API Tracing

Measure API requests and correlate with backend traces.

What to Capture (OTel-Compatible)

| Attribute | OTel Name | Purpose | |-----------|-----------|---------| | Method | http.request.method | GET, POST, etc. | | Status | http.response.status_code | Success/failure | | URL | url.path | Endpoint (sanitized) | | Duration | http.request.duration | Request time (ms) |

Using OTel naming now = easier migration later.

Key Thresholds

| Metric | Good | Acceptable | Poor | |--------|------|------------|------| | p50 | <200ms | <500ms | >500ms | | p95 | <1s | <2s | >2s | | Error rate | <0.1% | <1% | >1% |

What NOT to Log

| Don't | Why | |-------|-----| | Request bodies | PII risk | | Auth headers | Security | | Full response data | Size limits | | User tokens | Security |

Do log: Request ID, sanitized path, status code, duration, error type.

Implementation

See templates/api-interceptor.ts for fetch/axios interceptors.

Use Read tool to load template when generating implementation.

Related

• skills/error-tracking - API error handling
• skills/route-transition-tracking - Data fetch during navigation
• references/otel-web.md - OpenTelemetry naming