fix: add error handling to APISearchAgent to prevent hanging requests

[octo-patch]

Fixes #1080

Problem

APISearchAgent.searchAsync had no try-catch block. When any error occurs during search (e.g., model provider failures, classification errors), no end or error event is emitted to the session. The /api/search route creates a Promise that waits for these events — when none arrive, the API request hangs indefinitely, returning no response to the client.

This results in unhandled rejections logged as:

⨯ unhandledRejection: Error: <message>

Solution

Wrap searchAsync in try-catch and emit an error event on failure, matching the existing pattern in SearchAgent (the chat UI agent) which already handles errors this way.

Testing

• Trigger an error in the search pipeline (e.g., use a misconfigured provider) via the /api/search endpoint
• Before fix: request hangs with no response
• After fix: request returns a 500 error response with the error message

---

Summary by cubic

Add error handling to both search agents and the reconnect flow to prevent hanging requests and stuck messages. Errors now emit proper events, update message status to error, and return a 500 instead of hanging.

• Bug Fixes
  • Wrap APISearchAgent.searchAsync in try/catch and emit a session error to prevent /api/search from hanging.
  • Wrap SearchAgent.searchAsync in try/catch; emit error and set the message’s DB status to error.
  • In useChat reconnect, check res.ok; on missing session (e.g., 404), stop loading and mark the last message as error.

^{Written for commit 6ccc07f. Summary will update on new commits.}

[cubic-dev-ai]

1 issue found across 3 files

Prompt for AI agents (unresolved issues)

Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately.


<file name="src/lib/hooks/useChat.tsx">

<violation number="1" location="src/lib/hooks/useChat.tsx:428">
P2: Reconnect flow lacks top-level fetch failure handling, which can leave reconnect/loading state stuck and reject unhandled.</violation>
</file>

_{Reply with feedback, questions, or to request a fix. Tag @cubic-dev-ai to re-run a review.}

[cubic-dev-ai]

P2: Reconnect flow lacks top-level fetch failure handling, which can leave reconnect/loading state stuck and reject unhandled.

Prompt for AI agents

Check if this issue is valid — if so, understand the root cause and fix it. At src/lib/hooks/useChat.tsx, line 428:

<comment>Reconnect flow lacks top-level fetch failure handling, which can leave reconnect/loading state stuck and reject unhandled.</comment>

<file context>
@@ -425,6 +425,20 @@ export const ChatProvider = ({ children }: { children: React.ReactNode }) => {
           method: 'POST',
         });
 
+        if (!res.ok) {
+          // Session no longer exists (e.g. server restarted) - mark message as error
+          setLoading(false);
</file context>