fix model defaults

web/src/app/chat/ChatPage.tsx

@@ -293,19 +293,22 @@ export function ChatPage({
     );
   };
 
-  const llmOverrideManager = useLlmOverride(
-    llmProviders,
-    user?.preferences.default_model,
-    selectedChatSession
-  );
-
   const [alternativeAssistant, setAlternativeAssistant] =
     useState<Persona | null>(null);
 
   const [presentingDocument, setPresentingDocument] =
     useState<OnyxDocument | null>(null);
 
-  const { recentAssistants, refreshRecentAssistants } = useAssistants();
+  const { recentAssistants, refreshRecentAssistants, assistants } =
+    useAssistants();
+
+  const llmOverrideManager = useLlmOverride(
+    llmProviders,
+    user?.preferences.default_model,
+    selectedChatSession,
+    undefined,
+    assistants
+  );
 
   const liveAssistant: Persona | undefined =
     alternativeAssistant ||
@@ -336,7 +339,7 @@ export function ChatPage({
       );
     }
     // eslint-disable-next-line react-hooks/exhaustive-deps
-  }, [liveAssistant, user?.preferences.default_model]);
+  }, [liveAssistant, user?.preferences.default_model, selectedChatSession]);
 
   const stopGenerating = () => {
     const currentSession = currentSessionId();

web/src/lib/hooks.ts

@@ -13,12 +13,16 @@ import { errorHandlingFetcher } from "./fetcher";
 import { useContext, useEffect, useState } from "react";
 import { DateRangePickerValue } from "@/app/ee/admin/performance/DateRangeSelector";
 import { Filters, SourceMetadata } from "./search/interfaces";
-import { destructureValue, structureValue } from "./llm/utils";
+import {
+  destructureValue,
+  getLLMProviderOverrideForPersona,
+  structureValue,
+} from "./llm/utils";
 import { ChatSession } from "@/app/chat/interfaces";
 import { AllUsersResponse } from "./types";
 import { Credential } from "./connectors/credentials";
 import { SettingsContext } from "@/components/settings/SettingsProvider";
-import { PersonaLabel } from "@/app/admin/assistants/interfaces";
+import { Persona, PersonaLabel } from "@/app/admin/assistants/interfaces";
 import { LLMProviderDescriptor } from "@/app/admin/configuration/llm/interfaces";
 import { isAnthropic } from "@/app/admin/configuration/llm/interfaces";
 import { getSourceMetadata } from "./sources";
@@ -367,7 +371,8 @@ export function useLlmOverride(
   llmProviders: LLMProviderDescriptor[],
   globalModel?: string | null,
   currentChatSession?: ChatSession,
-  defaultTemperature?: number
+  defaultTemperature?: number,
+  assistants?: Persona[]
 ): LlmOverrideManager {
   const getValidLlmOverride = (
     overrideModel: string | null | undefined
@@ -424,6 +429,32 @@ export function useLlmOverride(
     defaultTemperature !== undefined ? defaultTemperature : 0
   );
 
+  useEffect(() => {
+    const currentPersona = assistants?.find(
+      (a) => a.id === currentChatSession?.persona_id
+    );
+    const personaDefault = currentPersona
+      ? getLLMProviderOverrideForPersona(currentPersona, llmProviders)
+      : undefined;
+
+    if (personaDefault) {
+      updateLLMOverride(personaDefault);
+    } else {
+      updateLLMOverride(globalDefault);
+    }
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [currentChatSession]);
+
+  useEffect(() => {
+    if (currentChatSession?.current_alternate_model) {
+      setLlmOverride(
+        getValidLlmOverride(currentChatSession.current_alternate_model)
+      );
+    } else {
+      setLlmOverride(globalDefault);
+    }
+  }, [currentChatSession]);
+
   useEffect(() => {
     setGlobalDefault(getValidLlmOverride(globalModel));
   }, [globalModel, llmProviders]);