fix: background task completion detection and silent notifications

[Gladdonilli]

Summary

• Fix background tasks that hang indefinitely due to missing sessionStatus in polling loop
• Add silent notification system that injects completion messages into tool output instead of interrupting chat
• Fix TypeScript TS2742 errors with explicit ToolDefinition type annotations

Changes

Completion Detection (PR #592 re-implementation)

• Remove early continue when sessionStatus is undefined - allows fall-through to message-based detection
• Add stability detection: complete when message count unchanged for 3 consecutive polls (after 10s minimum runtime)
• Add lastMsgCount and stablePolls fields to BackgroundTask interface
• Add MIN_STABILITY_TIME_MS constant (10 seconds)

Silent Notification System (new feature)

• Add PendingNotification interface and pendingNotifications map to BackgroundManager
• Add hasPendingNotifications() and consumePendingNotifications() methods
• Replace session.prompt() with storing notifications for later injection
• Add tool.execute.after hook handler that injects pending notifications into tool output
• Wire up hook in src/index.ts

Other Fixes

• Change task retention from 200ms to 5 minutes for background_output retrieval
• Fix formatTaskResult to sort messages by time descending (matches sync pattern)
• Add String() wrapper for localeCompare to handle non-string time values
• Fix TS2742 by adding explicit ToolDefinition type annotations to skill and slashcommand exports

Testing

• Tested with 8 parallel background tasks (4 quick + 4 explore)
• All tasks complete in ~14-15 seconds
• Silent notifications successfully injected into tool output
• bun run typecheck passes
• bun run build succeeds

Files Modified

File	Change
src/features/background-agent/types.ts	Add lastMsgCount, stablePolls fields
src/features/background-agent/manager.ts	Add stability detection, silent notification storage, 5-min retention
src/features/background-agent/index.ts	Export PendingNotification type
src/hooks/background-notification/index.ts	Add tool.execute.after handler
src/index.ts	Wire up notification hook
src/tools/background-task/tools.ts	Fix formatTaskResult sorting
src/tools/skill/tools.ts	Add : ToolDefinition type annotation
src/tools/slashcommand/tools.ts	Add : ToolDefinition type annotation

---

Summary by cubic

Fixes background tasks that could hang and adds silent, inline notifications injected into tool outputs. Improves completion detection, keeps results available longer, and resolves TypeScript typing errors.

• Bug Fixes

  • Allow message-based completion when sessionStatus is missing.
  • Add stability detection (complete after 3 unchanged polls, after 10s).
  • Retain completed tasks for 5 minutes for background_output retrieval.
  • Sort assistant messages by newest first; handle non-string times safely.

• New Features

  • Silent notifications: store pending messages and inject them via a tool.execute.after hook (no chat interruption).
  • Export PendingNotification and add hasPendingNotifications/consumePendingNotifications helpers.
  • Add explicit ToolDefinition annotations for skill and slashcommand to fix TS2742.

^{Written for commit 9e81260. Summary will update on new commits.}

[chatgpt-codex-connector]

You have reached your Codex usage limits for code reviews. You can see your limits in the Codex usage dashboard.
To continue using code reviews, you can upgrade your account or add credits to your account and enable them for code reviews in your settings.

[greptile-apps]

Your free trial has ended. If you'd like to continue receiving code reviews, you can add a payment method here.

[cubic-dev-ai]

No issues found across 8 files

Confidence score: 5/5

• Automated review surfaced no issues in the provided summaries.
• No files require special attention.

[Gladdonilli]

new alternative method found + more issues identified, moving to a new pr