Find unhandled promises, async resource leaks, event loop blocking, missing cancellation, and coordination issues — before they crash production.
Unhandled promises. Fire-and-forget awaits. Event loop blocked by readFileSync. AbortControllers that never abort. When the memory climbs and requests hang, it started here.
90 checks across 6 categories, covering every aspect of async logic and resource management.
Detects unhandled promises without .catch or await, fire-and-forget async calls, promise constructor anti-patterns, and unnecessary async functions that add overhead without benefit.
Catches missing AbortController cleanup in useEffect, unclosed streams and file handles, dangling timers without clearTimeout, and WebSocket connections that never close on unmount.
Finds readFileSync in async handlers, CPU-intensive loops without yielding, JSON.parse on massive payloads in the main thread, and crypto operations blocking request processing.
Detects fetch calls without AbortController, missing request cancellation on component unmount, absent timeout handling on long-running operations, and uncancellable async workflows.
Catches empty .catch() blocks swallowing errors silently, missing error boundaries for async components, rejected promises without logging, and error handling that loses stack traces.
Detects unbounded Promise.all with excessive concurrency, sequential awaits that should be parallel, race conditions in shared async state, and missing Promise.allSettled for partial failures.
Choose the plan that matches your async reliability requirements.
| Feature | Free | Pro | Team |
|---|---|---|---|
| Detection checks | 30 | 60 | 90 (all) |
| Promise Misuse (PM) | ✓ | ✓ | ✓ |
| Async Resource Leaks (AR) | ✓ | ✓ | ✓ |
| Event Loop Blocking (EL) | ✗ | ✓ | ✓ |
| Cancellation & Abortion (CA) | ✗ | ✓ | ✓ |
| Async Error Patterns (AE) | ✗ | ✗ | ✓ |
| Async Coordination (AC) | ✗ | ✗ | ✓ |
| Terminal report | ✓ | ✓ | ✓ |
| JSON / HTML report | ✗ | ✓ | ✓ |
| Category filtering | ✗ | ✓ | ✓ |
| Verbose output | ✗ | ✗ | ✓ |
| CI/CD integration | ✗ | ✗ | ✓ |
| Custom rules | ✗ | ✗ | ✓ |
| Support | Community | Priority |
Start scanning for free. Upgrade when your async reliability demands it.
No spam. One email per week max. Unsubscribe anytime.
Install AsyncGuard in 30 seconds. Find every unhandled promise, leaked resource, and blocked event loop before production does.