fix(ui): show active assistant model in status

packages/ui/src/components/chat/StatusRowContainer.tsx

@@ -21,21 +21,19 @@ export const StatusRowContainer: React.FC = React.memo(() => {
             return state.sessionAbortFlags?.get(currentSessionId) ?? null;
         }, [currentSessionId]),
     );
-    const { working } = useAssistantStatus();
+    const { activeModel, working } = useAssistantStatus();
     const currentAgentName = useConfigStore((state) => state.currentAgentName);
-    const currentProviderId = useConfigStore((state) => state.currentProviderId);
-    const currentModelId = useConfigStore((state) => state.currentModelId);
     const providers = useConfigStore((state) => state.providers);
 
     const modelDisplayName = React.useMemo(() => {
-        if (!currentModelId) {
+        if (!activeModel) {
             return null;
         }
-        const provider = currentProviderId && providers.length > 0
-            ? providers.find((candidate) => candidate.id === currentProviderId)
+        const provider = providers.length > 0
+            ? providers.find((candidate) => candidate.id === activeModel.providerId)
             : undefined;
-        return getProviderModelDisplayName(provider, currentModelId) || null;
-    }, [currentProviderId, currentModelId, providers]);
+        return getProviderModelDisplayName(provider, activeModel.modelId) || null;
+    }, [activeModel, providers]);
 
     const wasAborted = Boolean(abortRecord && !abortRecord.acknowledged);
 
@@ -52,7 +50,7 @@ export const StatusRowContainer: React.FC = React.memo(() => {
             showTodos={false}
             agentName={currentAgentName}
             modelName={modelDisplayName}
-            providerId={currentProviderId ?? null}
+            providerId={activeModel?.providerId ?? null}
         />
     );
 });

packages/ui/src/hooks/useAssistantStatus.test.ts

@@ -0,0 +1,60 @@
+import { describe, expect, test } from 'bun:test';
+import type { Message } from '@opencode-ai/sdk/v2';
+
+import { getActiveAssistantContext } from './useAssistantStatus';
+
+const userMessage = (id: string, providerID: string, modelID: string): Message => ({
+    id,
+    role: 'user',
+    sessionID: 'ses_1',
+    time: { created: 1 },
+    model: { providerID, modelID },
+} as Message);
+
+const assistantMessage = (id: string, parentID: string): Message => ({
+    id,
+    role: 'assistant',
+    sessionID: 'ses_1',
+    parentID,
+    time: { created: 2 },
+} as Message);
+
+describe('getActiveAssistantContext', () => {
+    test('uses the active assistant parent model instead of the latest user selection', () => {
+        const activeParent = userMessage('user_1', 'anthropic', 'claude-opus-4-1');
+        const assistant = assistantMessage('assistant_1', activeParent.id);
+        const laterSelection = userMessage('user_2', 'openai', 'gpt-5.6-sol');
+
+        expect(getActiveAssistantContext([activeParent, assistant, laterSelection])).toEqual({
+            assistantId: assistant.id,
+            model: {
+                providerId: 'anthropic',
+                modelId: 'claude-opus-4-1',
+            },
+        });
+    });
+
+    test('switches models only when a newer assistant links to the newer user message', () => {
+        const firstUser = userMessage('user_1', 'anthropic', 'claude-opus-4-1');
+        const firstAssistant = assistantMessage('assistant_1', firstUser.id);
+        const secondUser = userMessage('user_2', 'openai', 'gpt-5.6-sol');
+        const secondAssistant = assistantMessage('assistant_2', secondUser.id);
+
+        expect(getActiveAssistantContext([firstUser, firstAssistant, secondUser, secondAssistant])).toEqual({
+            assistantId: secondAssistant.id,
+            model: {
+                providerId: 'openai',
+                modelId: 'gpt-5.6-sol',
+            },
+        });
+    });
+
+    test('does not guess a model when the parent message is unavailable', () => {
+        const assistant = assistantMessage('assistant_1', 'missing_user');
+
+        expect(getActiveAssistantContext([assistant])).toEqual({
+            assistantId: assistant.id,
+            model: null,
+        });
+    });
+});

packages/ui/src/hooks/useAssistantStatus.ts

@@ -3,7 +3,7 @@ import type { Message, Part, ReasoningPart, TextPart, ToolPart } from '@opencode
 
 import type { MessageStreamPhase } from '@/stores/types/sessionTypes';
 import { useSessionUIStore } from '@/sync/session-ui-store';
-import { useDirectorySync, useSessionPermissions, useSessionQuestions, useSessionStatus } from '@/sync/sync-context';
+import { useDirectorySync, useSessionMessages, useSessionPermissions, useSessionQuestions, useSessionStatus } from '@/sync/sync-context';
 import { isFullySyntheticMessage } from '@/lib/messages/synthetic';
 import { useCurrentSessionActivity } from './useSessionActivity';
 
@@ -37,10 +37,21 @@ interface FormingSummary {
 }
 
 export interface AssistantStatusSnapshot {
+    activeModel: ActiveAssistantModel | null;
     forming: FormingSummary;
     working: WorkingSummary;
 }
 
+interface ActiveAssistantModel {
+    providerId: string;
+    modelId: string;
+}
+
+interface ActiveAssistantContext {
+    assistantId: string | null;
+    model: ActiveAssistantModel | null;
+}
+
 const DEFAULT_WORKING: WorkingSummary = {
     activity: 'idle',
     hasWorkingContext: false,
@@ -63,7 +74,6 @@ const DEFAULT_WORKING: WorkingSummary = {
     retryInfo: null,
 };
 
-const EMPTY_MESSAGES: Message[] = [];
 const EMPTY_PARTS: Part[] = [];
 const STATUS_SIGNATURE_SEPARATOR = '\u0000';
 const EDITING_TOOLS = new Set(['edit', 'write', 'multiedit', 'apply_patch']);
@@ -247,28 +257,63 @@ const getToolDisplayName = (part: ToolPart): string => {
     return typeof candidate.name === 'string' ? candidate.name : 'tool';
 };
 
+export const getActiveAssistantContext = (messages: Message[]): ActiveAssistantContext => {
+    let assistantId: string | null = null;
+    let parentId: string | null = null;
+
+    for (let index = messages.length - 1; index >= 0; index -= 1) {
+        const message = messages[index];
+        if (message?.role !== 'assistant') continue;
+
+        const candidate = message as Message & { parentID?: unknown };
+        assistantId = message.id;
+        parentId = typeof candidate.parentID === 'string' && candidate.parentID.trim().length > 0
+            ? candidate.parentID
+            : null;
+        break;
+    }
+
+    if (!assistantId || !parentId) {
+        return { assistantId, model: null };
+    }
+
+    for (let index = messages.length - 1; index >= 0; index -= 1) {
+        const message = messages[index];
+        if (message?.role !== 'user' || message.id !== parentId) continue;
+
+        const candidate = message as Message & {
+            model?: { providerID?: unknown; modelID?: unknown };
+        };
+        const providerId = typeof candidate.model?.providerID === 'string'
+            ? candidate.model.providerID.trim()
+            : '';
+        const modelId = typeof candidate.model?.modelID === 'string'
+            ? candidate.model.modelID.trim()
+            : '';
+
+        return {
+            assistantId,
+            model: providerId && modelId ? { providerId, modelId } : null,
+        };
+    }
+
+    return { assistantId, model: null };
+};
+
 export function useAssistantStatus(): AssistantStatusSnapshot {
     const currentSessionId = useSessionUIStore((state) => state.currentSessionId);
     const currentSessionDirectory = useSessionUIStore((state) => state.currentSessionDirectory);
 
-    const rawSessionMessages = useDirectorySync(
-        React.useCallback((state) => {
-            if (!currentSessionId) {
-                return EMPTY_MESSAGES;
-            }
-            return state.message[currentSessionId] ?? EMPTY_MESSAGES;
-        }, [currentSessionId]),
+    const rawSessionMessages = useSessionMessages(
+        currentSessionId ?? '',
         currentSessionDirectory ?? undefined,
     );
 
-    // Only subscribe to parts for the last assistant message — avoids re-render
-    // on every part delta for earlier messages.
-    const lastAssistantId = React.useMemo(() => {
-        for (let i = rawSessionMessages.length - 1; i >= 0; i--) {
-            if (rawSessionMessages[i].role === 'assistant') return rawSessionMessages[i].id;
-        }
-        return null;
-    }, [rawSessionMessages]);
+    const activeAssistant = React.useMemo(
+        () => getActiveAssistantContext(rawSessionMessages),
+        [rawSessionMessages],
+    );
+    const lastAssistantId = activeAssistant.assistantId;
 
     const lastAssistantStatusSignature = useDirectorySync(
         React.useCallback((state) => {
@@ -412,6 +457,7 @@ export function useAssistantStatus(): AssistantStatusSnapshot {
     }, [baseWorking, sessionPermissionRequests, sessionQuestionRequests]);
 
     return {
+        activeModel: activeAssistant.model,
         forming,
         working,
     };