endpoint-validator

Endpoint Validator Skill

Deterministic HTTP endpoint validation: discover config, test each endpoint against expectations, report pass/fail with CI-compatible exit codes.

Deep References

Load on demand when the signal matches.

Signal	Reference	Content
Security header WARNs, HSTS/CSP/X-Frame	references/security-headers.md	Header checks, required values, remediation
Config errors, hardcoded IPs, timeouts	references/endpoint-config-preferred-patterns.md	Configuration failure modes and fixes
401/403 failures, auth patterns	references/auth-endpoint-patterns.md	Bearer, API-key, cookie auth validation

Instructions

Phase 1: DISCOVER

Read repository CLAUDE.md for base URL conventions or env var names.

Search for endpoint config in order: endpoints.json in project root, tests/endpoints.json, inline specification from user. Prefer version-controlled config over ad-hoc lists.

Config shape:

{
  "base_url": "http://localhost:8000",
  "endpoints": [
    {"path": "/health", "expect_status": 200},
    {"path": "/api/v1/users", "expect_key": "data", "timeout": 10},
    {"path": "/api/v1/search?q=test", "max_time": 2.0}
  ]
}

Endpoint fields: path (required), expect_status (default 200), expect_key (top-level JSON key), timeout (default 5s), max_time (SLOW threshold), method (default GET), headers (per-endpoint).

Rules:

• Warn before POST/PUT/DELETE against production base URLs.
• Use hostnames or ${ENV_VAR} in base_url, not hardcoded IPs.
• Confirm base URL reachable before the full suite.

Gate: config parsed, base URL reachable, at least one endpoint defined.

Phase 2: VALIDATE

Execute, do not reason. Run the request. Paste the exit code and output.

Test endpoints sequentially. For each:

1. Send request with configured method and timeout.
2. Check status code against expect_status. Mismatch -> FAIL.
3. If expect_key set, parse JSON and check key exists. Missing/invalid -> FAIL.
4. If max_time set and elapsed exceeds it -> SLOW.
5. On non-localhost URLs, check security headers (HSTS, CSP, X-Content-Type-Options, X-Frame-Options). Missing -> WARN (not FAIL). Skip HSTS on HTTP-only base URLs. Skip X-Frame-Options if CSP has frame-ancestors.