Greptile Overview

Greptile Summary

Added async_mode parameter to the hook system that enables hooks to run in background daemon threads without blocking the main execution flow.

Key changes:

• Added async_mode field to Hook dataclass (default: False)
• Modified HookRegistry.trigger to separate sync and async hooks, launching async ones in daemon threads
• Implemented _run_async_hook method with proper error handling and logging
• Added async_mode parameter to all register_hook type overloads
• Async hooks have their messages logged but not yielded to the caller
• Daemon threads are used intentionally for non-blocking side effects (logging, telemetry) where completion guarantees aren't required
• Comprehensive test coverage for async execution, error handling, and registration

Confidence Score: 4/5

• This PR is safe to merge with minimal risk
• The implementation is well-designed with proper error handling, comprehensive tests, and addresses all previously raised review concerns. The use of daemon threads is appropriately documented for the intended use cases (logging, telemetry). The changes are backward compatible and follow the existing codebase patterns.
• No files require special attention

Important Files Changed

Sequence Diagram

sequenceDiagram
    participant Client
    participant HookRegistry
    participant SyncHook
    participant AsyncHook
    participant Thread

    Client->>HookRegistry: trigger(hook_type, args, kwargs)
    HookRegistry->>HookRegistry: Separate sync and async hooks
    
    par Async Hooks (Fire-and-Forget)
        loop For each async hook
            HookRegistry->>Thread: Start daemon thread
            Thread->>AsyncHook: _run_async_hook(hook, args, kwargs)
            AsyncHook->>AsyncHook: Execute hook function
            AsyncHook->>AsyncHook: Log messages (not yielded)
            AsyncHook->>AsyncHook: Handle errors (caught, logged)
            Note over AsyncHook: Runs in background<br/>without blocking
        end
    and Sync Hooks (Sequential)
        loop For each sync hook
            HookRegistry->>SyncHook: hook.func(args, kwargs)
            SyncHook-->>HookRegistry: Yield messages
            Note over HookRegistry,SyncHook: Check for StopPropagation
            alt StopPropagation
                SyncHook-->>Client: Stop and return
            end
        end
        HookRegistry-->>Client: Yield all sync messages
    end
    
    Note over Thread,AsyncHook: Async hooks continue<br/>in background after<br/>client receives response

Codecov Report

❌ Patch coverage is 27.77778% with 26 lines in your changes missing coverage. Please review.
✅ All tests successful. No failed tests found.

📢 Thoughts on this report? Let us know!

✅ All Greptile Review Comments Addressed

Pushed fix in commit 6dbee5e:

Fixes Applied:

1. String slicing safety (x2): Added helper that handles empty/non-string content gracefully with preview truncation
2. SessionCompleteException handling: Added special-case handling in async hooks (logs info message, cannot propagate from background thread)
3. daemon=True documentation: Added comment explaining this is intentional for non-blocking side effects

All review threads have individual replies. Ready for re-review!

@greptileai review