AsyncGuard -- Async/Await Anti-Pattern Analyzer
AsyncGuard scans codebases for async/await anti-patterns, promise misuse, async resource leaks, event loop blocking, missing cancellation support, async error handling gaps, and coordination issues. It uses regex-based pattern matching against 90 async-specific patterns across 6 categories, lefthook for git hook integration, and produces markdown reports with actionable remediation guidance. 100% local. Zero telemetry.
Commands
Free Tier (No license required)
asyncguard scan [file|directory]
One-shot async safety scan of files or directories.
How to execute:
bash "<SKILL_DIR>/scripts/dispatcher.sh" --path [target]
What it does:
- Accepts a file path or directory (defaults to current directory)
- Discovers all source files (skips .git, node_modules, binaries, images, .min.js)
- Runs 30 async patterns against each file (free tier limit)
- Calculates an async safety score (0-100) per file and overall
- Grades: A (90-100), B (80-89), C (70-79), D (60-69), F (<60)
- Outputs findings with: file, line number, check ID, severity, description, recommendation
- Exit code 0 if score >= 70, exit code 1 if async quality is poor
- Free tier limited to first 30 patterns (PM + AR categories)
Example usage scenarios:
- "Scan my code for async issues" -> runs
asyncguard scan .
- "Check this file for promise misuse" -> runs
asyncguard scan src/server.ts
- "Find resource leaks in my async code" -> runs
asyncguard scan src/
- "Audit async patterns in my project" -> runs
asyncguard scan .
- "Check for missing cancellation" -> runs
asyncguard scan .
Pro Tier ($19/user/month -- requires ASYNCGUARD_LICENSE_KEY)
asyncguard scan --tier pro [file|directory]
Extended scan with 60 patterns covering promise misuse, resource leaks, event loop blocking, and cancellation.
How to execute:
bash "<SKILL_DIR>/scripts/dispatcher.sh" --path [target] --tier pro
What it does:
- Validates Pro+ license
- Runs 60 async patterns (PM, AR, EL, CA categories)
- Detects event loop blocking (sync I/O, sync crypto)
- Identifies missing cancellation and abort handling
- Full category breakdown reporting
asyncguard scan --format json [directory]
Generate JSON output for CI/CD integration.
bash "<SKILL_DIR>/scripts/dispatcher.sh" --path [directory] --format json
asyncguard scan --format html [directory]
Generate HTML report for browser viewing.
bash "<SKILL_DIR>/scripts/dispatcher.sh" --path [directory] --format html
asyncguard scan --category EL [directory]
Filter scan to a specific check category (PM, AR, EL, CA, AE, AC).
bash "<SKILL_DIR>/scripts/dispatcher.sh" --path [directory] --category EL
Team Tier ($39/user/month -- requires ASYNCGUARD_LICENSE_KEY with team tier)
asyncguard scan --tier team [directory]
Full scan with all 90 patterns across all 6 categories including async error patterns and coordination.
How to execute:
bash "<SKILL_DIR>/scripts/dispatcher.sh" --path [directory] --tier team
What it does:
- Validates Team+ license
- Runs all 90 patterns across 6 categories
- Includes async error pattern detection (swallowed rejections, async forEach, empty catch)
- Includes coordination checks (unbounded concurrency, missing backpressure, no rate limit)
- Full category breakdown with per-file results
asyncguard scan --verbose [directory]
Verbose output showing every matched line and pattern details.
bash "<SKILL_DIR>/scripts/dispatcher.sh" --path [directory] --verbose
asyncguard status
Show license and configuration information.
bash "<SKILL_DIR>/scripts/dispatcher.sh" status
Check Categories
AsyncGuard detects 90 async anti-patterns across 6 categories:
| Category |
Code |
Patterns |
Description |
Severity Range |
| Promise/Future Misuse |
PM |
15 |
Unhandled promises, async executor, nested .then chains, deferred antipattern |
medium -- critical |
| Async Resource Leaks |
AR |
15 |
Unclosed connections, missing dispose, dangling streams, leaked timers |
medium -- critical |
| Event Loop Blocking |
EL |
15 |
Sync file I/O, sync crypto, CPU loops, sync child process |
low -- critical |
| Cancellation & Abortion |
CA |
15 |
Missing AbortSignal, orphaned tasks, no cleanup on unmount |
medium -- critical |
| Async Error Patterns |
AE |
15 |
Swallowed rejections, empty .catch, async forEach, missing try/catch |
medium -- critical |
| Async Coordination |
AC |
15 |
Unbounded Promise.all, missing semaphore, no backpressure, no rate limit |
medium -- critical |
Tier-Based Pattern Access
| Tier |
Patterns |
Categories |
| Free |
30 |
PM, AR |
| Pro |
60 |
PM, AR, EL, CA |
| Team |
90 |
PM, AR, EL, CA, AE, AC |
| Enterprise |
90 |
PM, AR, EL, CA, AE, AC + priority support |
Scoring
AsyncGuard uses a deductive scoring system starting at 100 (perfect):
| Severity |
Point Deduction |
Description |
| Critical |
-25 per finding |
Severe async issue (resource leaks, unhandled rejections, blocking I/O) |
| High |
-15 per finding |
Significant async problem (missing cancellation, no error handler) |
| Medium |
-8 per finding |
Moderate concern (coordination issues, missing backpressure) |
| Low |
-3 per finding |
Informational / best practice suggestion |
Grading Scale
| Grade |
Score Range |
Meaning |
| A |
90-100 |
Excellent async code quality |
| B |
80-89 |
Good async patterns with minor issues |
| C |
70-79 |
Acceptable but needs improvement |
| D |
60-69 |
Poor async quality |
| F |
Below 60 |
Critical async problems |
- Pass threshold: 70 (Grade C or better)
- Exit code 0 = pass (score >= 70)
- Exit code 1 = fail (score < 70)
Configuration
Users can configure AsyncGuard in ~/.openclaw/openclaw.json:
{
"skills": {
"entries": {
"asyncguard": {
"enabled": true,
"apiKey": "YOUR_LICENSE_KEY_HERE",
"config": {
"severityThreshold": "medium",
"ignorePatterns": ["**/test/**", "**/fixtures/**", "**/*.test.*"],
"ignoreChecks": [],
"reportFormat": "text"
}
}
}
}
}
Important Notes
- Free tier works immediately with no configuration
- All scanning happens locally -- no code is sent to external servers
- License validation is offline -- no phone-home or network calls
- Pattern matching only -- no AST parsing, no external dependencies beyond bash
- Supports scanning all file types in a single pass
- Git hooks use lefthook which must be installed (see install metadata above)
- Exit codes: 0 = pass (score >= 70), 1 = fail (for CI/CD integration)
- Output formats: text (default), json, html
Error Handling
- If lefthook is not installed and user tries hooks, prompt to install it
- If license key is invalid or expired, show clear message with link to https://asyncguard.pages.dev/renew
- If a file is binary, skip it automatically with no warning
- If no scannable files found in target, report clean scan with info message
- If an invalid category is specified with --category, show available categories
When to Use AsyncGuard
The user might say things like:
- "Scan my code for async issues"
- "Check my promise handling"
- "Find resource leaks in async code"
- "Detect event loop blocking"
- "Are there any missing cancellation handlers?"
- "Check for unhandled promise rejections"
- "Audit my async error handling"
- "Find missing AbortController usage"
- "Check for synchronous I/O in async functions"
- "Scan for async anti-patterns"
- "Run an async code audit"
- "Generate an async safety report"
- "Check if my fetch calls have abort signals"
- "Find empty catch handlers"
- "Check my code for async coordination issues"
1---2name: asyncguard3description: Async/await anti-pattern analyzer -- detects promise misuse, async resource leaks, event loop blocking, missing cancellation, async error patterns, and coordination issues4---5
6# AsyncGuard -- Async/Await Anti-Pattern Analyzer
7
8AsyncGuard scans codebases for async/await anti-patterns, promise misuse, async resource leaks, event loop blocking, missing cancellation support, async error handling gaps, and coordination issues. It uses regex-based pattern matching against 90 async-specific patterns across 6 categories, lefthook for git hook integration, and produces markdown reports with actionable remediation guidance. 100% local. Zero telemetry.
9
10## Commands
11
12### Free Tier (No license required)
13
14#### `asyncguard scan [file|directory]`
15One-shot async safety scan of files or directories.
16
17**How to execute:**
18```bash
19bash "<SKILL_DIR>/scripts/dispatcher.sh" --path [target]
20```
21
22**What it does:**
231. Accepts a file path or directory (defaults to current directory)
242. Discovers all source files (skips .git, node_modules, binaries, images, .min.js)
253. Runs 30 async patterns against each file (free tier limit)
264. Calculates an async safety score (0-100) per file and overall
275. Grades: A (90-100), B (80-89), C (70-79), D (60-69), F (<60)
286. Outputs findings with: file, line number, check ID, severity, description, recommendation
297. Exit code 0 if score >= 70, exit code 1 if async quality is poor
308. Free tier limited to first 30 patterns (PM + AR categories)
31
32**Example usage scenarios:**
33- "Scan my code for async issues" -> runs `asyncguard scan .`
34- "Check this file for promise misuse" -> runs `asyncguard scan src/server.ts`
35- "Find resource leaks in my async code" -> runs `asyncguard scan src/`
36- "Audit async patterns in my project" -> runs `asyncguard scan .`
37- "Check for missing cancellation" -> runs `asyncguard scan .`
38
39### Pro Tier ($19/user/month -- requires ASYNCGUARD_LICENSE_KEY)
40
41#### `asyncguard scan --tier pro [file|directory]`
42Extended scan with 60 patterns covering promise misuse, resource leaks, event loop blocking, and cancellation.
43
44**How to execute:**
45```bash
46bash "<SKILL_DIR>/scripts/dispatcher.sh" --path [target] --tier pro
47```
48
49**What it does:**
501. Validates Pro+ license
512. Runs 60 async patterns (PM, AR, EL, CA categories)
523. Detects event loop blocking (sync I/O, sync crypto)
534. Identifies missing cancellation and abort handling
545. Full category breakdown reporting
55
56#### `asyncguard scan --format json [directory]`
57Generate JSON output for CI/CD integration.
58
59```bash
60bash "<SKILL_DIR>/scripts/dispatcher.sh" --path [directory] --format json
61```
62
63#### `asyncguard scan --format html [directory]`
64Generate HTML report for browser viewing.
65
66```bash
67bash "<SKILL_DIR>/scripts/dispatcher.sh" --path [directory] --format html
68```
69
70#### `asyncguard scan --category EL [directory]`
71Filter scan to a specific check category (PM, AR, EL, CA, AE, AC).
72
73```bash
74bash "<SKILL_DIR>/scripts/dispatcher.sh" --path [directory] --category EL
75```
76
77### Team Tier ($39/user/month -- requires ASYNCGUARD_LICENSE_KEY with team tier)
78
79#### `asyncguard scan --tier team [directory]`
80Full scan with all 90 patterns across all 6 categories including async error patterns and coordination.
81
82**How to execute:**
83```bash
84bash "<SKILL_DIR>/scripts/dispatcher.sh" --path [directory] --tier team
85```
86
87**What it does:**
881. Validates Team+ license
892. Runs all 90 patterns across 6 categories
903. Includes async error pattern detection (swallowed rejections, async forEach, empty catch)
914. Includes coordination checks (unbounded concurrency, missing backpressure, no rate limit)
925. Full category breakdown with per-file results
93
94#### `asyncguard scan --verbose [directory]`
95Verbose output showing every matched line and pattern details.
96
97```bash
98bash "<SKILL_DIR>/scripts/dispatcher.sh" --path [directory] --verbose
99```
100
101#### `asyncguard status`
102Show license and configuration information.
103
104```bash
105bash "<SKILL_DIR>/scripts/dispatcher.sh" status
106```
107
108## Check Categories
109
110AsyncGuard detects 90 async anti-patterns across 6 categories:
111
112| Category | Code | Patterns | Description | Severity Range |
113|----------|------|----------|-------------|----------------|
114| **Promise/Future Misuse** | PM | 15 | Unhandled promises, async executor, nested .then chains, deferred antipattern | medium -- critical |
115| **Async Resource Leaks** | AR | 15 | Unclosed connections, missing dispose, dangling streams, leaked timers | medium -- critical |
116| **Event Loop Blocking** | EL | 15 | Sync file I/O, sync crypto, CPU loops, sync child process | low -- critical |
117| **Cancellation & Abortion** | CA | 15 | Missing AbortSignal, orphaned tasks, no cleanup on unmount | medium -- critical |
118| **Async Error Patterns** | AE | 15 | Swallowed rejections, empty .catch, async forEach, missing try/catch | medium -- critical |
119| **Async Coordination** | AC | 15 | Unbounded Promise.all, missing semaphore, no backpressure, no rate limit | medium -- critical |
120
121## Tier-Based Pattern Access
122
123| Tier | Patterns | Categories |
124|------|----------|------------|
125| **Free** | 30 | PM, AR |
126| **Pro** | 60 | PM, AR, EL, CA |
127| **Team** | 90 | PM, AR, EL, CA, AE, AC |
128| **Enterprise** | 90 | PM, AR, EL, CA, AE, AC + priority support |
129
130## Scoring
131
132AsyncGuard uses a deductive scoring system starting at 100 (perfect):
133
134| Severity | Point Deduction | Description |
135|----------|-----------------|-------------|
136| **Critical** | -25 per finding | Severe async issue (resource leaks, unhandled rejections, blocking I/O) |
137| **High** | -15 per finding | Significant async problem (missing cancellation, no error handler) |
138| **Medium** | -8 per finding | Moderate concern (coordination issues, missing backpressure) |
139| **Low** | -3 per finding | Informational / best practice suggestion |
140
141### Grading Scale
142
143| Grade | Score Range | Meaning |
144|-------|-------------|---------|
145| **A** | 90-100 | Excellent async code quality |
146| **B** | 80-89 | Good async patterns with minor issues |
147| **C** | 70-79 | Acceptable but needs improvement |
148| **D** | 60-69 | Poor async quality |
149| **F** | Below 60 | Critical async problems |
150
151- **Pass threshold:** 70 (Grade C or better)
152- Exit code 0 = pass (score >= 70)
153- Exit code 1 = fail (score < 70)
154
155## Configuration
156
157Users can configure AsyncGuard in `~/.openclaw/openclaw.json`:
158
159```json
160{
161 "skills": {
162 "entries": {
163 "asyncguard": {
164 "enabled": true,
165 "apiKey": "YOUR_LICENSE_KEY_HERE",
166 "config": {
167 "severityThreshold": "medium",
168 "ignorePatterns": ["**/test/**", "**/fixtures/**", "**/*.test.*"],
169 "ignoreChecks": [],
170 "reportFormat": "text"
171 }
172 }
173 }
174 }
175}
176```
177
178## Important Notes
179
180- **Free tier** works immediately with no configuration
181- **All scanning happens locally** -- no code is sent to external servers
182- **License validation is offline** -- no phone-home or network calls
183- Pattern matching only -- no AST parsing, no external dependencies beyond bash
184- Supports scanning all file types in a single pass
185- Git hooks use **lefthook** which must be installed (see install metadata above)
186- Exit codes: 0 = pass (score >= 70), 1 = fail (for CI/CD integration)
187- Output formats: text (default), json, html
188
189## Error Handling
190
191- If lefthook is not installed and user tries hooks, prompt to install it
192- If license key is invalid or expired, show clear message with link to https://asyncguard.pages.dev/renew
193- If a file is binary, skip it automatically with no warning
194- If no scannable files found in target, report clean scan with info message
195- If an invalid category is specified with --category, show available categories
196
197## When to Use AsyncGuard
198
199The user might say things like:
200- "Scan my code for async issues"
201- "Check my promise handling"
202- "Find resource leaks in async code"
203- "Detect event loop blocking"
204- "Are there any missing cancellation handlers?"
205- "Check for unhandled promise rejections"
206- "Audit my async error handling"
207- "Find missing AbortController usage"
208- "Check for synchronous I/O in async functions"
209- "Scan for async anti-patterns"
210- "Run an async code audit"
211- "Generate an async safety report"
212- "Check if my fetch calls have abort signals"
213- "Find empty catch handlers"
214- "Check my code for async coordination issues"