From 4a503ecf4c9e1c855f54776e4ef256b9ce67ba45 Mon Sep 17 00:00:00 2001
From: Naiyuan Qing <145280634+NevilleQingNY@users.noreply.github.com>
Date: Fri, 6 Feb 2026 19:35:32 +0800
Subject: [PATCH] feat(agent): add AgentErrorEvent for error propagation via
 subscribe

Add agent_error event type to MulticaEvent union so errors from
agent runs reach subscribe() consumers (Desktop IPC + Channel).
Make emitMulticaEvent public on Runner so AsyncAgent can emit errors.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
---
 src/agent/async-agent.ts | 4 ++++
 src/agent/events.ts      | 8 +++++++-
 src/agent/runner.ts      | 2 +-
 3 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/src/agent/async-agent.ts b/src/agent/async-agent.ts
index db22b843..910e2742 100644
--- a/src/agent/async-agent.ts
+++ b/src/agent/async-agent.ts
@@ -48,12 +48,16 @@ export class AsyncAgent {
         await this.agent.flushSession();
         // Normal text is delivered via message_end event; only handle errors here
         if (result.error) {
+          console.error(`[AsyncAgent] Agent run error: ${result.error}`);
           this.channel.send({ id: uuidv7(), content: `[error] ${result.error}` });
+          this.agent.emitMulticaEvent({ type: "agent_error", error: result.error });
         }
       })
       .catch((err) => {
         const message = err instanceof Error ? err.message : String(err);
+        console.error(`[AsyncAgent] Agent run exception: ${message}`);
         this.channel.send({ id: uuidv7(), content: `[error] ${message}` });
+        this.agent.emitMulticaEvent({ type: "agent_error", error: message });
       });
   }
 
diff --git a/src/agent/events.ts b/src/agent/events.ts
index 8eb8b422..de46f02a 100644
--- a/src/agent/events.ts
+++ b/src/agent/events.ts
@@ -26,5 +26,11 @@ export type CompactionEndEvent = {
   reason: "count" | "tokens" | "summary" | "pruning";
 };
 
+/** Emitted when the agent encounters an error (LLM failure, quota exceeded, etc.) */
+export type AgentErrorEvent = {
+  type: "agent_error";
+  error: string;
+};
+
 /** Union of all Multica-specific events */
-export type MulticaEvent = CompactionStartEvent | CompactionEndEvent;
+export type MulticaEvent = CompactionStartEvent | CompactionEndEvent | AgentErrorEvent;
diff --git a/src/agent/runner.ts b/src/agent/runner.ts
index 65fd528b..479cd473 100644
--- a/src/agent/runner.ts
+++ b/src/agent/runner.ts
@@ -342,7 +342,7 @@ export class Agent {
     };
   }
 
-  private emitMulticaEvent(event: MulticaEvent): void {
+  emitMulticaEvent(event: MulticaEvent): void {
     for (const fn of this.multicaListeners) {
       try {
         fn(event);