          <span className="interactive-foreground">With border</span>
+          <span>With border</span>
         </Interactive.Container>
       </Interactive.Stateless>
 
@@ -284,7 +281,7 @@ export const WithBorder: StoryObj = {
         onClick={() => {}}
       >
         <Interactive.Container>
-          <span className="interactive-foreground">Without border</span>
+          <span>Without border</span>
         </Interactive.Container>
       </Interactive.Stateless>
     </div>
@@ -296,7 +293,7 @@ export const AsLink: StoryObj = {
   render: () => (
     <Interactive.Stateless variant="action" href="/settings">
       <Interactive.Container border>
-        <span className="interactive-foreground">Go to Settings</span>
+        <span>Go to Settings</span>
       </Interactive.Container>
     </Interactive.Stateless>
   ),
@@ -312,7 +309,7 @@ export const SelectVariant: StoryObj = {
         onClick={() => {}}
       >
         <Interactive.Container border>
-          <span className="interactive-foreground">Selected (light)</span>
+          <span>Selected (light)</span>
         </Interactive.Container>
       </Interactive.Stateful>
 
@@ -322,7 +319,7 @@ export const SelectVariant: StoryObj = {
         onClick={() => {}}
       >
         <Interactive.Container border>
-          <span className="interactive-foreground">Unselected (light)</span>
+          <span>Unselected (light)</span>
         </Interactive.Container>
       </Interactive.Stateful>
 
@@ -332,7 +329,7 @@ export const SelectVariant: StoryObj = {
         onClick={() => {}}
       >
         <Interactive.Container border>
-          <span className="interactive-foreground">Selected (heavy)</span>
+          <span>Selected (heavy)</span>
         </Interactive.Container>
       </Interactive.Stateful>
 
@@ -342,7 +339,7 @@ export const SelectVariant: StoryObj = {
         onClick={() => {}}
       >
         <Interactive.Container border>
-          <span className="interactive-foreground">Unselected (heavy)</span>
+          <span>Unselected (heavy)</span>
         </Interactive.Container>
       </Interactive.Stateful>
     </div>

web/lib/opal/src/core/interactive/shared.css

@@ -21,9 +21,10 @@
   --interactive-easing: ease-in-out;
 }
 
-/* Base interactive surface */
+/* Base interactive surface — sets color directly so all descendants inherit. */
 .interactive {
   @apply cursor-pointer select-none;
+  color: var(--interactive-foreground);
   transition:
     background-color var(--interactive-duration) var(--interactive-easing),
     --interactive-foreground var(--interactive-duration)
@@ -43,14 +44,8 @@
   @apply border;
 }
 
-/* Utility classes — descendants opt in to parent-controlled foreground color.
-   No transition here — the parent interpolates the variables directly. */
-.interactive-foreground {
-  color: var(--interactive-foreground);
-}
-
-/* Icon foreground — reads from --interactive-foreground-icon, which defaults
-   to --interactive-foreground via the variant CSS rules. */
+/* Icon foreground — reads from --interactive-foreground-icon, which may differ
+   from --interactive-foreground (e.g. muted icons beside normal text). */
 .interactive-foreground-icon {
   color: var(--interactive-foreground-icon);
 }

web/lib/opal/src/core/interactive/simple/components.tsx

@@ -0,0 +1,100 @@
+import React from "react";
+import { Slot } from "@radix-ui/react-slot";
+import { cn } from "@opal/utils";
+import { useDisabled } from "@opal/core/disabled/components";
+
+// ---------------------------------------------------------------------------
+// Types
+// ---------------------------------------------------------------------------
+
+interface InteractiveSimpleProps
+  extends Omit<
+    React.HTMLAttributes<HTMLElement>,
+    "className" | "style" | "color"
+  > {
+  ref?: React.Ref<HTMLElement>;
+
+  /**
+   * Tailwind group class (e.g. `"group/Card"`) for `group-hover:*` utilities.
+   */
+  group?: string;
+
+  /**
+   * URL to navigate to when clicked. Passed through Slot to the child.
+   */
+  href?: string;
+
+  /**
+   * Link target (e.g. `"_blank"`). Only used when `href` is provided.
+   */
+  target?: string;
+}
+
+// ---------------------------------------------------------------------------
+// InteractiveSimple
+// ---------------------------------------------------------------------------
+
+/**
+ * Minimal interactive surface primitive.
+ *
+ * Provides cursor styling, click handling, disabled integration, and
+ * optional link/group support — but **no color or background styling**.
+ *
+ * Use this for elements that need interactivity (click, cursor, disabled)
+ * without participating in the Interactive color system.
+ *
+ * Uses Radix `Slot` — merges props onto a single child element without
+ * adding any DOM node.
+ *
+ * @example
+ * ```tsx
+ * <Interactive.Simple onClick={handleClick} group="group/Card">
+ *   <Card>...</Card>
+ * </Interactive.Simple>
+ * ```
+ */
+function InteractiveSimple({
+  ref,
+  group,
+  href,
+  target,
+  ...props
+}: InteractiveSimpleProps) {
+  const { isDisabled, allowClick } = useDisabled();
+
+  const classes = cn(
+    "cursor-pointer select-none",
+    isDisabled && "cursor-not-allowed",
+    !props.onClick && !href && "!cursor-default !select-auto",
+    group
+  );
+
+  const { onClick, ...slotProps } = props;
+
+  const linkAttrs = href
+    ? {
+        href: isDisabled ? undefined : href,
+        target,
+        rel: target === "_blank" ? "noopener noreferrer" : undefined,
+      }
+    : {};
+
+  return (
+    <Slot
+      ref={ref}
+      className={classes}
+      aria-disabled={isDisabled || undefined}
+      {...linkAttrs}
+      {...slotProps}
+      onClick={
+        isDisabled && !allowClick
+          ? href
+            ? (e: React.MouseEvent) => e.preventDefault()
+            : undefined
+          : onClick
+      }
+    />
+  );
+}
+
+export { InteractiveSimple, type InteractiveSimpleProps };

web/lib/opal/src/core/interactive/stateful/README.md

@@ -8,7 +8,7 @@ Stateful interactive surface primitive for elements that maintain a value state
 
 | Prop | Type | Default | Description |
 |------|------|---------|-------------|
-| `variant` | `"select-light" \| "select-heavy" \| "select-tinted" \| "select-filter" \| "sidebar"` | `"select-heavy"` | Color variant |
+| `variant` | `"select-light" \| "select-heavy" \| "select-card" \| "select-tinted" \| "select-filter" \| "sidebar-heavy" \| "sidebar-light"` | `"select-heavy"` | Color variant |
 | `state` | `"empty" \| "filled" \| "selected"` | `"empty"` | Current value state |
 | `interaction` | `"rest" \| "hover" \| "active"` | `"rest"` | JS-controlled interaction override |
 | `group` | `string` | — | Tailwind group class for `group-hover:*` |
@@ -16,6 +16,16 @@ Stateful interactive surface primitive for elements that maintain a value state
 | `href` | `string` | — | URL for link behavior |
 | `target` | `string` | — | Link target (e.g. `"_blank"`) |
 
+## Variants
+
+- **`select-light`** — Transparent selected background. For inline toggles.
+- **`select-heavy`** — Tinted selected background (`action-link-01`). For list rows, model pickers, buttons.
+- **`select-card`** — Like `select-heavy`, but the filled state gets a visible background (`background-tint-00`) with neutral foreground. Designed for larger surfaces (cards) where background carries more of the visual distinction than foreground color alone.
+- **`select-tinted`** — Like `select-heavy` but with a tinted rest background (`background-tint-01`).
+- **`select-filter`** — Like `select-tinted` for empty/filled; selected state uses inverted backgrounds and inverted text.
+- **`sidebar-heavy`** — Sidebar navigation: muted when unselected, bold when selected.
+- **`sidebar-light`** — Sidebar navigation: uniformly muted across all states.
+
 ## State attribute
 
 Uses `data-interactive-state` (not `data-state`) to avoid conflicts with Radix UI, which injects its own `data-state` on trigger elements.

web/lib/opal/src/core/interactive/stateful/components.tsx

@@ -13,9 +13,11 @@ import type { ButtonType, WithoutStyles } from "@opal/types";
 type InteractiveStatefulVariant =
   | "select-light"
   | "select-heavy"
+  | "select-card"
   | "select-tinted"
   | "select-filter"
-  | "sidebar";
+  | "sidebar-heavy"
+  | "sidebar-light";
 type InteractiveStatefulState = "empty" | "filled" | "selected";
 type InteractiveStatefulInteraction = "rest" | "hover" | "active";
 
@@ -31,9 +33,11 @@ interface InteractiveStatefulProps
    *
    * - `"select-light"` — transparent selected background (for inline toggles)
    * - `"select-heavy"` — tinted selected background (for list rows, model pickers)
+   * - `"select-card"` — like select-heavy but filled state has a visible background (for cards/larger surfaces)
    * - `"select-tinted"` — like select-heavy but with a tinted rest background
    * - `"select-filter"` — like select-tinted for empty/filled; selected state uses inverted tint backgrounds and inverted text (for filter buttons)
-   * - `"sidebar"` — for sidebar navigation items
+   * - `"sidebar-heavy"` — sidebar navigation items: muted when unselected (text-03/text-02), bold when selected (text-04/text-03)
+   * - `"sidebar-light"` — sidebar navigation items: uniformly muted across all states (text-02/text-02)
    *
    * @default "select-heavy"
    */

web/lib/opal/src/core/interactive/stateful/styles.css

@@ -11,7 +11,7 @@
    Children read the variables with no independent transitions.
 
    State dimension: `data-interactive-state` = "empty" | "filled" | "selected"
-   Variant dimension: `data-interactive-variant` = "select-light" | "select-heavy" | "select-tinted" | "sidebar"
+   Variant dimension: `data-interactive-variant` = "select-light" | "select-heavy" | "select-card" | "select-tinted" | "select-filter" | "sidebar-heavy" | "sidebar-light"
 
    Interaction override: `data-interaction="hover"` and `data-interaction="active"`
    allow JS-controlled visual state overrides.
@@ -114,6 +114,108 @@
   --interactive-foreground-icon: var(--action-link-03);
 }
 
+/* ===========================================================================
+   Select-Card — like Select-Heavy but filled has a visible background.
+   Designed for larger surfaces (cards) where background carries more of
+   the visual distinction than foreground color alone.
+   =========================================================================== */
+
+/* ---------------------------------------------------------------------------
+   Select-Card — Empty
+   --------------------------------------------------------------------------- */
+.interactive[data-interactive-variant="select-card"][data-interactive-state="empty"] {
+  @apply bg-transparent;
+  --interactive-foreground: var(--text-04);
+  --interactive-foreground-icon: var(--text-03);
+}
+.interactive[data-interactive-variant="select-card"][data-interactive-state="empty"]:hover:not(
+    [data-disabled]
+  ),
+.interactive[data-interactive-variant="select-card"][data-interactive-state="empty"][data-interaction="hover"]:not(
+    [data-disabled]
+  ) {
+  @apply bg-background-tint-02;
+  --interactive-foreground-icon: var(--text-04);
+}
+.interactive[data-interactive-variant="select-card"][data-interactive-state="empty"]:active:not(
+    [data-disabled]
+  ),
+.interactive[data-interactive-variant="select-card"][data-interactive-state="empty"][data-interaction="active"]:not(
+    [data-disabled]
+  ) {
+  @apply bg-background-neutral-00;
+  --interactive-foreground: var(--text-05);
+  --interactive-foreground-icon: var(--text-05);
+}
+.interactive[data-interactive-variant="select-card"][data-interactive-state="empty"][data-disabled] {
+  @apply bg-transparent;
+  --interactive-foreground: var(--text-01);
+  --interactive-foreground-icon: var(--text-01);
+}
+
+/* ---------------------------------------------------------------------------
+   Select-Card — Filled (visible background, neutral foreground)
+   --------------------------------------------------------------------------- */
+.interactive[data-interactive-variant="select-card"][data-interactive-state="filled"] {
+  @apply bg-background-tint-00;
+  --interactive-foreground: var(--text-04);
+  --interactive-foreground-icon: var(--text-03);
+}
+.interactive[data-interactive-variant="select-card"][data-interactive-state="filled"]:hover:not(
+    [data-disabled]
+  ),
+.interactive[data-interactive-variant="select-card"][data-interactive-state="filled"][data-interaction="hover"]:not(
+    [data-disabled]
+  ) {
+  @apply bg-background-tint-02;
+  --interactive-foreground-icon: var(--text-04);
+}
+.interactive[data-interactive-variant="select-card"][data-interactive-state="filled"]:active:not(
+    [data-disabled]
+  ),
+.interactive[data-interactive-variant="select-card"][data-interactive-state="filled"][data-interaction="active"]:not(
+    [data-disabled]
+  ) {
+  @apply bg-background-tint-00;
+  --interactive-foreground: var(--text-05);
+  --interactive-foreground-icon: var(--text-05);
+}
+.interactive[data-interactive-variant="select-card"][data-interactive-state="filled"][data-disabled] {
+  @apply bg-transparent;
+  --interactive-foreground: var(--text-01);
+  --interactive-foreground-icon: var(--text-01);
+}
+
+/* ---------------------------------------------------------------------------
+   Select-Card — Selected
+   --------------------------------------------------------------------------- */
+.interactive[data-interactive-variant="select-card"][data-interactive-state="selected"] {
+  @apply bg-[var(--action-link-01)];
+  --interactive-foreground: var(--action-link-05);
+  --interactive-foreground-icon: var(--action-link-05);
+}
+.interactive[data-interactive-variant="select-card"][data-interactive-state="selected"]:hover:not(
+    [data-disabled]
+  ),
+.interactive[data-interactive-variant="select-card"][data-interactive-state="selected"][data-interaction="hover"]:not(
+    [data-disabled]
+  ) {
+  @apply bg-background-tint-02;
+}
+.interactive[data-interactive-variant="select-card"][data-interactive-state="selected"]:active:not(
+    [data-disabled]
+  ),
+.interactive[data-interactive-variant="select-card"][data-interactive-state="selected"][data-interaction="active"]:not(
+    [data-disabled]
+  ) {
+  @apply bg-background-tint-00;
+}
+.interactive[data-interactive-variant="select-card"][data-interactive-state="selected"][data-disabled] {
+  @apply bg-transparent;
+  --interactive-foreground: var(--action-link-03);
+  --interactive-foreground-icon: var(--action-link-03);
+}
+
 /* ===========================================================================
    Select-Light — identical to Select-Heavy except selected bg is transparent
    =========================================================================== */
@@ -392,49 +494,115 @@
 }
 
 /* ===========================================================================
-   Sidebar
+   Sidebar-Heavy
+
+   Not selected: muted (text-03 / icon text-02)
+   Selected: default (text-04 / icon text-03)
    =========================================================================== */
 
 /* ---------------------------------------------------------------------------
-   Sidebar — Empty
+   Sidebar-Heavy — Empty
    --------------------------------------------------------------------------- */
-.interactive[data-interactive-variant="sidebar"][data-interactive-state="empty"] {
+.interactive[data-interactive-variant="sidebar-heavy"][data-interactive-state="empty"] {
   @apply bg-transparent;
+  --interactive-foreground: var(--text-03);
+  --interactive-foreground-icon: var(--text-02);
 }
-.interactive[data-interactive-variant="sidebar"][data-interactive-state="empty"]:hover:not(
+.interactive[data-interactive-variant="sidebar-heavy"][data-interactive-state="empty"]:hover:not(
     [data-disabled]
   ),
-.interactive[data-interactive-variant="sidebar"][data-interactive-state="empty"][data-interaction="hover"]:not(
+.interactive[data-interactive-variant="sidebar-heavy"][data-interactive-state="empty"][data-interaction="hover"]:not(
     [data-disabled]
   ) {
   @apply bg-background-tint-03;
 }
 
 /* ---------------------------------------------------------------------------
-   Sidebar — Filled
+   Sidebar-Heavy — Filled
    --------------------------------------------------------------------------- */
-.interactive[data-interactive-variant="sidebar"][data-interactive-state="filled"] {
+.interactive[data-interactive-variant="sidebar-heavy"][data-interactive-state="filled"] {
   @apply bg-transparent;
+  --interactive-foreground: var(--text-03);
+  --interactive-foreground-icon: var(--text-02);
 }
-.interactive[data-interactive-variant="sidebar"][data-interactive-state="filled"]:hover:not(
+.interactive[data-interactive-variant="sidebar-heavy"][data-interactive-state="filled"]:hover:not(
     [data-disabled]
   ),
-.interactive[data-interactive-variant="sidebar"][data-interactive-state="filled"][data-interaction="hover"]:not(
+.interactive[data-interactive-variant="sidebar-heavy"][data-interactive-state="filled"][data-interaction="hover"]:not(
     [data-disabled]
   ) {
   @apply bg-background-tint-03;
 }
 
 /* ---------------------------------------------------------------------------
-   Sidebar — Selected
+   Sidebar-Heavy — Selected
    --------------------------------------------------------------------------- */
-.interactive[data-interactive-variant="sidebar"][data-interactive-state="selected"] {
+.interactive[data-interactive-variant="sidebar-heavy"][data-interactive-state="selected"] {
   @apply bg-background-tint-00;
+  --interactive-foreground: var(--text-04);
+  --interactive-foreground-icon: var(--text-03);
 }
-.interactive[data-interactive-variant="sidebar"][data-interactive-state="selected"]:hover:not(
+.interactive[data-interactive-variant="sidebar-heavy"][data-interactive-state="selected"]:hover:not(
     [data-disabled]
   ),
-.interactive[data-interactive-variant="sidebar"][data-interactive-state="selected"][data-interaction="hover"]:not(
+.interactive[data-interactive-variant="sidebar-heavy"][data-interactive-state="selected"][data-interaction="hover"]:not(
+    [data-disabled]
+  ) {
+  @apply bg-background-tint-03;
+}
+
+/* ===========================================================================
+   Sidebar-Light
+
+   All states: prominence="muted-2x" colors (text-02 / icon text-02)
+   =========================================================================== */
+
+/* ---------------------------------------------------------------------------
+   Sidebar-Light — Empty
+   --------------------------------------------------------------------------- */
+.interactive[data-interactive-variant="sidebar-light"][data-interactive-state="empty"] {
+  @apply bg-transparent;
+  --interactive-foreground: var(--text-02);
+  --interactive-foreground-icon: var(--text-02);
+}
+.interactive[data-interactive-variant="sidebar-light"][data-interactive-state="empty"]:hover:not(
+    [data-disabled]
+  ),
+.interactive[data-interactive-variant="sidebar-light"][data-interactive-state="empty"][data-interaction="hover"]:not(
+    [data-disabled]
+  ) {
+  @apply bg-background-tint-03;
+}
+
+/* ---------------------------------------------------------------------------
+   Sidebar-Light — Filled
+   --------------------------------------------------------------------------- */
+.interactive[data-interactive-variant="sidebar-light"][data-interactive-state="filled"] {
+  @apply bg-transparent;
+  --interactive-foreground: var(--text-02);
+  --interactive-foreground-icon: var(--text-02);
+}
+.interactive[data-interactive-variant="sidebar-light"][data-interactive-state="filled"]:hover:not(
+    [data-disabled]
+  ),
+.interactive[data-interactive-variant="sidebar-light"][data-interactive-state="filled"][data-interaction="hover"]:not(
+    [data-disabled]
+  ) {
+  @apply bg-background-tint-03;
+}
+
+/* ---------------------------------------------------------------------------
+   Sidebar-Light — Selected
+   --------------------------------------------------------------------------- */
+.interactive[data-interactive-variant="sidebar-light"][data-interactive-state="selected"] {
+  @apply bg-background-tint-00;
+  --interactive-foreground: var(--text-02);
+  --interactive-foreground-icon: var(--text-02);
+}
+.interactive[data-interactive-variant="sidebar-light"][data-interactive-state="selected"]:hover:not(
+    [data-disabled]
+  ),
+.interactive[data-interactive-variant="sidebar-light"][data-interactive-state="selected"][data-interaction="hover"]:not(
     [data-disabled]
   ) {
   @apply bg-background-tint-03;

web/lib/opal/src/core/interactive/stateless/components.tsx

@@ -10,7 +10,7 @@ import type { ButtonType, WithoutStyles } from "@opal/types";
 // Types
 // ---------------------------------------------------------------------------
 
-type InteractiveStatelessVariant = "none" | "default" | "action" | "danger";
+type InteractiveStatelessVariant = "default" | "action" | "danger";
 type InteractiveStatelessProminence =
   | "primary"
   | "secondary"
@@ -108,8 +108,8 @@ function InteractiveStateless({
   );
 
   const dataAttrs = {
-    "data-interactive-variant": variant !== "none" ? variant : undefined,
-    "data-interactive-prominence": variant !== "none" ? prominence : undefined,
+    "data-interactive-variant": variant,
+    "data-interactive-prominence": prominence,
     "data-interaction": interaction !== "rest" ? interaction : undefined,
     "data-disabled": isDisabled ? "true" : undefined,
     "aria-disabled": isDisabled || undefined,

web/lib/opal/src/layouts/cards/header-layout/CardHeaderLayout.stories.tsx

@@ -0,0 +1,158 @@
+import type { Meta, StoryObj } from "@storybook/react";
+import { CardHeaderLayout } from "@opal/layouts";
+import { Button } from "@opal/components";
+import {
+  SvgArrowExchange,
+  SvgCheckSquare,
+  SvgGlobe,
+  SvgSettings,
+  SvgUnplug,
+} from "@opal/icons";
+import * as TooltipPrimitive from "@radix-ui/react-tooltip";
+import type { Decorator } from "@storybook/react";
+
+const withTooltipProvider: Decorator = (Story) => (
+  <TooltipPrimitive.Provider>
+    <Story />
+  </TooltipPrimitive.Provider>
+);
+
+const meta = {
+  title: "Layouts/CardHeaderLayout",
+  component: CardHeaderLayout,
+  tags: ["autodocs"],
+  decorators: [withTooltipProvider],
+  parameters: {
+    layout: "centered",
+  },
+} satisfies Meta<typeof CardHeaderLayout>;
+
+export default meta;
+
+type Story = StoryObj<typeof meta>;
+
+// ---------------------------------------------------------------------------
+// Stories
+// ---------------------------------------------------------------------------
+
+export const Default: Story = {
+  render: () => (
+    <div className="w-[28rem] border rounded-16">
+      <CardHeaderLayout
+        sizePreset="main-ui"
+        variant="section"
+        icon={SvgGlobe}
+        title="Google Search"
+        description="Web search provider"
+        rightChildren={
+          <Button prominence="tertiary" rightIcon={SvgArrowExchange}>
+            Connect
+          </Button>
+        }
+      />
+    </div>
+  ),
+};
+
+export const WithBothSlots: Story = {
+  render: () => (
+    <div className="w-[28rem] border rounded-16">
+      <CardHeaderLayout
+        sizePreset="main-ui"
+        variant="section"
+        icon={SvgGlobe}
+        title="Google Search"
+        description="Currently the default provider."
+        rightChildren={
+          <Button variant="action" prominence="tertiary" icon={SvgCheckSquare}>
+            Current Default
+          </Button>
+        }
+        bottomRightChildren={
+          <>
+            <Button
+              icon={SvgUnplug}
+              tooltip="Disconnect"
+              prominence="tertiary"
+              size="sm"
+            />
+            <Button
+              icon={SvgSettings}
+              tooltip="Edit"
+              prominence="tertiary"
+              size="sm"
+            />
+          </>
+        }
+      />
+    </div>
+  ),
+};
+
+export const RightChildrenOnly: Story = {
+  render: () => (
+    <div className="w-[28rem] border rounded-16">
+      <CardHeaderLayout
+        sizePreset="main-ui"
+        variant="section"
+        icon={SvgGlobe}
+        title="OpenAI"
+        description="Not configured"
+        rightChildren={
+          <Button prominence="tertiary" rightIcon={SvgArrowExchange}>
+            Connect
+          </Button>
+        }
+      />
+    </div>
+  ),
+};
+
+export const NoRightChildren: Story = {
+  render: () => (
+    <div className="w-[28rem] border rounded-16">
+      <CardHeaderLayout
+        sizePreset="main-ui"
+        variant="section"
+        icon={SvgGlobe}
+        title="Section Header"
+        description="No actions on the right."
+      />
+    </div>
+  ),
+};
+
+export const LongContent: Story = {
+  render: () => (
+    <div className="w-[28rem] border rounded-16">
+      <CardHeaderLayout
+        sizePreset="main-ui"
+        variant="section"
+        icon={SvgGlobe}
+        title="Very Long Provider Name That Should Truncate"
+        description="This is a much longer description that tests how the layout handles overflow when the content area needs to shrink."
+        rightChildren={
+          <Button variant="action" prominence="tertiary" icon={SvgCheckSquare}>
+            Current Default
+          </Button>
+        }
+        bottomRightChildren={
+          <>
+            <Button
+              icon={SvgUnplug}
+              prominence="tertiary"
+              size="sm"
+              tooltip="Disconnect"
+            />
+            <Button
+              icon={SvgSettings}
+              prominence="tertiary"
+              size="sm"
+              tooltip="Edit"
+            />
+          </>
+        }
+      />
+    </div>
+  ),
+};

web/lib/opal/src/layouts/cards/header-layout/README.md

@@ -0,0 +1,94 @@
+# CardHeaderLayout
+
+**Import:** `import { CardHeaderLayout, type CardHeaderLayoutProps } from "@opal/layouts";`
+
+A card header layout that pairs a [`Content`](../../content/README.md) block with a right-side column of vertically stacked children.
+
+## Why CardHeaderLayout?
+
+[`ContentAction`](../../content-action/README.md) provides a single `rightChildren` slot. Card headers typically need two distinct right-side regions — a primary action on top and secondary actions on the bottom. `CardHeaderLayout` provides this with `rightChildren` and `bottomRightChildren` slots, with no padding or gap between them so the caller has full control over spacing.
+
+## Props
+
+Inherits **all** props from [`Content`](../../content/README.md) (icon, title, description, sizePreset, variant, etc.) plus:
+
+| Prop | Type | Default | Description |
+|---|---|---|---|
+| `rightChildren` | `ReactNode` | `undefined` | Content rendered to the right of the Content block (top of right column). |
+| `bottomRightChildren` | `ReactNode` | `undefined` | Content rendered below `rightChildren` in the same column. Laid out as `flex flex-row`. |
+
+## Layout Structure
+
+```
+┌──────────────────────────────────────────────────────┐
+│ [Content (p-2, self-start)]  [rightChildren]         │
+│  icon + title + description  [bottomRightChildren]   │
+└──────────────────────────────────────────────────────┘
+```
+
+- Outer wrapper: `flex flex-row items-stretch w-full`
+- Content area: `flex-1 min-w-0 self-start p-2` — top-aligned with fixed padding
+- Right column: `flex flex-col items-end justify-between shrink-0` — no padding, no gap
+- `bottomRightChildren` wrapper: `flex flex-row` — lays children out horizontally
+
+The right column uses `justify-between` so when both slots are present, `rightChildren` sits at the top and `bottomRightChildren` at the bottom.
+
+## Usage
+
+### Card with primary and secondary actions
+
+```tsx
+import { CardHeaderLayout } from "@opal/layouts";
+import { Button } from "@opal/components";
+import { SvgGlobe, SvgSettings, SvgUnplug, SvgCheckSquare } from "@opal/icons";
+
+<CardHeaderLayout
+  icon={SvgGlobe}
+  title="Google Search"
+  description="Web search provider"
+  sizePreset="main-ui"
+  variant="section"
+  rightChildren={
+    <Button icon={SvgCheckSquare} variant="action" prominence="tertiary">
+      Current Default
+    </Button>
+  }
+  bottomRightChildren={
+    <>
+      <Button icon={SvgUnplug} size="sm" prominence="tertiary" tooltip="Disconnect" />
+      <Button icon={SvgSettings} size="sm" prominence="tertiary" tooltip="Edit" />
+    </>
+  }
+/>
+```
+
+### Card with only a connect action
+
+```tsx
+<CardHeaderLayout
+  icon={SvgCloud}
+  title="OpenAI"
+  description="Not configured"
+  sizePreset="main-ui"
+  variant="section"
+  rightChildren={
+    <Button rightIcon={SvgArrowExchange} prominence="tertiary">
+      Connect
+    </Button>
+  }
+/>
+```
+
+### No right children
+
+```tsx
+<CardHeaderLayout
+  icon={SvgInfo}
+  title="Section Header"
+  description="Description text"
+  sizePreset="main-content"
+  variant="section"
+/>
+```
+
+When both `rightChildren` and `bottomRightChildren` are omitted, the component renders only the padded `Content`.

web/lib/opal/src/layouts/cards/header-layout/components.tsx

@@ -0,0 +1,73 @@
+import { Content, type ContentProps } from "@opal/layouts/content/components";
+
+// ---------------------------------------------------------------------------
+// Types
+// ---------------------------------------------------------------------------
+
+type CardHeaderLayoutProps = ContentProps & {
+  /** Content rendered to the right of the Content block. */
+  rightChildren?: React.ReactNode;
+
+  /** Content rendered below `rightChildren` in the same column. */
+  bottomRightChildren?: React.ReactNode;
+};
+
+// ---------------------------------------------------------------------------
+// CardHeaderLayout
+// ---------------------------------------------------------------------------
+
+/**
+ * A card header layout that pairs a {@link Content} block (with `p-2`)
+ * with a right-side column.
+ *
+ * The right column contains two vertically stacked slots —
+ * `rightChildren` on top, `bottomRightChildren` below — with no
+ * padding or gap between them.
+ *
+ * @example
+ * ```tsx
+ * <CardHeaderLayout
+ *   icon={SvgGlobe}
+ *   title="Google"
+ *   description="Search engine"
+ *   sizePreset="main-ui"
+ *   variant="section"
+ *   rightChildren={<Button>Connect</Button>}
+ *   bottomRightChildren={
+ *     <>
+ *       <Button icon={SvgUnplug} size="sm" prominence="tertiary" />
+ *       <Button icon={SvgSettings} size="sm" prominence="tertiary" />
+ *     </>
+ *   }
+ * />
+ * ```
+ */
+function CardHeaderLayout({
+  rightChildren,
+  bottomRightChildren,
+  ...contentProps
+}: CardHeaderLayoutProps) {
+  const hasRight = rightChildren || bottomRightChildren;
+
+  return (
+    <div className="flex flex-row items-stretch w-full">
+      <div className="flex-1 min-w-0 self-start p-2">
+        <Content {...contentProps} />
+      </div>
+      {hasRight && (
+        <div className="flex flex-col items-end shrink-0">
+          {rightChildren && <div className="flex-1">{rightChildren}</div>}
+          {bottomRightChildren && (
+            <div className="flex flex-row">{bottomRightChildren}</div>
+          )}
+        </div>
+      )}
+    </div>
+  );
+}
+
+// ---------------------------------------------------------------------------
+// Exports
+// ---------------------------------------------------------------------------
+
+export { CardHeaderLayout, type CardHeaderLayoutProps };

web/lib/opal/src/layouts/content/ContentLg.tsx

@@ -4,10 +4,8 @@ import { Button } from "@opal/components/buttons/button/components";
 import type { ContainerSizeVariants } from "@opal/types";
 import SvgEdit from "@opal/icons/edit";
 import type { IconFunctionComponent, RichStr } from "@opal/types";
-import {
-  resolveStr,
-  toPlainString,
-} from "@opal/components/text/InlineMarkdown";
+import { Text, type TextFont } from "@opal/components/text/components";
+import { toPlainString } from "@opal/components/text/InlineMarkdown";
 import { cn } from "@opal/utils";
 import { useState } from "react";
 
@@ -24,8 +22,8 @@ interface ContentLgPresetConfig {
   iconContainerPadding: string;
   /** Gap between icon container and content (CSS value). */
   gap: string;
-  /** Tailwind font class for the title. */
-  titleFont: string;
+  /** Opal font name for the title (without `font-` prefix). */
+  titleFont: TextFont;
   /** Title line-height — also used as icon container min-height (CSS value). */
   lineHeight: string;
   /** Button `size` prop for the edit button. Uses the shared `SizeVariant` scale. */
@@ -53,9 +51,6 @@ interface ContentLgProps {
   /** Size preset. Default: `"headline"`. */
   sizePreset?: ContentLgSizePreset;
 
-  /** When `true`, the title color hooks into `Interactive`'s `--interactive-foreground` variable. */
-  withInteractive?: boolean;
-
   /** Ref forwarded to the root `<div>`. */
   ref?: React.Ref<HTMLDivElement>;
 }
@@ -69,7 +64,7 @@ const CONTENT_LG_PRESETS: Record<ContentLgSizePreset, ContentLgPresetConfig> = {
     iconSize: "2rem",
     iconContainerPadding: "p-0.5",
     gap: "0.25rem",
-    titleFont: "font-heading-h2",
+    titleFont: "heading-h2",
     lineHeight: "2.25rem",
     editButtonSize: "md",
     editButtonPadding: "p-1",
@@ -78,7 +73,7 @@ const CONTENT_LG_PRESETS: Record<ContentLgSizePreset, ContentLgPresetConfig> = {
     iconSize: "1.25rem",
     iconContainerPadding: "p-1",
     gap: "0rem",
-    titleFont: "font-heading-h3-muted",
+    titleFont: "heading-h3-muted",
     lineHeight: "1.75rem",
     editButtonSize: "sm",
     editButtonPadding: "p-0.5",
@@ -96,7 +91,6 @@ function ContentLg({
   description,
   editable,
   onTitleChange,
-  withInteractive,
   ref,
 }: ContentLgProps) {
   const [editing, setEditing] = useState(false);
@@ -116,12 +110,7 @@ function ContentLg({
   }
 
   return (
-    <div
-      ref={ref}
-      className="opal-content-lg"
-      data-interactive={withInteractive || undefined}
-      style={{ gap: config.gap }}
-    >
+    <div ref={ref} className="opal-content-lg" style={{ gap: config.gap }}>
       {Icon && (
         <div
           className={cn(
@@ -142,14 +131,17 @@ function ContentLg({
           {editing ? (
             <div className="opal-content-lg-input-sizer">
               <span
-                className={cn("opal-content-lg-input-mirror", config.titleFont)}
+                className={cn(
+                  "opal-content-lg-input-mirror",
+                  `font-${config.titleFont}`
+                )}
               >
                 {editValue || "\u00A0"}
               </span>
               <input
                 className={cn(
                   "opal-content-lg-input",
-                  config.titleFont,
+                  `font-${config.titleFont}`,
                   "text-text-04"
                 )}
                 value={editValue}
@@ -169,19 +161,15 @@ function ContentLg({
               />
             </div>
           ) : (
-            <span
-              className={cn(
-                "opal-content-lg-title",
-                config.titleFont,
-                "text-text-04",
-                editable && "cursor-pointer"
-              )}
-              onClick={editable ? startEditing : undefined}
-              style={{ height: config.lineHeight }}
+            <Text
+              font={config.titleFont}
+              color="inherit"
+              maxLines={1}
               title={toPlainString(title)}
+              onClick={editable ? startEditing : undefined}
             >
-              {resolveStr(title)}
-            </span>
+              {title}
+            </Text>
           )}
 
           {editable && !editing && (
@@ -204,8 +192,10 @@ function ContentLg({
         </div>
 
         {description && toPlainString(description) && (
-          <div className="opal-content-lg-description font-secondary-body text-text-03">
-            {resolveStr(description)}
+          <div className="opal-content-lg-description">
+            <Text font="secondary-body" color="text-03" as="p">
+              {description}
+            </Text>
           </div>
         )}
       </div>

web/lib/opal/src/layouts/content/ContentMd.tsx

@@ -8,10 +8,8 @@ import SvgAlertTriangle from "@opal/icons/alert-triangle";
 import SvgEdit from "@opal/icons/edit";
 import SvgXOctagon from "@opal/icons/x-octagon";
 import type { IconFunctionComponent, RichStr } from "@opal/types";
-import {
-  resolveStr,
-  toPlainString,
-} from "@opal/components/text/InlineMarkdown";
+import { Text, type TextFont } from "@opal/components/text/components";
+import { toPlainString } from "@opal/components/text/InlineMarkdown";
 import { cn } from "@opal/utils";
 import { useRef, useState } from "react";
 
@@ -23,16 +21,18 @@ type ContentMdSizePreset = "main-content" | "main-ui" | "secondary";
 
 type ContentMdAuxIcon = "info-gray" | "info-blue" | "warning" | "error";
 
+type ContentMdSuffix = "optional" | (string & {});
+
 interface ContentMdPresetConfig {
   iconSize: string;
   iconContainerPadding: string;
   iconColorClass: string;
-  titleFont: string;
+  titleFont: TextFont;
   lineHeight: string;
   /** Button `size` prop for the edit button. Uses the shared `SizeVariant` scale. */
   editButtonSize: ContainerSizeVariants;
   editButtonPadding: string;
-  optionalFont: string;
+  optionalFont: TextFont;
   /** Aux icon size = lineHeight − 2 × p-0.5. */
   auxIconSize: string;
   /** Left indent for the description so it aligns with the title (past the icon). */
@@ -55,11 +55,11 @@ interface ContentMdProps {
   /** Called when the user commits an edit. */
   onTitleChange?: (newTitle: string) => void;
 
-  /** When `true`, renders "(Optional)" beside the title. */
-  optional?: boolean;
-
-  /** Custom muted suffix rendered beside the title. */
-  titleSuffix?: string;
+  /**
+   * Muted suffix rendered beside the title.
+   * Use `"optional"` for the standard "(Optional)" label, or pass any string.
+   */
+  suffix?: ContentMdSuffix;
 
   /** Auxiliary status icon rendered beside the title. */
   auxIcon?: ContentMdAuxIcon;
@@ -70,18 +70,6 @@ interface ContentMdProps {
   /** Size preset. Default: `"main-ui"`. */
   sizePreset?: ContentMdSizePreset;
 
-  /** When `true`, the title color hooks into `Interactive`'s `--interactive-foreground` variable. */
-  withInteractive?: boolean;
-
-  /** Optional class name applied to the title element. */
-  titleClassName?: string;
-
-  /** Optional class name applied to the icon element. */
-  iconClassName?: string;
-
-  /** Content rendered below the description, indented to align with it. */
-  bottomChildren?: React.ReactNode;
-
   /** Ref forwarded to the root `<div>`. */
   ref?: React.Ref<HTMLDivElement>;
 }
@@ -95,11 +83,11 @@ const CONTENT_MD_PRESETS: Record<ContentMdSizePreset, ContentMdPresetConfig> = {
     iconSize: "1rem",
     iconContainerPadding: "p-1",
     iconColorClass: "text-text-04",
-    titleFont: "font-main-content-emphasis",
+    titleFont: "main-content-emphasis",
     lineHeight: "1.5rem",
     editButtonSize: "sm",
     editButtonPadding: "p-0",
-    optionalFont: "font-main-content-muted",
+    optionalFont: "main-content-muted",
     auxIconSize: "1.25rem",
     descriptionIndent: "1.625rem",
   },
@@ -107,11 +95,11 @@ const CONTENT_MD_PRESETS: Record<ContentMdSizePreset, ContentMdPresetConfig> = {
     iconSize: "1rem",
     iconContainerPadding: "p-0.5",
     iconColorClass: "text-text-03",
-    titleFont: "font-main-ui-action",
+    titleFont: "main-ui-action",
     lineHeight: "1.25rem",
     editButtonSize: "xs",
     editButtonPadding: "p-0",
-    optionalFont: "font-main-ui-muted",
+    optionalFont: "main-ui-muted",
     auxIconSize: "1rem",
     descriptionIndent: "1.375rem",
   },
@@ -119,11 +107,11 @@ const CONTENT_MD_PRESETS: Record<ContentMdSizePreset, ContentMdPresetConfig> = {
     iconSize: "0.75rem",
     iconContainerPadding: "p-0.5",
     iconColorClass: "text-text-04",
-    titleFont: "font-secondary-action",
+    titleFont: "secondary-action",
     lineHeight: "1rem",
     editButtonSize: "2xs",
     editButtonPadding: "p-0",
-    optionalFont: "font-secondary-action",
+    optionalFont: "secondary-action",
     auxIconSize: "0.75rem",
     descriptionIndent: "1.125rem",
   },
@@ -149,15 +137,10 @@ function ContentMd({
   description,
   editable,
   onTitleChange,
-  optional,
-  titleSuffix,
+  suffix,
   auxIcon,
   tag,
   sizePreset = "main-ui",
-  withInteractive,
-  titleClassName,
-  iconClassName,
-  bottomChildren,
   ref,
 }: ContentMdProps) {
   const [editing, setEditing] = useState(false);
@@ -178,11 +161,7 @@ function ContentMd({
   }
 
   return (
-    <div
-      ref={ref}
-      className="opal-content-md"
-      data-interactive={withInteractive || undefined}
-    >
+    <div ref={ref} className="opal-content-md">
       <div
         className="opal-content-md-header"
         data-editing={editing || undefined}
@@ -196,11 +175,7 @@ function ContentMd({
             style={{ minHeight: config.lineHeight }}
           >
             <Icon
-              className={cn(
-                "opal-content-md-icon",
-                config.iconColorClass,
-                iconClassName
-              )}
+              className={cn("opal-content-md-icon", config.iconColorClass)}
               style={{ width: config.iconSize, height: config.iconSize }}
             />
           </div>
@@ -210,7 +185,10 @@ function ContentMd({
           {editing ? (
             <div className="opal-content-md-input-sizer">
               <span
-                className={cn("opal-content-md-input-mirror", config.titleFont)}
+                className={cn(
+                  "opal-content-md-input-mirror",
+                  `font-${config.titleFont}`
+                )}
               >
                 {editValue || "\u00A0"}
               </span>
@@ -218,7 +196,7 @@ function ContentMd({
                 ref={inputRef}
                 className={cn(
                   "opal-content-md-input",
-                  config.titleFont,
+                  `font-${config.titleFont}`,
                   "text-text-04"
                 )}
                 value={editValue}
@@ -238,29 +216,21 @@ function ContentMd({
               />
             </div>
           ) : (
-            <span
-              className={cn(
-                "opal-content-md-title",
-                config.titleFont,
-                "text-text-04",
-                editable && "cursor-pointer",
-                titleClassName
-              )}
+            <Text
+              font={config.titleFont}
+              color="inherit"
+              maxLines={1}
               title={toPlainString(title)}
               onClick={editable ? startEditing : undefined}
-              style={{ height: config.lineHeight }}
             >
-              {resolveStr(title)}
-            </span>
+              {title}
+            </Text>
           )}
 
-          {(optional || titleSuffix) && (
-            <span
-              className={cn(config.optionalFont, "text-text-03 shrink-0")}
-              style={{ height: config.lineHeight }}
-            >
-              {titleSuffix ?? "(Optional)"}
-            </span>
+          {suffix && (
+            <Text font={config.optionalFont} color="text-03">
+              {suffix === "optional" ? "(Optional)" : suffix}
+            </Text>
           )}
 
           {auxIcon &&
@@ -306,17 +276,12 @@ function ContentMd({
 
       {description && toPlainString(description) && (
         <div
-          className="opal-content-md-description font-secondary-body text-text-03"
+          className="opal-content-md-description"
           style={Icon ? { paddingLeft: config.descriptionIndent } : undefined}
         >
-          {resolveStr(description)}
-        </div>
-      )}
-      {bottomChildren && (
-        <div
-          style={Icon ? { paddingLeft: config.descriptionIndent } : undefined}
-        >
-          {bottomChildren}
+          <Text font="secondary-body" color="text-03" as="p">
+            {description}
+          </Text>
         </div>
       )}
     </div>
@@ -327,5 +292,6 @@ export {
   ContentMd,
   type ContentMdProps,
   type ContentMdSizePreset,
+  type ContentMdSuffix,
   type ContentMdAuxIcon,
 };

web/lib/opal/src/layouts/content/ContentSm.tsx

@@ -1,10 +1,8 @@
 "use client";
 
 import type { IconFunctionComponent, RichStr } from "@opal/types";
-import {
-  resolveStr,
-  toPlainString,
-} from "@opal/components/text/InlineMarkdown";
+import { Text, type TextFont } from "@opal/components/text/components";
+import { toPlainString } from "@opal/components/text/InlineMarkdown";
 import { cn } from "@opal/utils";
 
 // ---------------------------------------------------------------------------
@@ -13,15 +11,15 @@ import { cn } from "@opal/utils";
 
 type ContentSmSizePreset = "main-content" | "main-ui" | "secondary";
 type ContentSmOrientation = "vertical" | "inline" | "reverse";
-type ContentSmProminence = "default" | "muted" | "muted-2x";
+type ContentSmProminence = "default" | "muted";
 
 interface ContentSmPresetConfig {
   /** Icon width/height (CSS value). */
   iconSize: string;
   /** Tailwind padding class for the icon container. */
   iconContainerPadding: string;
-  /** Tailwind font class for the title. */
-  titleFont: string;
+  /** Font preset for the title. */
+  titleFont: TextFont;
   /** Title line-height — also used as icon container min-height (CSS value). */
   lineHeight: string;
   /** Gap between icon container and title (CSS value). */
@@ -45,9 +43,6 @@ interface ContentSmProps {
   /** Title prominence. Default: `"default"`. */
   prominence?: ContentSmProminence;
 
-  /** When `true`, the title color hooks into `Interactive`'s `--interactive-foreground` variable. */
-  withInteractive?: boolean;
-
   /** Ref forwarded to the root `<div>`. */
   ref?: React.Ref<HTMLDivElement>;
 }
@@ -60,21 +55,21 @@ const CONTENT_SM_PRESETS: Record<ContentSmSizePreset, ContentSmPresetConfig> = {
   "main-content": {
     iconSize: "1rem",
     iconContainerPadding: "p-1",
-    titleFont: "font-main-content-body",
+    titleFont: "main-content-body",
     lineHeight: "1.5rem",
     gap: "0.125rem",
   },
   "main-ui": {
     iconSize: "1rem",
     iconContainerPadding: "p-0.5",
-    titleFont: "font-main-ui-action",
+    titleFont: "main-ui-action",
     lineHeight: "1.25rem",
     gap: "0.25rem",
   },
   secondary: {
     iconSize: "0.75rem",
     iconContainerPadding: "p-0.5",
-    titleFont: "font-secondary-action",
+    titleFont: "secondary-action",
     lineHeight: "1rem",
     gap: "0.125rem",
   },
@@ -90,7 +85,6 @@ function ContentSm({
   sizePreset = "main-ui",
   orientation = "inline",
   prominence = "default",
-  withInteractive,
   ref,
 }: ContentSmProps) {
   const config = CONTENT_SM_PRESETS[sizePreset];
@@ -101,7 +95,6 @@ function ContentSm({
       className="opal-content-sm"
       data-orientation={orientation}
       data-prominence={prominence}
-      data-interactive={withInteractive || undefined}
       style={{ gap: config.gap }}
     >
       {Icon && (
@@ -119,13 +112,14 @@ function ContentSm({
         </div>
       )}
 
-      <span
-        className={cn("opal-content-sm-title", config.titleFont)}
-        style={{ height: config.lineHeight }}
+      <Text
+        font={config.titleFont}
+        color="inherit"
+        maxLines={1}
         title={toPlainString(title)}
       >
-        {resolveStr(title)}
-      </span>
+        {title}
+      </Text>
     </div>
   );
 }

web/lib/opal/src/layouts/content/ContentXl.tsx

@@ -4,10 +4,8 @@ import { Button } from "@opal/components/buttons/button/components";
 import type { ContainerSizeVariants } from "@opal/types";
 import SvgEdit from "@opal/icons/edit";
 import type { IconFunctionComponent, RichStr } from "@opal/types";
-import {
-  resolveStr,
-  toPlainString,
-} from "@opal/components/text/InlineMarkdown";
+import { Text, type TextFont } from "@opal/components/text/components";
+import { toPlainString } from "@opal/components/text/InlineMarkdown";
 import { cn } from "@opal/utils";
 import { useState } from "react";
 
@@ -30,8 +28,8 @@ interface ContentXlPresetConfig {
   moreIcon2Size: string;
   /** Tailwind padding class for the more-icon-2 container. */
   moreIcon2ContainerPadding: string;
-  /** Tailwind font class for the title. */
-  titleFont: string;
+  /** Opal font name for the title (without `font-` prefix). */
+  titleFont: TextFont;
   /** Title line-height — also used as icon container min-height (CSS value). */
   lineHeight: string;
   /** Button `size` prop for the edit button. Uses the shared `SizeVariant` scale. */
@@ -65,9 +63,6 @@ interface ContentXlProps {
   /** Optional tertiary icon rendered in the icon row. */
   moreIcon2?: IconFunctionComponent;
 
-  /** When `true`, the title color hooks into `Interactive`'s `--interactive-foreground` variable. */
-  withInteractive?: boolean;
-
   /** Ref forwarded to the root `<div>`. */
   ref?: React.Ref<HTMLDivElement>;
 }
@@ -84,7 +79,7 @@ const CONTENT_XL_PRESETS: Record<ContentXlSizePreset, ContentXlPresetConfig> = {
     moreIcon1ContainerPadding: "p-0.5",
     moreIcon2Size: "2rem",
     moreIcon2ContainerPadding: "p-0.5",
-    titleFont: "font-heading-h2",
+    titleFont: "heading-h2",
     lineHeight: "2.25rem",
     editButtonSize: "md",
     editButtonPadding: "p-1",
@@ -96,7 +91,7 @@ const CONTENT_XL_PRESETS: Record<ContentXlSizePreset, ContentXlPresetConfig> = {
     moreIcon1ContainerPadding: "p-0.5",
     moreIcon2Size: "1.5rem",
     moreIcon2ContainerPadding: "p-0.5",
-    titleFont: "font-heading-h3",
+    titleFont: "heading-h3",
     lineHeight: "1.75rem",
     editButtonSize: "sm",
     editButtonPadding: "p-0.5",
@@ -116,7 +111,6 @@ function ContentXl({
   onTitleChange,
   moreIcon1: MoreIcon1,
   moreIcon2: MoreIcon2,
-  withInteractive,
   ref,
 }: ContentXlProps) {
   const [editing, setEditing] = useState(false);
@@ -136,11 +130,7 @@ function ContentXl({
   }
 
   return (
-    <div
-      ref={ref}
-      className="opal-content-xl"
-      data-interactive={withInteractive || undefined}
-    >
+    <div ref={ref} className="opal-content-xl">
       {(Icon || MoreIcon1 || MoreIcon2) && (
         <div className="opal-content-xl-icon-row">
           {Icon && (
@@ -199,14 +189,17 @@ function ContentXl({
           {editing ? (
             <div className="opal-content-xl-input-sizer">
               <span
-                className={cn("opal-content-xl-input-mirror", config.titleFont)}
+                className={cn(
+                  "opal-content-xl-input-mirror",
+                  `font-${config.titleFont}`
+                )}
               >
                 {editValue || "\u00A0"}
               </span>
               <input
                 className={cn(
                   "opal-content-xl-input",
-                  config.titleFont,
+                  `font-${config.titleFont}`,
                   "text-text-04"
                 )}
                 value={editValue}
@@ -226,19 +219,15 @@ function ContentXl({
               />
             </div>
           ) : (
-            <span
-              className={cn(
-                "opal-content-xl-title",
-                config.titleFont,
-                "text-text-04",
-                editable && "cursor-pointer"
-              )}
-              onClick={editable ? startEditing : undefined}
-              style={{ height: config.lineHeight }}
+            <Text
+              font={config.titleFont}
+              color="inherit"
+              maxLines={1}
               title={toPlainString(title)}
+              onClick={editable ? startEditing : undefined}
             >
-              {resolveStr(title)}
-            </span>
+              {title}
+            </Text>
           )}
 
           {editable && !editing && (
@@ -261,8 +250,10 @@ function ContentXl({
         </div>
 
         {description && toPlainString(description) && (
-          <div className="opal-content-xl-description font-secondary-body text-text-03">
-            {resolveStr(description)}
+          <div className="opal-content-xl-description">
+            <Text font="secondary-body" color="text-03" as="p">
+              {description}
+            </Text>
           </div>
         )}
       </div>

web/lib/opal/src/layouts/content/components.tsx

@@ -1,39 +1,3 @@
-// ---------------------------------------------------------------------------
-// NOTE (@raunakab): Why Content uses resolveStr() instead of <Text>
-//
-// Content sub-components (ContentXl, ContentLg, ContentMd, ContentSm) render
-// titles and descriptions inside styled <span> elements that carry CSS classes
-// (e.g., `.opal-content-md-title`) for:
-//
-//   1. Truncation — `-webkit-box` + `-webkit-line-clamp` for single-line
-//      clamping with ellipsis. This requires the text to be a DIRECT child
-//      of the `-webkit-box` element. Wrapping it in a child <span> (which
-//      is what <Text> renders) breaks the clamping behavior.
-//
-//   2. Pixel-exact sizing — the wrapper <span> has an explicit `height`
-//      matching the font's `line-height`. Adding a child <Text> <span>
-//      inside creates a double-span where the inner element's line-height
-//      conflicts with the outer element's height, causing a ~4px vertical
-//      offset.
-//
-//   3. Interactive color overrides — CSS selectors like
-//      `.opal-content-md[data-interactive] .opal-content-md-title` set
-//      `color: var(--interactive-foreground)`. <Text> with `color="inherit"`
-//      can inherit this, but <Text> with any explicit color prop overrides
-//      it. And the wrapper <span> needs the CSS class for the selector to
-//      match — removing it breaks the cascade.
-//
-//   4. Horizontal padding — the title CSS class applies `padding: 0 0.125rem`
-//      (2px). Since <Text> uses WithoutStyles (no className/style), this
-//      padding cannot be applied to <Text> directly. A wrapper <div> was
-//      attempted but introduced additional layout conflicts.
-//
-// For these reasons, Content uses `resolveStr()` from InlineMarkdown.tsx to
-// handle `string | RichStr` rendering. `resolveStr()` returns a ReactNode
-// that slots directly into the existing single <span> — no extra wrapper,
-// no layout conflicts, pixel-exact match with main.
-// ---------------------------------------------------------------------------
-
 import "@opal/layouts/content/styles.css";
 import {
   ContentSm,
@@ -98,9 +62,6 @@ interface ContentBaseProps {
    */
   widthVariant?: ExtremaSizeVariants;
 
-  /** When `true`, the title color hooks into `Interactive.Stateful`/`Interactive.Stateless`'s `--interactive-foreground` variable. */
-  withInteractive?: boolean;
-
   /** Ref forwarded to the root `<div>` of the resolved layout. */
   ref?: React.Ref<HTMLDivElement>;
 }
@@ -130,20 +91,12 @@ type LgContentProps = ContentBaseProps & {
 type MdContentProps = ContentBaseProps & {
   sizePreset: "main-content" | "main-ui" | "secondary";
   variant?: "section";
-  /** When `true`, renders "(Optional)" beside the title in the muted font variant. */
-  optional?: boolean;
-  /** Custom muted suffix rendered beside the title. */
-  titleSuffix?: string;
+  /** Muted suffix rendered beside the title. Use `"optional"` for "(Optional)". */
+  suffix?: "optional" | (string & {});
   /** Auxiliary status icon rendered beside the title. */
   auxIcon?: "info-gray" | "info-blue" | "warning" | "error";
   /** Tag rendered beside the title. */
   tag?: TagProps;
-  /** Optional class name applied to the title element. */
-  titleClassName?: string;
-  /** Optional class name applied to the icon element. */
-  iconClassName?: string;
-  /** Content rendered below the description, indented to align with it. */
-  bottomChildren?: React.ReactNode;
 };
 
 /** ContentSm does not support descriptions or inline editing. */
@@ -174,7 +127,6 @@ function Content(props: ContentProps) {
     sizePreset = "headline",
     variant = "heading",
     widthVariant = "full",
-    withInteractive,
     ref,
     ...rest
   } = props;
@@ -187,7 +139,6 @@ function Content(props: ContentProps) {
       layout = (
         <ContentXl
           sizePreset={sizePreset}
-          withInteractive={withInteractive}
           ref={ref}
           {...(rest as Omit<ContentXlProps, "sizePreset">)}
         />
@@ -196,7 +147,6 @@ function Content(props: ContentProps) {
       layout = (
         <ContentLg
           sizePreset={sizePreset}
-          withInteractive={withInteractive}
           ref={ref}
           {...(rest as Omit<ContentLgProps, "sizePreset">)}
         />
@@ -210,7 +160,6 @@ function Content(props: ContentProps) {
     layout = (
       <ContentMd
         sizePreset={sizePreset}
-        withInteractive={withInteractive}
         ref={ref}
         {...(rest as Omit<ContentMdProps, "sizePreset">)}
       />
@@ -222,7 +171,6 @@ function Content(props: ContentProps) {
     layout = (
       <ContentSm
         sizePreset={sizePreset}
-        withInteractive={withInteractive}
         ref={ref}
         {...(rest as Omit<
           React.ComponentProps<typeof ContentSm>,

web/lib/opal/src/layouts/content/styles.css

@@ -13,7 +13,7 @@
    --------------------------------------------------------------------------- */
 
 .opal-content-xl {
-  @apply flex flex-col items-start;
+  @apply flex flex-col items-start text-text-04;
 }
 
 /* ---------------------------------------------------------------------------
@@ -63,15 +63,6 @@
   gap: 0.25rem;
 }
 
-.opal-content-xl-title {
-  @apply text-left overflow-hidden text-text-04;
-  display: -webkit-box;
-  -webkit-box-orient: vertical;
-  -webkit-line-clamp: 1;
-  padding: 0 0.125rem;
-  min-width: 0.0625rem;
-}
-
 .opal-content-xl-input-sizer {
   display: inline-grid;
   align-items: stretch;
@@ -110,7 +101,6 @@
 
 .opal-content-xl-description {
   @apply text-left w-full;
-  padding: 0 0.125rem;
 }
 
 /* ===========================================================================
@@ -127,7 +117,7 @@
    --------------------------------------------------------------------------- */
 
 .opal-content-lg {
-  @apply flex flex-row items-start;
+  @apply flex flex-row items-start text-text-04;
 }
 
 /* ---------------------------------------------------------------------------
@@ -162,15 +152,6 @@
   gap: 0.25rem;
 }
 
-.opal-content-lg-title {
-  @apply text-left overflow-hidden text-text-04;
-  display: -webkit-box;
-  -webkit-box-orient: vertical;
-  -webkit-line-clamp: 1;
-  padding: 0 0.125rem;
-  min-width: 0.0625rem;
-}
-
 .opal-content-lg-input-sizer {
   display: inline-grid;
   align-items: stretch;
@@ -209,7 +190,6 @@
 
 .opal-content-lg-description {
   @apply text-left w-full;
-  padding: 0 0.125rem;
 }
 
 /* ===========================================================================
@@ -224,7 +204,7 @@
    --------------------------------------------------------------------------- */
 
 .opal-content-md {
-  @apply flex flex-col items-start;
+  @apply flex flex-col items-start text-text-04;
 }
 
 .opal-content-md-header {
@@ -255,15 +235,6 @@
   gap: 0.25rem;
 }
 
-.opal-content-md-title {
-  @apply text-left overflow-hidden text-text-04;
-  display: -webkit-box;
-  -webkit-box-orient: vertical;
-  -webkit-line-clamp: 1;
-  padding: 0 0.125rem;
-  min-width: 0.0625rem;
-}
-
 .opal-content-md-input-sizer {
   display: inline-grid;
   align-items: stretch;
@@ -313,7 +284,6 @@
 
 .opal-content-md-description {
   @apply text-left w-full;
-  padding: 0 0.125rem;
 }
 
 /* ===========================================================================
@@ -325,7 +295,7 @@
      reverse : flex-row-reverse — title left, icon right
 
    Icon color is always text-03. Title color varies by prominence
-   (text-04 default, text-03 muted, text-02 muted-2x) via data-prominence.
+   (text-04 default, text-03 muted) via data-prominence.
    =========================================================================== */
 
 /* ---------------------------------------------------------------------------
@@ -334,7 +304,7 @@
 
 .opal-content-sm {
   /* since `ContentSm` doesn't have a description, it's possible to center-align the icon and text */
-  @apply flex items-center;
+  @apply flex items-center text-text-04;
 }
 
 .opal-content-sm[data-orientation="inline"] {
@@ -367,68 +337,51 @@
   @apply text-text-02;
 }
 
-.opal-content-sm[data-prominence="muted-2x"] .opal-content-sm-icon {
-  @apply text-text-02;
-}
-
 /* ---------------------------------------------------------------------------
    Title
    --------------------------------------------------------------------------- */
 
-.opal-content-sm-title {
-  @apply text-left overflow-hidden text-text-04 truncate;
-  display: -webkit-box;
-  -webkit-box-orient: vertical;
-  -webkit-line-clamp: 1;
-  padding: 0 0.125rem;
-  min-width: 0.0625rem;
-}
-
-.opal-content-sm[data-prominence="muted"] .opal-content-sm-title {
+.opal-content-sm[data-prominence="muted"] {
   @apply text-text-03;
 }
 
-.opal-content-sm[data-prominence="muted-2x"] .opal-content-sm-title {
-  @apply text-text-02;
-}
-
 /* ===========================================================================
-   Interactive-foreground opt-in
+   Interactive override
 
-   When a Content variant is nested inside an Interactive and
-   `withInteractive` is set, the title and icon delegate their color to the
-   `--interactive-foreground` / `--interactive-foreground-icon` CSS variables
-   controlled by the ancestor Interactive variant.
+   When a Content variant is nested inside an `.interactive` element,
+   the title inherits color from the Interactive's `--interactive-foreground`
+   and icons switch to `--interactive-foreground-icon`. This is automatic —
+   no opt-in prop is required.
    =========================================================================== */
 
-.opal-content-xl[data-interactive] .opal-content-xl-title {
-  color: var(--interactive-foreground);
+.interactive .opal-content-xl {
+  color: inherit;
 }
 
-.opal-content-xl[data-interactive] .opal-content-xl-icon {
+.interactive .opal-content-xl .opal-content-xl-icon {
   color: var(--interactive-foreground-icon);
 }
 
-.opal-content-lg[data-interactive] .opal-content-lg-title {
-  color: var(--interactive-foreground);
+.interactive .opal-content-lg {
+  color: inherit;
 }
 
-.opal-content-lg[data-interactive] .opal-content-lg-icon {
+.interactive .opal-content-lg .opal-content-lg-icon {
   color: var(--interactive-foreground-icon);
 }
 
-.opal-content-md[data-interactive] .opal-content-md-title {
-  color: var(--interactive-foreground);
+.interactive .opal-content-md {
+  color: inherit;
 }
 
-.opal-content-md[data-interactive] .opal-content-md-icon {
+.interactive .opal-content-md .opal-content-md-icon {
   color: var(--interactive-foreground-icon);
 }
 
-.opal-content-sm[data-interactive] .opal-content-sm-title {
-  color: var(--interactive-foreground);
+.interactive .opal-content-sm {
+  color: inherit;
 }
 
-.opal-content-sm[data-interactive] .opal-content-sm-icon {
+.interactive .opal-content-sm .opal-content-sm-icon {
   color: var(--interactive-foreground-icon);
 }

web/lib/opal/src/layouts/index.ts

@@ -12,6 +12,12 @@ export {
   type ContentActionProps,
 } from "@opal/layouts/content-action/components";
 
+/* CardHeaderLayout */
+export {
+  CardHeaderLayout,
+  type CardHeaderLayoutProps,
+} from "@opal/layouts/cards/header-layout/components";
+
 /* IllustrationContent */
 export {
   IllustrationContent,

web/lib/opal/src/utils.ts

@@ -6,7 +6,14 @@ export function cn(...inputs: ClassValue[]) {
   return twMerge(clsx(inputs));
 }
 
-/** Wraps a string for inline markdown parsing by `Text` and other Opal components. */
-export function markdown(content: string): RichStr {
-  return { __brand: "RichStr", raw: content };
+/**
+ * Wraps strings for inline markdown parsing by `Text` and other Opal components.
+ *
+ * Multiple arguments are joined with newlines, so each string renders on its own line:
+ * ```tsx
+ * markdown("Line one", "Line two", "Line three")
+ * ```
+ */
+export function markdown(...lines: string[]): RichStr {
+  return { __brand: "RichStr", raw: lines.join("\n") };
 }

web/src/app/admin/connectors/[connector]/pages/FieldRendering.tsx

@@ -229,7 +229,7 @@ export const RenderField: FC<RenderFieldProps> = ({
             name={field.name}
             title={label}
             description={description}
-            optional={field.optional}
+            suffix={field.optional ? "optional" : undefined}
           >
             <InputTextAreaField
               name={field.name}

web/src/app/admin/scim/ScimModal.tsx

@@ -1,5 +1,5 @@
 import { SvgDownload, SvgKey, SvgRefreshCw } from "@opal/icons";
-import { Interactive, Hoverable } from "@opal/core";
+import { Interactive } from "@opal/core";
 import { Section } from "@/layouts/general-layouts";
 import { Button } from "@opal/components";
 import { Disabled } from "@opal/core";
@@ -83,30 +83,27 @@ export default function ScimModal({
               onClose={onClose}
             />
             <Modal.Body>
-              <Hoverable.Root group="token">
-                <Interactive.Stateless
-                  onClick={() => copyToClipboard(view.rawToken)}
-                >
-                  <InputTextArea
-                    value={view.rawToken}
-                    readOnly
-                    autoResize
-                    resizable={false}
-                    rows={2}
-                    className="font-main-ui-mono break-all cursor-pointer [&_textarea]:cursor-pointer"
-                    rightSection={
-                      <div onClick={(e) => e.stopPropagation()}>
-                        <Hoverable.Item
-                          group="token"
-                          variant="opacity-on-hover"
-                        >
-                          <CopyIconButton getCopyText={() => view.rawToken} />
-                        </Hoverable.Item>
-                      </div>
-                    }
-                  />
-                </Interactive.Stateless>
-              </Hoverable.Root>
+              <Interactive.Stateless
+                group="group/token"
+                onClick={() => copyToClipboard(view.rawToken)}
+              >
+                <InputTextArea
+                  value={view.rawToken}
+                  readOnly
+                  autoResize
+                  resizable={false}
+                  rows={2}
+                  className="font-main-ui-mono break-all cursor-pointer [&_textarea]:cursor-pointer"
+                  rightSection={
+                    <div
+                      className="opacity-0 group-hover/token:opacity-100 transition-opacity"
+                      onClick={(e) => e.stopPropagation()}
+                    >
+                      <CopyIconButton getCopyText={() => view.rawToken} />
+                    </div>
+                  }
+                />
+              </Interactive.Stateless>
             </Modal.Body>
             <Modal.Footer>
               <BasicModalFooter

web/src/app/app/components/files/images/InMessageImage.tsx

@@ -4,7 +4,6 @@ import { ImageShape } from "@/app/app/services/streamingModels";
 import { FullImageModal } from "@/app/app/components/files/images/FullImageModal";
 import { buildImgUrl } from "@/app/app/components/files/images/utils";
 import { Button } from "@opal/components";
-import { Hoverable } from "@opal/core";
 import { cn } from "@/lib/utils";
 
 const DEFAULT_SHAPE: ImageShape = "square";
@@ -77,42 +76,42 @@ export const InMessageImage = memo(function InMessageImage({
         onOpenChange={(open) => setFullImageShowing(open)}
       />
 
-      <Hoverable.Root group="messageImage" widthVariant="fit">
-        <div className={cn("relative", shapeContainerClasses)}>
-          {!imageLoaded && (
-            <div className="absolute inset-0 bg-background-tint-02 animate-pulse rounded-lg" />
+      <div className={cn("relative group", shapeContainerClasses)}>
+        {!imageLoaded && (
+          <div className="absolute inset-0 bg-background-tint-02 animate-pulse rounded-lg" />
+        )}
+
+        <img
+          width={1200}
+          height={1200}
+          alt="Chat Message Image"
+          onLoad={() => {
+            loadedImages.add(fileId);
+            setImageLoaded(true);
+          }}
+          className={cn(
+            "object-contain object-left overflow-hidden rounded-lg w-full h-full transition-opacity duration-300 cursor-pointer",
+            shapeImageClasses,
+            imageLoaded ? "opacity-100" : "opacity-0"
           )}
+          onClick={() => setFullImageShowing(true)}
+          src={buildImgUrl(fileId)}
+          loading="lazy"
+        />
 
-          <img
-            width={1200}
-            height={1200}
-            alt="Chat Message Image"
-            onLoad={() => {
-              loadedImages.add(fileId);
-              setImageLoaded(true);
-            }}
-            className={cn(
-              "object-contain object-left overflow-hidden rounded-lg w-full h-full transition-opacity duration-300 cursor-pointer",
-              shapeImageClasses,
-              imageLoaded ? "opacity-100" : "opacity-0"
-            )}
-            onClick={() => setFullImageShowing(true)}
-            src={buildImgUrl(fileId)}
-            loading="lazy"
+        {/* Download button - appears on hover */}
+        <div
+          className={cn(
+            "absolute bottom-2 right-2 opacity-0 group-hover:opacity-100 z-10"
+          )}
+        >
+          <Button
+            icon={SvgDownload}
+            tooltip="Download"
+            onClick={handleDownload}
           />
-
-          {/* Download button - appears on hover */}
-          <div className="absolute bottom-2 right-2 z-10">
-            <Hoverable.Item group="messageImage" variant="opacity-on-hover">
-              <Button
-                icon={SvgDownload}
-                tooltip="Download"
-                onClick={handleDownload}
-              />
-            </Hoverable.Item>
-          </div>
         </div>
-      </Hoverable.Root>
+      </div>
     </>
   );
 });

web/src/app/app/components/projects/ProjectContextPanel.tsx

@@ -20,7 +20,6 @@ import IconButton from "@/refresh-components/buttons/IconButton";
 import ButtonRenaming from "@/refresh-components/buttons/ButtonRenaming";
 import { UserFileStatus } from "../../projects/projectsService";
 import { SvgAddLines, SvgEdit, SvgFiles, SvgFolderOpen } from "@opal/icons";
-import { Hoverable } from "@opal/core";
 
 export interface ProjectContextPanelProps {
   projectTokenCount?: number;
@@ -134,40 +133,34 @@ export default function ProjectContextPanel({
       <div className="flex flex-col gap-6 w-full max-w-[var(--app-page-main-content-width)] mx-auto p-4 pt-14 pb-6">
         <div className="flex flex-col gap-1 text-text-04">
           <SvgFolderOpen className="h-8 w-8 text-text-04" />
-          <Hoverable.Root group="projectName" widthVariant="fit">
-            <div className="flex items-center gap-2">
-              {isEditingName ? (
-                <ButtonRenaming
-                  initialName={projectName}
-                  onRename={async (newName) => {
-                    if (currentProjectId) {
-                      await renameProject(currentProjectId, newName);
-                    }
-                  }}
-                  onClose={cancelEditing}
-                  className="font-heading-h2 text-text-04"
+          <div className="group flex items-center gap-2">
+            {isEditingName ? (
+              <ButtonRenaming
+                initialName={projectName}
+                onRename={async (newName) => {
+                  if (currentProjectId) {
+                    await renameProject(currentProjectId, newName);
+                  }
+                }}
+                onClose={cancelEditing}
+                className="font-heading-h2 text-text-04"
+              />
+            ) : (
+              <>
+                <Text as="p" headingH2 className="font-heading-h2">
+                  {projectName}
+                </Text>
+                {/* TODO(@raunakab): migrate to opal Button once className/iconClassName is resolved */}
+                <IconButton
+                  icon={SvgEdit}
+                  internal
+                  onClick={startEditing}
+                  className="opacity-0 group-hover:opacity-100 focus-visible:opacity-100 transition-opacity"
+                  tooltip="Edit project name"
                 />
-              ) : (
-                <>
-                  <Text as="p" headingH2 className="font-heading-h2">
-                    {projectName}
-                  </Text>
-                  {/* TODO(@raunakab): migrate to opal Button once className/iconClassName is resolved */}
-                  <Hoverable.Item
-                    group="projectName"
-                    variant="opacity-on-hover"
-                  >
-                    <IconButton
-                      icon={SvgEdit}
-                      internal
-                      onClick={startEditing}
-                      tooltip="Edit project name"
-                    />
-                  </Hoverable.Item>
-                </>
-              )}
-            </div>
-          </Hoverable.Root>
+              </>
+            )}
+          </div>
         </div>
 
         <Separator className="py-0" />

web/src/app/app/message/HumanMessage.tsx

@@ -10,7 +10,6 @@ import useScreenSize from "@/hooks/useScreenSize";
 import CopyIconButton from "@/refresh-components/buttons/CopyIconButton";
 import { Button } from "@opal/components";
 import { SvgEdit } from "@opal/icons";
-import { Hoverable } from "@opal/core";
 import FileDisplay from "./FileDisplay";
 
 interface MessageEditingProps {
@@ -171,9 +170,9 @@ const HumanMessage = React.memo(function HumanMessage({
     return undefined;
   };
 
-  const copyEditButtonContent = useMemo(
+  const copyEditButton = useMemo(
     () => (
-      <div className="flex flex-row flex-shrink px-1">
+      <div className="flex flex-row flex-shrink px-1 opacity-0 group-hover:opacity-100 transition-opacity">
         <CopyIconButton
           getCopyText={() => content}
           prominence="tertiary"
@@ -191,94 +190,86 @@ const HumanMessage = React.memo(function HumanMessage({
     [content]
   );
 
-  const copyEditButton = (
-    <Hoverable.Item group="humanMessage" variant="opacity-on-hover">
-      {copyEditButtonContent}
-    </Hoverable.Item>
-  );
-
   return (
-    <Hoverable.Root group="humanMessage" widthVariant="full">
-      <div
-        id="onyx-human-message"
-        className="flex flex-col justify-end w-full relative"
-      >
-        <FileDisplay files={files || []} />
-        {isEditing ? (
-          <MessageEditing
-            content={content}
-            onSubmitEdit={(editedContent) => {
-              // Don't update UI for edits that can't be persisted
-              if (messageId === undefined || messageId === null) {
-                setIsEditing(false);
-                return;
-              }
-              onEdit?.(editedContent, messageId);
-              setContent(editedContent);
+    <div
+      id="onyx-human-message"
+      className="group flex flex-col justify-end w-full relative"
+    >
+      <FileDisplay files={files || []} />
+      {isEditing ? (
+        <MessageEditing
+          content={content}
+          onSubmitEdit={(editedContent) => {
+            // Don't update UI for edits that can't be persisted
+            if (messageId === undefined || messageId === null) {
               setIsEditing(false);
-            }}
-            onCancelEdit={() => setIsEditing(false)}
-          />
-        ) : (
-          <div className="flex justify-end">
-            {onEdit && !isMobile && copyEditButton}
-            <div className="md:max-w-[37.5rem]">
-              <div
-                className={
-                  "max-w-[30rem] md:max-w-[37.5rem] whitespace-break-spaces break-anywhere rounded-t-16 rounded-bl-16 bg-background-tint-02 py-2 px-3"
+              return;
+            }
+            onEdit?.(editedContent, messageId);
+            setContent(editedContent);
+            setIsEditing(false);
+          }}
+          onCancelEdit={() => setIsEditing(false)}
+        />
+      ) : (
+        <div className="flex justify-end">
+          {onEdit && !isMobile && copyEditButton}
+          <div className="md:max-w-[37.5rem]">
+            <div
+              className={
+                "max-w-[30rem] md:max-w-[37.5rem] whitespace-break-spaces break-anywhere rounded-t-16 rounded-bl-16 bg-background-tint-02 py-2 px-3"
+              }
+              onCopy={(e) => {
+                const selection = window.getSelection();
+                if (selection) {
+                  e.preventDefault();
+                  const text = selection
+                    .toString()
+                    .replace(/\n{2,}/g, "\n")
+                    .trim();
+                  e.clipboardData.setData("text/plain", text);
                 }
-                onCopy={(e) => {
-                  const selection = window.getSelection();
-                  if (selection) {
-                    e.preventDefault();
-                    const text = selection
-                      .toString()
-                      .replace(/\n{2,}/g, "\n")
-                      .trim();
-                    e.clipboardData.setData("text/plain", text);
-                  }
-                }}
+              }}
+            >
+              <Text
+                as="p"
+                className="inline-block align-middle"
+                mainContentBody
               >
-                <Text
-                  as="p"
-                  className="inline-block align-middle"
-                  mainContentBody
-                >
-                  {content}
-                </Text>
-              </div>
+                {content}
+              </Text>
             </div>
           </div>
-        )}
-        <div className="flex justify-end pt-1">
-          {!isEditing && onEdit && isMobile && copyEditButton}
-          {currentMessageInd !== undefined &&
-            onMessageSelection &&
-            otherMessagesCanSwitchTo &&
-            otherMessagesCanSwitchTo.length > 1 && (
-              <MessageSwitcher
-                disableForStreaming={disableSwitchingForStreaming}
-                currentPage={currentMessageInd + 1}
-                totalPages={otherMessagesCanSwitchTo.length}
-                handlePrevious={() => {
-                  stopGenerating();
-                  const prevMessage = getPreviousMessage();
-                  if (prevMessage !== undefined) {
-                    onMessageSelection(prevMessage);
-                  }
-                }}
-                handleNext={() => {
-                  stopGenerating();
-                  const nextMessage = getNextMessage();
-                  if (nextMessage !== undefined) {
-                    onMessageSelection(nextMessage);
-                  }
-                }}
-              />
-            )}
         </div>
+      )}
+      <div className="flex justify-end pt-1">
+        {!isEditing && onEdit && isMobile && copyEditButton}
+        {currentMessageInd !== undefined &&
+          onMessageSelection &&
+          otherMessagesCanSwitchTo &&
+          otherMessagesCanSwitchTo.length > 1 && (
+            <MessageSwitcher
+              disableForStreaming={disableSwitchingForStreaming}
+              currentPage={currentMessageInd + 1}
+              totalPages={otherMessagesCanSwitchTo.length}
+              handlePrevious={() => {
+                stopGenerating();
+                const prevMessage = getPreviousMessage();
+                if (prevMessage !== undefined) {
+                  onMessageSelection(prevMessage);
+                }
+              }}
+              handleNext={() => {
+                stopGenerating();
+                const nextMessage = getNextMessage();
+                if (nextMessage !== undefined) {
+                  onMessageSelection(nextMessage);
+                }
+              }}
+            />
+          )}
       </div>
-    </Hoverable.Root>
+    </div>
   );
 }, arePropsEqual);
 

web/src/app/app/services/lib.tsx

@@ -182,7 +182,8 @@ export async function* sendMessage({
   });
 
   if (!response.ok) {
-    throw new Error(`HTTP error! status: ${response.status}`);
+    const data = await response.json().catch(() => ({}));
+    throw new Error(data.detail ?? `HTTP error! status: ${response.status}`);
   }
 
   yield* handleSSEStream<PacketType>(response, signal);

web/src/hooks/useChatController.ts

@@ -901,6 +901,11 @@ export default function useChatController({
             });
           }
         }
+        // Surface FIFO errors (e.g. 429 before any packets arrive) so the
+        // catch block replaces the thinking placeholder with an error message.
+        if (stack.error) {
+          throw new Error(stack.error);
+        }
       } catch (e: any) {
         console.log("Error:", e);
         const errorMsg = e.message;

web/src/layouts/input-layouts.tsx

@@ -15,9 +15,8 @@ interface OrientationLayoutProps {
   nonInteractive?: boolean;
   children?: React.ReactNode;
   title: string | RichStr;
-  titleSuffix?: string;
   description?: string | RichStr;
-  optional?: boolean;
+  suffix?: "optional" | (string & {});
   sizePreset?: "main-content" | "main-ui";
 }
 
@@ -53,18 +52,16 @@ function VerticalInputLayout({
   children,
   subDescription,
   title,
-  titleSuffix,
   description,
-  optional,
+  suffix,
   sizePreset = "main-content",
 }: VerticalLayoutProps) {
   const content = (
     <Section gap={0.25} alignItems="start">
       <Content
         title={title}
-        titleSuffix={titleSuffix}
         description={description}
-        optional={optional}
+        suffix={suffix}
         sizePreset={sizePreset}
         variant="section"
       />
@@ -130,9 +127,8 @@ function HorizontalInputLayout({
   children,
   center,
   title,
-  titleSuffix,
   description,
-  optional,
+  suffix,
   sizePreset = "main-content",
 }: HorizontalLayoutProps) {
   const content = (
@@ -145,9 +141,8 @@ function HorizontalInputLayout({
         <div className="flex flex-col flex-1 min-w-0 self-stretch">
           <Content
             title={title}
-            titleSuffix={titleSuffix}
             description={description}
-            optional={optional}
+            suffix={suffix}
             sizePreset={sizePreset}
             variant="section"
             widthVariant="full"

web/src/refresh-components/buttons/SidebarTab.tsx

@@ -57,7 +57,7 @@ export default function SidebarTab({
   const content = (
     <div className="relative">
       <Interactive.Stateful
-        variant="sidebar"
+        variant={lowlight ? "sidebar-light" : "sidebar-heavy"}
         state={selected ? "selected" : "empty"}
         onClick={onClick}
         type="button"
@@ -90,9 +90,6 @@ export default function SidebarTab({
               title={folded ? "" : children}
               sizePreset="main-ui"
               variant="body"
-              prominence={
-                lowlight ? "muted-2x" : selected ? "default" : "muted"
-              }
               widthVariant="full"
               paddingVariant="fit"
               rightChildren={truncationSpacer}

web/src/refresh-components/inputs/InputImage.tsx

@@ -1,8 +1,8 @@
 "use client";
 
+import React from "react";
 import { cn, noProp } from "@/lib/utils";
 import { SvgPlus, SvgX } from "@opal/icons";
-import { Hoverable } from "@opal/core";
 import IconButton from "@/refresh-components/buttons/IconButton";
 import SimpleTooltip from "@/refresh-components/SimpleTooltip";
 import Text from "@/refresh-components/texts/Text";
@@ -173,106 +173,103 @@ export default function InputImage({
   const dropzoneProps = onDrop ? getRootProps() : {};
 
   return (
-    <Hoverable.Root group="inputImage" widthVariant="fit">
-      <div
-        className={cn("relative", className)}
-        style={{ width: size, height: size }}
-        {...dropzoneProps}
+    <div
+      className={cn("relative group", className)}
+      style={{ width: size, height: size }}
+      {...dropzoneProps}
+    >
+      {/* Hidden input for file selection */}
+      {onDrop && <input {...getInputProps()} />}
+
+      {/* Main container */}
+      <button
+        type="button"
+        onClick={handleClick}
+        disabled={disabled}
+        className={cn(
+          "relative w-full h-full rounded-full overflow-hidden",
+          "border flex items-center justify-center",
+          "transition-all duration-150",
+          containerClass
+        )}
+        aria-label={
+          isInteractive ? (hasImage ? "Edit image" : "Upload image") : undefined
+        }
       >
-        {/* Hidden input for file selection */}
-        {onDrop && <input {...getInputProps()} />}
+        {/* Content */}
+        {hasImage ? (
+          <img
+            src={src}
+            alt={alt}
+            className="absolute inset-0 w-full h-full object-cover pointer-events-none"
+          />
+        ) : (
+          <SvgPlus
+            className={cn("w-6 h-6", placeholderClass, "pointer-events-none")}
+          />
+        )}
 
-        {/* Main container */}
-        <button
-          type="button"
-          onClick={handleClick}
-          disabled={disabled}
-          className={cn(
-            "group relative w-full h-full rounded-full overflow-hidden",
-            "border flex items-center justify-center",
-            "transition-all duration-150",
-            containerClass
-          )}
-          aria-label={
-            isInteractive
-              ? hasImage
-                ? "Edit image"
-                : "Upload image"
-              : undefined
-          }
-        >
-          {/* Content */}
-          {hasImage ? (
-            <img
-              src={src}
-              alt={alt}
-              className="absolute inset-0 w-full h-full object-cover pointer-events-none"
-            />
-          ) : (
-            <SvgPlus
-              className={cn("w-6 h-6", placeholderClass, "pointer-events-none")}
-            />
-          )}
+        {/* Drag overlay indicator */}
+        {isDragActive && (
+          <div className="absolute inset-0 bg-action-link-05/10 flex items-center justify-center rounded-full pointer-events-none">
+            <SvgPlus className="w-8 h-8 stroke-action-link-05" />
+          </div>
+        )}
 
-          {/* Drag overlay indicator */}
-          {isDragActive && (
-            <div className="absolute inset-0 bg-action-link-05/10 flex items-center justify-center rounded-full pointer-events-none">
-              <SvgPlus className="w-8 h-8 stroke-action-link-05" />
-            </div>
-          )}
-
-          {/* Edit overlay - shows on hover/focus when image is uploaded */}
-          {showEditOverlay && isInteractive && hasImage && !isDragActive && (
-            <div className="absolute bottom-0 left-0 right-0 pointer-events-none">
-              <Hoverable.Item group="inputImage" variant="opacity-on-hover">
+        {/* Edit overlay - shows on hover/focus when image is uploaded */}
+        {showEditOverlay && isInteractive && hasImage && !isDragActive && (
+          <div
+            className={cn(
+              "absolute bottom-0 left-0 right-0",
+              "flex items-center justify-center",
+              "pb-2.5 pt-1.5",
+              "opacity-0 group-hover:opacity-100 group-focus-within:opacity-100",
+              "transition-opacity duration-150",
+              "backdrop-blur-sm bg-mask-01",
+              "pointer-events-none"
+            )}
+          >
+            <div className="pointer-events-auto">
+              <SimpleTooltip tooltip="Edit" side="top">
                 <div
                   className={cn(
                     "flex items-center justify-center",
-                    "pb-2.5 pt-1.5",
-                    "backdrop-blur-sm bg-mask-01",
-                    "pointer-events-none"
+                    "px-1 py-0.5 rounded-08"
                   )}
                 >
-                  <div className="pointer-events-auto">
-                    <SimpleTooltip tooltip="Edit" side="top">
-                      <div
-                        className={cn(
-                          "flex items-center justify-center",
-                          "px-1 py-0.5 rounded-08"
-                        )}
-                      >
-                        <Text
-                          className="text-text-03 font-secondary-action"
-                          style={{ fontSize: "12px", lineHeight: "16px" }}
-                        >
-                          Edit
-                        </Text>
-                      </div>
-                    </SimpleTooltip>
-                  </div>
+                  <Text
+                    className="text-text-03 font-secondary-action"
+                    style={{ fontSize: "12px", lineHeight: "16px" }}
+                  >
+                    Edit
+                  </Text>
                 </div>
-              </Hoverable.Item>
+              </SimpleTooltip>
             </div>
-          )}
-        </button>
-
-        {/* Remove button - top left corner (only when image is uploaded) */}
-        {isInteractive && hasImage && onRemove && (
-          <div className="absolute top-1 left-1">
-            <Hoverable.Item group="inputImage" variant="opacity-on-hover">
-              {/* TODO(@raunakab): migrate to opal Button once className/iconClassName is resolved */}
-              <IconButton
-                icon={SvgX}
-                onClick={noProp(onRemove)}
-                type="button"
-                primary
-                className="!w-5 !h-5 !p-0.5 !rounded-04"
-                aria-label="Remove image"
-              />
-            </Hoverable.Item>
           </div>
         )}
-      </div>
-    </Hoverable.Root>
+      </button>
+
+      {/* Remove button - top left corner (only when image is uploaded) */}
+      {isInteractive && hasImage && onRemove && (
+        <div
+          className={cn(
+            "absolute top-1 left-1",
+            "opacity-0 group-hover:opacity-100 group-focus-within:opacity-100",
+            "transition-opacity duration-150"
+          )}
+        >
+          {/* TODO(@raunakab): migrate to opal Button once className/iconClassName is resolved */}
+          <IconButton
+            icon={SvgX}
+            onClick={noProp(onRemove)}
+            type="button"
+            primary
+            className="!w-5 !h-5 !p-0.5 !rounded-04"
+            aria-label="Remove image"
+          />
+        </div>
+      )}
+    </div>
   );
 }

web/src/refresh-components/tiles/FileTile.tsx

@@ -3,7 +3,6 @@ import type { FunctionComponent } from "react";
 import { cn, noProp } from "@/lib/utils";
 import { SvgMaximize2, SvgTextLines, SvgX } from "@opal/icons";
 import type { IconProps } from "@opal/types";
-import { Hoverable } from "@opal/core";
 import IconButton from "../buttons/IconButton";
 import Text from "../texts/Text";
 import Truncated from "../texts/Truncated";
@@ -33,32 +32,25 @@ interface RemoveButtonProps {
 
 function RemoveButton({ onRemove }: RemoveButtonProps) {
   return (
-    <div
+    <button
+      type="button"
+      onClick={(e) => {
+        e.stopPropagation();
+        onRemove();
+      }}
+      title="Remove"
+      aria-label="Remove"
       className={cn(
-        "absolute -left-1 -top-1 z-10",
-        "pointer-events-none focus-within:pointer-events-auto"
+        "absolute -left-1 -top-1 z-10 h-4 w-4",
+        "flex items-center justify-center",
+        "rounded-full bg-theme-primary-05 text-text-inverted-05",
+        "opacity-0 group-hover/Tile:opacity-100 focus:opacity-100",
+        "pointer-events-none group-hover/Tile:pointer-events-auto focus:pointer-events-auto",
+        "transition-opacity duration-150"
       )}
     >
-      <Hoverable.Item group="fileTile" variant="opacity-on-hover">
-        <button
-          type="button"
-          onClick={(e) => {
-            e.stopPropagation();
-            onRemove();
-          }}
-          title="Remove"
-          aria-label="Remove"
-          className={cn(
-            "h-4 w-4",
-            "flex items-center justify-center",
-            "rounded-full bg-theme-primary-05 text-text-inverted-05",
-            "pointer-events-auto"
-          )}
-        >
-          <SvgX size={10} />
-        </button>
-      </Hoverable.Item>
-    </div>
+      <SvgX size={10} />
+    </button>
   );
 }
 
@@ -78,7 +70,7 @@ export default function FileTile({
   const isMuted = state === "processing" || state === "disabled";
 
   return (
-    <Hoverable.Root group="fileTile" widthVariant="fit">
+    <div className="group/Tile">
       <div
         onClick={onOpen && state !== "disabled" ? () => onOpen() : undefined}
         className={cn(
@@ -91,8 +83,8 @@ export default function FileTile({
             ? "bg-background-neutral-02 border-border-01"
             : "bg-background-tint-00 border-border-01",
           // Hover overrides (disabled gets none)
-          state !== "disabled" && "hover:border-border-02",
-          state === "default" && "hover:bg-background-tint-02",
+          state !== "disabled" && "group-hover/Tile:border-border-02",
+          state === "default" && "group-hover/Tile:bg-background-tint-02",
           // Clickable cursor when onOpen is provided and not disabled
           onOpen && state !== "disabled" && "cursor-pointer"
         )}
@@ -122,7 +114,7 @@ export default function FileTile({
                     text02
                     className={cn(
                       "truncate",
-                      state === "processing" && "hover:text-text-03"
+                      state === "processing" && "group-hover/Tile:text-text-03"
                     )}
                   >
                     {title}
@@ -134,7 +126,7 @@ export default function FileTile({
                     text02
                     className={cn(
                       "line-clamp-2",
-                      state === "processing" && "hover:text-text-03"
+                      state === "processing" && "group-hover/Tile:text-text-03"
                     )}
                   >
                     {description}
@@ -167,6 +159,6 @@ export default function FileTile({
           </div>
         )}
       </div>
-    </Hoverable.Root>
+    </div>
   );
 }

web/src/refresh-pages/AgentEditorPage.tsx

@@ -6,7 +6,7 @@ import * as SettingsLayouts from "@/layouts/settings-layouts";
 import * as GeneralLayouts from "@/layouts/general-layouts";
 import Button from "@/refresh-components/buttons/Button";
 import { Button as OpalButton } from "@opal/components";
-import { Disabled, Hoverable } from "@opal/core";
+import { Disabled } from "@opal/core";
 import { FullPersona } from "@/app/admin/agents/interfaces";
 import { buildImgUrl } from "@/app/app/components/files/images/utils";
 import { Formik, Form, FieldArray } from "formik";
@@ -212,25 +212,22 @@ function AgentIconEditor({ existingAgent }: AgentIconEditorProps) {
 
       <Popover open={popoverOpen} onOpenChange={setPopoverOpen}>
         <Popover.Trigger asChild>
-          <Hoverable.Root group="inputAvatar" widthVariant="fit">
-            <InputAvatar className="relative flex flex-col items-center justify-center h-[7.5rem] w-[7.5rem]">
-              {/* We take the `InputAvatar`'s height/width (in REM) and multiply it by 16 (the REM -> px conversion factor). */}
-              <CustomAgentAvatar
-                size={imageSrc ? 7.5 * 16 : 40}
-                src={imageSrc}
-                iconName={values.icon_name ?? undefined}
-                name={values.name}
-              />
-              {/* TODO(@raunakab): migrate to opal Button once className/iconClassName is resolved */}
-              <div className="absolute bottom-0 left-1/2 -translate-x-1/2 mb-2">
-                <Hoverable.Item group="inputAvatar" variant="opacity-on-hover">
-                  <Button className="h-[1.75rem]" secondary>
-                    Edit
-                  </Button>
-                </Hoverable.Item>
-              </div>
-            </InputAvatar>
-          </Hoverable.Root>
+          <InputAvatar className="group/InputAvatar relative flex flex-col items-center justify-center h-[7.5rem] w-[7.5rem]">
+            {/* We take the `InputAvatar`'s height/width (in REM) and multiply it by 16 (the REM -> px conversion factor). */}
+            <CustomAgentAvatar
+              size={imageSrc ? 7.5 * 16 : 40}
+              src={imageSrc}
+              iconName={values.icon_name ?? undefined}
+              name={values.name}
+            />
+            {/* TODO(@raunakab): migrate to opal Button once className/iconClassName is resolved */}
+            <Button
+              className="absolute bottom-0 left-1/2 -translate-x-1/2 h-[1.75rem] mb-2 invisible group-hover/InputAvatar:visible"
+              secondary
+            >
+              Edit
+            </Button>
+          </InputAvatar>
         </Popover.Trigger>
         <Popover.Content>
           <PopoverMenu>
@@ -1271,7 +1268,7 @@ export default function AgentEditorPage({
                           <InputLayouts.Vertical
                             name="description"
                             title="Description"
-                            optional
+                            suffix="optional"
                           >
                             <InputTextAreaField
                               name="description"
@@ -1296,7 +1293,7 @@ export default function AgentEditorPage({
                         <InputLayouts.Vertical
                           name="instructions"
                           title="Instructions"
-                          optional
+                          suffix="optional"
                           description="Add instructions to tailor the response for this agent."
                         >
                           <InputTextAreaField
@@ -1309,7 +1306,7 @@ export default function AgentEditorPage({
                           name="starter_messages"
                           title="Conversation Starters"
                           description="Example messages that help users understand what this agent can do and how to interact with it effectively."
-                          optional
+                          suffix="optional"
                         >
                           <StarterMessages />
                         </InputLayouts.Vertical>
@@ -1549,7 +1546,7 @@ export default function AgentEditorPage({
                               <InputLayouts.Horizontal
                                 name="knowledge_cutoff_date"
                                 title="Knowledge Cutoff Date"
-                                optional
+                                suffix="optional"
                                 description="Documents with a last-updated date prior to this will be ignored."
                               >
                                 <InputDatePickerField
@@ -1560,7 +1557,7 @@ export default function AgentEditorPage({
                               <InputLayouts.Horizontal
                                 name="replace_base_system_prompt"
                                 title="Overwrite System Prompt"
-                                titleSuffix="(Not Recommended)"
+                                suffix="(Not Recommended)"
                                 description='Remove the base system prompt which includes useful instructions (e.g. "You can use Markdown tables"). This may affect response quality.'
                               >
                                 <SwitchField name="replace_base_system_prompt" />
@@ -1571,7 +1568,7 @@ export default function AgentEditorPage({
                               <InputLayouts.Vertical
                                 name="reminders"
                                 title="Reminders"
-                                optional
+                                suffix="optional"
                               >
                                 <InputTextAreaField
                                   name="reminders"

web/src/refresh-pages/admin/ChatPreferencesPage.tsx

@@ -54,7 +54,7 @@ import useOpenApiTools from "@/hooks/useOpenApiTools";
 import * as ExpandableCard from "@/layouts/expandable-card-layouts";
 import * as ActionsLayouts from "@/layouts/actions-layouts";
 import { getActionIcon } from "@/lib/tools/mcpUtils";
-import { Disabled, Hoverable } from "@opal/core";
+import { Disabled } from "@opal/core";
 import IconButton from "@/refresh-components/buttons/IconButton";
 import InputTypeIn from "@/refresh-components/inputs/InputTypeIn";
 import useFilter from "@/hooks/useFilter";
@@ -281,7 +281,7 @@ function NumericLimitField({
   };
 
   return (
-    <Hoverable.Root group="numericLimit" widthVariant="full">
+    <div className="group w-full">
       <InputTypeInField
         name={name}
         inputMode="numeric"
@@ -291,7 +291,7 @@ function NumericLimitField({
         variant={isOverMax ? "error" : undefined}
         rightSection={
           (value || "") !== defaultValue ? (
-            <Hoverable.Item group="numericLimit" variant="opacity-on-hover">
+            <div className="opacity-0 group-hover:opacity-100 group-focus-within:opacity-100 transition-opacity">
               <IconButton
                 icon={SvgRefreshCw}
                 tooltip="Restore default"
@@ -299,12 +299,12 @@ function NumericLimitField({
                 type="button"
                 onClick={handleRestore}
               />
-            </Hoverable.Item>
+            </div>
           ) : undefined
         }
         onBlur={handleBlur}
       />
-    </Hoverable.Root>
+    </div>
   );
 }
 

web/src/refresh-pages/admin/HooksPage/ConnectedHookCard.tsx

@@ -5,7 +5,8 @@ import { toast } from "@/hooks/useToast";
 import { Button } from "@opal/components";
 import { Disabled } from "@opal/core";
 import { cn } from "@/lib/utils";
-import { ContentAction } from "@opal/layouts";
+import { markdown } from "@opal/utils";
+import { Content } from "@opal/layouts";
 import Card from "@/refresh-components/cards/Card";
 import Text from "@/refresh-components/texts/Text";
 import { Section } from "@/layouts/general-layouts";
@@ -310,110 +311,109 @@ export default function ConnectedHookCard({
           !hook.is_active && "!bg-background-neutral-02"
         )}
       >
-        <ContentAction
-          sizePreset="main-ui"
-          variant="section"
-          paddingVariant="sm"
-          icon={HookIcon}
-          title={hook.name}
-          titleClassName={!hook.is_active ? "line-through" : undefined}
-          iconClassName="text-text-04"
-          description={`Hook Point: ${spec?.display_name ?? hook.hook_point}`}
-          bottomChildren={
-            spec?.docs_url ? (
+        <div className="w-full flex flex-row">
+          <div className="flex-1 p-2">
+            <Content
+              sizePreset="main-ui"
+              variant="section"
+              icon={HookIcon}
+              title={!hook.is_active ? markdown(`~~${hook.name}~~`) : hook.name}
+              description={`Hook Point: ${
+                spec?.display_name ?? hook.hook_point
+              }`}
+            />
+
+            {spec?.docs_url && (
               <a
                 href={spec.docs_url}
                 target="_blank"
                 rel="noopener noreferrer"
-                className="flex items-center gap-1 w-fit font-secondary-body text-text-03"
+                className="pl-6 flex items-center gap-1"
               >
-                <span className="underline">Documentation</span>
+                <span className="underline font-secondary-body text-text-03">
+                  Documentation
+                </span>
                 <SvgExternalLink size={12} className="shrink-0" />
               </a>
-            ) : undefined
-          }
-          rightChildren={
-            <Section
-              flexDirection="column"
-              alignItems="end"
-              width="fit"
-              height="fit"
-              gap={0}
-            >
-              <div className="flex items-center gap-1 p-2">
+            )}
+          </div>
+
+          <Section
+            flexDirection="column"
+            alignItems="end"
+            width="fit"
+            height="fit"
+            gap={0}
+          >
+            <div className="flex items-center gap-1 p-2">
+              {hook.is_active ? (
+                <>
+                  <Text mainUiAction text03>
+                    Connected
+                  </Text>
+                  <SvgCheckCircle
+                    size={16}
+                    className="text-status-success-05"
+                  />
+                </>
+              ) : (
+                <div
+                  className={cn(
+                    "flex items-center gap-1",
+                    isBusy ? "opacity-50 pointer-events-none" : "cursor-pointer"
+                  )}
+                  onClick={handleActivate}
+                >
+                  <Text mainUiAction text03>
+                    Reconnect
+                  </Text>
+                  <SvgPlug size={16} className="text-text-03 shrink-0" />
+                </div>
+              )}
+            </div>
+            <Disabled disabled={isBusy}>
+              <div className="flex items-center gap-0.5 pl-1 pr-1 pb-1">
                 {hook.is_active ? (
                   <>
-                    <Text mainUiAction text03>
-                      Connected
-                    </Text>
-                    <SvgCheckCircle
-                      size={16}
-                      className="text-status-success-05"
-                    />
-                  </>
-                ) : (
-                  <div
-                    className={cn(
-                      "flex items-center gap-1",
-                      isBusy
-                        ? "opacity-50 pointer-events-none"
-                        : "cursor-pointer"
-                    )}
-                    onClick={handleActivate}
-                  >
-                    <Text mainUiAction text03>
-                      Reconnect
-                    </Text>
-                    <SvgPlug size={16} className="text-text-03 shrink-0" />
-                  </div>
-                )}
-              </div>
-              <Disabled disabled={isBusy}>
-                {/* Plain div instead of Section: Section applies style={{ padding }} inline which
-                    overrides Tailwind padding classes, making per-side padding (pl/pr/pb) ineffective. */}
-                <div className="flex items-center gap-0.5 pl-1 pr-1 pb-1">
-                  {hook.is_active ? (
-                    <>
-                      <Button
-                        prominence="tertiary"
-                        size="sm"
-                        icon={SvgUnplug}
-                        onClick={() => setDisconnectConfirmOpen(true)}
-                        tooltip="Disconnect Hook"
-                        aria-label="Deactivate hook"
-                      />
-                      <Button
-                        prominence="tertiary"
-                        size="sm"
-                        icon={SvgRefreshCw}
-                        onClick={handleValidate}
-                        tooltip="Test Connection"
-                        aria-label="Re-validate hook"
-                      />
-                    </>
-                  ) : (
                     <Button
                       prominence="tertiary"
                       size="sm"
-                      icon={SvgTrash}
-                      onClick={() => setDeleteConfirmOpen(true)}
-                      tooltip="Delete"
-                      aria-label="Delete hook"
+                      icon={SvgUnplug}
+                      onClick={() => setDisconnectConfirmOpen(true)}
+                      tooltip="Disconnect Hook"
+                      aria-label="Deactivate hook"
                     />
-                  )}
+                    <Button
+                      prominence="tertiary"
+                      size="sm"
+                      icon={SvgRefreshCw}
+                      onClick={handleValidate}
+                      tooltip="Test Connection"
+                      aria-label="Re-validate hook"
+                    />
+                  </>
+                ) : (
                   <Button
                     prominence="tertiary"
                     size="sm"
-                    icon={SvgSettings}
-                    onClick={onEdit}
-                    tooltip="Manage"
-                    aria-label="Configure hook"
+                    icon={SvgTrash}
+                    onClick={() => setDeleteConfirmOpen(true)}
+                    tooltip="Delete"
+                    aria-label="Delete hook"
                   />
-                </div>
-              </Disabled>
-            </Section>
-          }
-        />
+                )}
+                <Button
+                  prominence="tertiary"
+                  size="sm"
+                  icon={SvgSettings}
+                  onClick={onEdit}
+                  tooltip="Manage"
+                  aria-label="Configure hook"
+                />
+              </div>
+            </Disabled>
+          </Section>
+        </div>
       </Card>
     </>
   );

web/src/refresh-pages/admin/HooksPage/HooksContent.tsx

@@ -5,7 +5,7 @@ import { useHookSpecs } from "@/hooks/useHookSpecs";
 import { useHooks } from "@/hooks/useHooks";
 import SimpleLoader from "@/refresh-components/loaders/SimpleLoader";
 import { Button } from "@opal/components";
-import { ContentAction } from "@opal/layouts";
+import { Content } from "@opal/layouts";
 import InputSearch from "@/refresh-components/inputs/InputSearch";
 import Card from "@/refresh-components/cards/Card";
 import Text from "@/refresh-components/texts/Text";
@@ -17,6 +17,7 @@ import type {
   HookPointMeta,
   HookResponse,
 } from "@/refresh-pages/admin/HooksPage/interfaces";
+import { markdown } from "@opal/utils";
 
 // ---------------------------------------------------------------------------
 // Main component
@@ -145,37 +146,39 @@ export default function HooksContent() {
                     gap={0}
                     className="hover:border-border-02"
                   >
-                    <ContentAction
-                      sizePreset="main-ui"
-                      variant="section"
-                      paddingVariant="sm"
-                      icon={UnconnectedIcon}
-                      title={spec.display_name}
-                      iconClassName="text-text-04"
-                      description={spec.description}
-                      bottomChildren={
-                        spec.docs_url ? (
+                    <div className="w-full flex flex-row">
+                      <div className="flex-1 p-2">
+                        <Content
+                          sizePreset="main-ui"
+                          variant="section"
+                          icon={UnconnectedIcon}
+                          title={spec.display_name}
+                          description={spec.description}
+                        />
+
+                        {spec.docs_url && (
                           <a
                             href={spec.docs_url}
                             target="_blank"
                             rel="noopener noreferrer"
-                            className="flex items-center gap-1 w-fit font-secondary-body text-text-03"
+                            className="pl-6 flex items-center gap-1"
                           >
-                            <span className="underline">Documentation</span>
+                            <span className="underline font-secondary-body text-text-03">
+                              Documentation
+                            </span>
                             <SvgExternalLink size={12} className="shrink-0" />
                           </a>
-                        ) : undefined
-                      }
-                      rightChildren={
-                        <Button
-                          prominence="tertiary"
-                          rightIcon={SvgArrowExchange}
-                          onClick={() => setConnectSpec(spec)}
-                        >
-                          Connect
-                        </Button>
-                      }
-                    />
+                        )}
+                      </div>
+
+                      <Button
+                        prominence="tertiary"
+                        rightIcon={SvgArrowExchange}
+                        onClick={() => setConnectSpec(spec)}
+                      >
+                        Connect
+                      </Button>
+                    </div>
                   </Card>
                 );
               })}

web/src/refresh-pages/admin/LLMConfigurationPage.tsx

@@ -216,7 +216,7 @@ function ExistingProviderCard({
             icon={getProviderIcon(provider.provider)}
             title={provider.name}
             description={getProviderDisplayName(provider.provider)}
-            sizePreset="main-content"
+            sizePreset="main-ui"
             variant="section"
             tag={isDefault ? { title: "Default", color: "blue" } : undefined}
             rightChildren={
@@ -280,7 +280,7 @@ function NewProviderCard({
         icon={getProviderIcon(provider.name)}
         title={getProviderProductName(provider.name)}
         description={getProviderDisplayName(provider.name)}
-        sizePreset="main-content"
+        sizePreset="main-ui"
         variant="section"
         rightChildren={
           <Button
@@ -316,7 +316,7 @@ function NewCustomProviderCard({
         icon={getProviderIcon("custom")}
         title={getProviderProductName("custom")}
         description={getProviderDisplayName("custom")}
-        sizePreset="main-content"
+        sizePreset="main-ui"
         variant="section"
         rightChildren={
           <Button

web/src/refresh-pages/admin/UsersPage/UsersSummary.tsx

@@ -1,7 +1,6 @@
 import { SvgArrowUpRight, SvgFilterPlus, SvgUserSync } from "@opal/icons";
 import { ContentAction } from "@opal/layouts";
 import { Button } from "@opal/components";
-import { Hoverable } from "@opal/core";
 import { Section } from "@/layouts/general-layouts";
 import Card from "@/refresh-components/cards/Card";
 import IconButton from "@/refresh-components/buttons/IconButton";
@@ -23,38 +22,33 @@ function StatCell({ value, label, onFilter }: StatCellProps) {
   const display = value === null ? "\u2014" : value.toLocaleString();
 
   return (
-    <Hoverable.Root group="stat" widthVariant="full">
-      <div
-        className={`relative flex flex-col items-start gap-0.5 w-full p-2 rounded-08 transition-colors ${
-          onFilter ? "cursor-pointer hover:bg-background-tint-02" : ""
-        }`}
-        onClick={onFilter}
-      >
-        <Text as="span" mainUiAction text04>
-          {display}
-        </Text>
-        <Text as="span" secondaryBody text03>
-          {label}
-        </Text>
-        {onFilter && (
-          <div className="absolute right-1 top-1">
-            <Hoverable.Item group="stat" variant="opacity-on-hover">
-              <IconButton
-                tertiary
-                icon={SvgFilterPlus}
-                tooltip="Add Filter"
-                toolTipPosition="left"
-                tooltipSize="sm"
-                onClick={(e) => {
-                  e.stopPropagation();
-                  onFilter();
-                }}
-              />
-            </Hoverable.Item>
-          </div>
-        )}
-      </div>
-    </Hoverable.Root>
+    <div
+      className={`group/stat relative flex flex-col items-start gap-0.5 w-full p-2 rounded-08 transition-colors ${
+        onFilter ? "cursor-pointer hover:bg-background-tint-02" : ""
+      }`}
+      onClick={onFilter}
+    >
+      <Text as="span" mainUiAction text04>
+        {display}
+      </Text>
+      <Text as="span" secondaryBody text03>
+        {label}
+      </Text>
+      {onFilter && (
+        <IconButton
+          tertiary
+          icon={SvgFilterPlus}
+          tooltip="Add Filter"
+          toolTipPosition="left"
+          tooltipSize="sm"
+          className="absolute right-1 top-1 opacity-0 group-hover/stat:opacity-100 transition-opacity"
+          onClick={(e) => {
+            e.stopPropagation();
+            onFilter();
+          }}
+        />
+      )}
+    </div>
   );
 }
 

web/src/sections/actions/modals/AddMCPServerModal.tsx

@@ -158,7 +158,7 @@ export default function AddMCPServerModal({
                 <InputLayouts.Vertical
                   name="description"
                   title="Description"
-                  optional
+                  suffix="optional"
                 >
                   <InputTextAreaField
                     name="description"

web/src/sections/actions/modals/AddOpenAPIActionModal.tsx

@@ -11,7 +11,7 @@ import Separator from "@/refresh-components/Separator";
 import { useCallback, useEffect, useMemo, useState } from "react";
 import CopyIconButton from "@/refresh-components/buttons/CopyIconButton";
 import { Button } from "@opal/components";
-import { Disabled, Hoverable } from "@opal/core";
+import { Disabled } from "@opal/core";
 import { MethodSpec, ToolSnapshot } from "@/lib/tools/interfaces";
 import {
   validateToolDefinition,
@@ -243,40 +243,31 @@ function FormContent({
             `Specify an OpenAPI schema that defines the APIs you want to make available as part of this action. Learn more about [OpenAPI actions](${DOCS_ADMINS_PATH}/actions/openapi).`
           )}
         >
-          <Hoverable.Root group="definitionField" widthVariant="full">
-            <div className="relative w-full">
-              {values.definition.trim() && (
-                <div className="absolute z-[100000] top-2 right-2 bg-background-tint-00">
-                  <Hoverable.Item
-                    group="definitionField"
-                    variant="opacity-on-hover"
-                  >
-                    <div className="flex">
-                      <CopyIconButton
-                        prominence="tertiary"
-                        size="sm"
-                        getCopyText={() => values.definition}
-                        tooltip="Copy definition"
-                      />
-                      <Button
-                        prominence="tertiary"
-                        size="sm"
-                        icon={SvgBracketCurly}
-                        tooltip="Format definition"
-                        onClick={handleFormat}
-                      />
-                    </div>
-                  </Hoverable.Item>
-                </div>
-              )}
-              <InputTextAreaField
-                name="definition"
-                rows={14}
-                placeholder="Enter your OpenAPI schema here"
-                className="font-main-ui-mono"
-              />
-            </div>
-          </Hoverable.Root>
+          <div className="group/DefinitionTextAreaField relative w-full">
+            {values.definition.trim() && (
+              <div className="invisible group-hover/DefinitionTextAreaField:visible absolute z-[100000] top-2 right-2 bg-background-tint-00">
+                <CopyIconButton
+                  prominence="tertiary"
+                  size="sm"
+                  getCopyText={() => values.definition}
+                  tooltip="Copy definition"
+                />
+                <Button
+                  prominence="tertiary"
+                  size="sm"
+                  icon={SvgBracketCurly}
+                  tooltip="Format definition"
+                  onClick={handleFormat}
+                />
+              </div>
+            )}
+            <InputTextAreaField
+              name="definition"
+              rows={14}
+              placeholder="Enter your OpenAPI schema here"
+              className="font-main-ui-mono"
+            />
+          </div>
         </InputLayouts.Vertical>
 
         <Separator noPadding />

web/src/sections/cards/AgentCard.tsx

@@ -127,10 +127,9 @@ export default function AgentCard({ agent }: AgentCardProps) {
         {fullAgent && <AgentViewerModal agent={fullAgent} />}
       </agentViewerModal.Provider>
 
-      <Interactive.Stateless
+      <Interactive.Simple
         onClick={() => agentViewerModal.toggle(true)}
         group="group/AgentCard"
-        variant="none"
       >
         <Card
           padding={0}
@@ -232,7 +231,7 @@ export default function AgentCard({ agent }: AgentCardProps) {
             </div>
           </div>
         </Card>
-      </Interactive.Stateless>
+      </Interactive.Simple>
     </>
   );
 }

web/src/sections/cards/DocumentSetCard.tsx

@@ -29,13 +29,12 @@ export default function DocumentSetCard({
       disabled={!disabled || !disabledTooltip}
     >
       <div className="max-w-[12rem]">
-        <Interactive.Stateless
+        <Interactive.Simple
           onClick={
             disabled || isSelected === undefined
               ? undefined
               : () => onSelectToggle?.(!isSelected)
           }
-          variant="none"
         >
           <Interactive.Container
             data-testid={`document-set-card-${documentSet.id}`}
@@ -64,7 +63,7 @@ export default function DocumentSetCard({
             />
             <Spacer horizontal rem={0.5} />
           </Interactive.Container>
-        </Interactive.Stateless>
+        </Interactive.Simple>
       </div>
     </SimpleTooltip>
   );

web/src/sections/cards/FileCard.tsx

@@ -6,7 +6,7 @@ import { UserFileStatus } from "@/app/app/projects/projectsService";
 import { cn, isImageFile } from "@/lib/utils";
 import SimpleLoader from "@/refresh-components/loaders/SimpleLoader";
 import { SvgFileText, SvgX } from "@opal/icons";
-import { Interactive, Hoverable } from "@opal/core";
+import { Interactive } from "@opal/core";
 import { AttachmentItemLayout } from "@/layouts/general-layouts";
 import Spacer from "@/refresh-components/Spacer";
 
@@ -21,39 +21,29 @@ function Removable({ onRemove, children }: RemovableProps) {
   }
 
   return (
-    <Hoverable.Root group="fileCard" widthVariant="fit">
-      <div className="relative">
-        <div
-          className={cn(
-            "absolute -left-2 -top-2 z-10",
-            "pointer-events-none focus-within:pointer-events-auto"
-          )}
-        >
-          <Hoverable.Item group="fileCard" variant="opacity-on-hover">
-            <button
-              type="button"
-              onClick={(e) => {
-                e.stopPropagation();
-                onRemove();
-              }}
-              title="Remove"
-              aria-label="Remove"
-              className={cn(
-                "h-4 w-4",
-                "flex items-center justify-center",
-                "rounded-04 border border-border text-[11px]",
-                "bg-background-neutral-inverted-01 text-text-inverted-05 shadow-sm",
-                "pointer-events-auto",
-                "hover:opacity-90"
-              )}
-            >
-              <SvgX className="h-3 w-3 stroke-text-inverted-03" />
-            </button>
-          </Hoverable.Item>
-        </div>
-        {children}
-      </div>
-    </Hoverable.Root>
+    <div className="relative group">
+      <button
+        type="button"
+        onClick={(e) => {
+          e.stopPropagation();
+          onRemove();
+        }}
+        title="Remove"
+        aria-label="Remove"
+        className={cn(
+          "absolute -left-2 -top-2 z-10 h-4 w-4",
+          "flex items-center justify-center",
+          "rounded-04 border border-border text-[11px]",
+          "bg-background-neutral-inverted-01 text-text-inverted-05 shadow-sm",
+          "opacity-0 group-hover:opacity-100 focus:opacity-100",
+          "pointer-events-none group-hover:pointer-events-auto focus:pointer-events-auto",
+          "transition-opacity duration-150 hover:opacity-90"
+        )}
+      >
+        <SvgX className="h-3 w-3 stroke-text-inverted-03" />
+      </button>
+      {children}
+    </div>
   );
 }
 

web/src/sections/modals/FeedbackModal.tsx

@@ -80,7 +80,7 @@ export default function FeedbackModal({
                   <InputLayouts.Vertical
                     name="additional_feedback"
                     title="Provide Additional Details"
-                    optional={feedbackType === "like"}
+                    suffix={feedbackType === "like" ? "optional" : undefined}
                   >
                     <InputTextAreaField
                       name="additional_feedback"

web/src/sections/modals/llmConfig/BifrostModal.tsx

@@ -126,7 +126,7 @@ function BifrostModalInternals({
         <InputLayouts.Vertical
           name="api_key"
           title="API Key"
-          optional={true}
+          suffix="optional"
           subDescription={markdown(
             "Paste your API key from [Bifrost](https://docs.getbifrost.ai/overview) to access your models."
           )}