RateLint -- Rate Limiting & API Throttling Anti-Pattern Analyzer
RateLint scans codebases for rate limiting anti-patterns, missing throttling middleware, brute force exposure, unprotected endpoints, missing backoff strategies, unbounded queues, retry storm vulnerability, and flow control gaps. It uses regex-based pattern matching against 90 rate-limiting-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)
ratelint scan [file|directory]
One-shot rate limiting quality 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 rate limiting quality patterns against each file (free tier limit)
- Calculates a rate limiting quality 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 rate limiting quality is poor
- Free tier limited to first 30 patterns (RL + BF categories)
Example usage scenarios:
- "Scan my code for missing rate limits" -> runs
ratelint scan .
- "Check this file for throttling issues" -> runs
ratelint scan src/server.ts
- "Find brute force exposure" -> runs
ratelint scan src/
- "Audit rate limiting in my project" -> runs
ratelint scan .
- "Check for missing API throttling" -> runs
ratelint scan .
Pro Tier ($19/user/month -- requires RATELINT_LICENSE_KEY)
ratelint scan --tier pro [file|directory]
Extended scan with 60 patterns covering rate limiting, brute force, throttling, and backoff.
How to execute:
bash "<SKILL_DIR>/scripts/dispatcher.sh" --path [target] --tier pro
What it does:
- Validates Pro+ license
- Runs 60 rate limiting patterns (RL, BF, TH, BP categories)
- Detects missing throttling and backpressure patterns
- Identifies backoff and retry anti-patterns
- Full category breakdown reporting
ratelint scan --format json [directory]
Generate JSON output for CI/CD integration.
bash "<SKILL_DIR>/scripts/dispatcher.sh" --path [directory] --format json
ratelint scan --format html [directory]
Generate HTML report for browser viewing.
bash "<SKILL_DIR>/scripts/dispatcher.sh" --path [directory] --format html
ratelint scan --category TH [directory]
Filter scan to a specific check category (RL, BF, TH, BP, QO, DD).
bash "<SKILL_DIR>/scripts/dispatcher.sh" --path [directory] --category TH
Team Tier ($39/user/month -- requires RATELINT_LICENSE_KEY with team tier)
ratelint scan --tier team [directory]
Full scan with all 90 patterns across all 6 categories including queue overflow and retry backoff.
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 queue/buffer overflow checks (unbounded queues, missing max size)
- Includes retry & backoff checks (infinite retry loops, missing jitter, no circuit breaker)
- Full category breakdown with per-file results
ratelint scan --verbose [directory]
Verbose output showing every matched line and pattern details.
bash "<SKILL_DIR>/scripts/dispatcher.sh" --path [directory] --verbose
ratelint status
Show license and configuration information.
bash "<SKILL_DIR>/scripts/dispatcher.sh" status
Check Categories
RateLint detects 90 rate limiting anti-patterns across 6 categories:
| Category | Code | Patterns | Description | Severity Range |
|---|
| Rate Limit Configuration | RL | 15 | Missing rate limits on API endpoints, no limit headers, unbounded request acceptance, excessively high limits | medium -- critical |
| Brute Force Protection | BF | 15 | No login attempt limiting, missing account lockout, password reset flood, OTP brute force, disabled CAPTCHA | high -- critical |
| Throttling & Backpressure | TH | 15 | No request throttling, missing debounce, unbounded event handlers, no load shedding, disabled throttle | medium -- critical |
| Backoff & Retry | BP | 15 | No backpressure signaling, unbounded worker pools, missing flow control, disabled backpressure mechanisms | medium -- critical |
| Queue & Buffer Overflow | QO | 15 | Unbounded queues, no max queue size, memory exhaustion from queue growth, missing overflow handling | medium -- critical |
| DDoS & Abuse Prevention | DD | 15 | No exponential backoff, infinite retry loops, missing jitter, aggressive retry intervals, disabled circuit breaker | medium -- critical |
Tier-Based Pattern Access
| Tier | Patterns | Categories |
|---|
| Free | 30 | RL, BF |
| Pro | 60 | RL, BF, TH, BP |
| Team | 90 | RL, BF, TH, BP, QO, DD |
| Enterprise | 90 | RL, BF, TH, BP, QO, DD + priority support |
Scoring
RateLint uses a deductive scoring system starting at 100 (perfect):
| Severity | Point Deduction | Description |
|---|
| Critical | -25 per finding | Security vulnerability or guaranteed failure (unlimited retries, unbounded pools) |
| High | -15 per finding | Significant gap that will allow abuse (missing auth rate limit, no brute force protection) |
| Medium | -8 per finding | Moderate concern (missing throttle, no backoff strategy) |
| Low | -3 per finding | Informational / best practice suggestion |
Grading Scale
| Grade | Score Range | Meaning |
|---|
| A | 90-100 | Excellent rate limiting practices |
| B | 80-89 | Good practices with minor issues |
| C | 70-79 | Acceptable but needs improvement |
| D | 60-69 | Poor rate limiting quality |
| F | Below 60 | Critical throttling problems |
- Pass threshold: 70 (Grade C or better)
- Exit code 0 = pass (score >= 70)
- Exit code 1 = fail (score < 70)
Configuration
Users can configure RateLint in ~/.openclaw/openclaw.json:
{
"skills": {
"entries": {
"ratelint": {
"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://ratelint.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 RateLint
The user might say things like:
- "Scan my code for missing rate limits"
- "Check my API throttling"
- "Find brute force exposure"
- "Detect missing backoff strategies"
- "Are there any unthrottled endpoints?"
- "Check for missing rate limiting middleware"
- "Audit my rate limiting practices"
- "Find retry storm vulnerabilities"
- "Check for queue overflow risks"
- "Scan for rate limiting anti-patterns"
- "Run a rate limiting quality audit"
- "Generate a rate limiting quality report"
- "Check if my login endpoint has brute force protection"
- "Find endpoints without rate limits"
- "Check my code for missing exponential backoff"