# Documenter — F-029 Observability: traces and business metrics

## Summary
Observability module provides Tracer/Meter abstractions with in-process no-op implementations, a /ops/metrics route for admin, and business metric instrumentation on the checkout path.

## API

| Route | Access | Result |
|---|---|---|
| GET /ops/metrics | admin | Returns metrics snapshot |

## Interfaces
- Tracer.startSpan(name)/trace(name, fn)
- Meter.counter/histogram

## Evidence
- work/artifacts/F-029/architect.md
- work/artifacts/F-029/implementer.md
- work/artifacts/F-029/reviewer.json
- work/artifacts/F-029/security.json
- work/artifacts/F-029/qa.json