[Fix] Slack tasks post duplicate kickoff messages

apps/api/src/handlers/artifacts/upload-complete.ts

@@ -1,6 +1,7 @@
 import type { Context } from 'hono';
 
 import { db, eq, taskArtifacts } from '@roomote/db/server';
+import { notifyFastAgentParentOnArtifact } from '@roomote/sdk/server';
 
 import type { Variables } from '../../types';
 import {
@@ -52,5 +53,30 @@ export async function markArtifactUploadComplete(
     })
     .where(eq(taskArtifacts.id, artifactId));
 
+  const notification = await notifyFastAgentParentOnArtifact({
+    id: artifact.id,
+    taskId: artifact.taskId,
+    runId: artifact.runId,
+    path: artifact.path,
+    version: artifact.version,
+    contentType: artifact.contentType,
+    uploaded: true,
+  });
+  if (notification === 'failed') {
+    return c.json(
+      { error: 'Artifact published, but parent notification failed' },
+      503,
+    );
+  }
+  if (notification === 'in_progress') {
+    // Another request is mid-delivery; 503 keeps the worker retrying until
+    // that delivery settles instead of reporting success while it can still
+    // fail and release its claim.
+    return c.json(
+      { error: 'Artifact published; parent notification is in progress' },
+      503,
+    );
+  }
+
   return new Response(null, { status: 200 });
 }

apps/api/src/handlers/slack/constants.ts

@@ -20,10 +20,8 @@ export const SLACK_EVENT_DEDUP_PREFIX = 'slack:event:';
 export const SLACK_WORKFLOW_COMPLETION_PREFIX = 'slack:workflow-completion:';
 export const SLACK_WORKFLOW_COMPLETION_TTL_SECONDS = 24 * 60 * 60;
 export const ROUTING_LOCK_TTL_SECONDS = 60;
-export const FAST_AGENT_LOCK_TTL_SECONDS = 600;
 export const SLACK_WELCOME_MESSAGE_CHANNEL_LIMIT = 3;
 export const SLACK_ROUTING_LOCK_PREFIX = 'slack:routing-lock:';
-export const SLACK_FAST_AGENT_LOCK_PREFIX = 'slack:fast-agent-lock:';
 export const SLACK_SETUP_SUGGESTION_LOCK_PREFIX =
   'slack:setup-suggestion-reaction:';
 export const LEADING_FAST_COMMAND_MENTION_PATTERN = /^\s*<@[^>]+>[\s,:;.-]*/;