[claude] API observability — structured logging + /api/metrics endpoint (#57) #87

claude · 2026-03-23T20:09:12Z

claude commented

2026-03-23 20:09:12 +00:00

Fixes #57

Summary

Adds full API observability to the server with no external dependencies:

Structured logger (lib/logger.ts) — JSON log lines with timestamp, level, component, message, and optional context fields. LOG_LEVEL env var controls verbosity (debug/info/warn/error)
Latency histogram (lib/histogram.ts) — In-memory ring buffer (1000 samples/bucket) tracking p50/p95 per route key
Request counters (lib/request-counters.ts) — In-memory counters for total requests, by-status breakdown, 4xx/5xx error counts
Request-ID middleware (middlewares/request-id.ts) — Assigns X-Request-Id header (reuses upstream or generates UUID), echoed in response
Response-time middleware (middlewares/response-time.ts) — Records duration into histogram and counters, emits structured request log line per response
MetricsService (lib/metrics.ts) — Queries DB for job counts by state, invoice conversion rate, total sats earned; merges with in-memory latency and HTTP counter data
GET /api/metrics (routes/metrics.ts) — Returns full MetricsSnapshot JSON including uptime, http counters, jobs by state, invoice stats, earnings, and p50/p95 latency per route
GET /api/healthz extended (routes/health.ts) — Now returns { status, uptime_s, jobs_total } (non-breaking addition)
Structured logging adopted across all route and service files: jobs.ts, demo.ts, health.ts, agent.ts, lnbits.ts, rate-limiter.ts

Fixes #57 ## Summary Adds full API observability to the server with no external dependencies: - **Structured logger** (`lib/logger.ts`) — JSON log lines with `timestamp`, `level`, `component`, `message`, and optional context fields. `LOG_LEVEL` env var controls verbosity (debug/info/warn/error) - **Latency histogram** (`lib/histogram.ts`) — In-memory ring buffer (1000 samples/bucket) tracking p50/p95 per route key - **Request counters** (`lib/request-counters.ts`) — In-memory counters for total requests, by-status breakdown, 4xx/5xx error counts - **Request-ID middleware** (`middlewares/request-id.ts`) — Assigns `X-Request-Id` header (reuses upstream or generates UUID), echoed in response - **Response-time middleware** (`middlewares/response-time.ts`) — Records duration into histogram and counters, emits structured `request` log line per response - **MetricsService** (`lib/metrics.ts`) — Queries DB for job counts by state, invoice conversion rate, total sats earned; merges with in-memory latency and HTTP counter data - **`GET /api/metrics`** (`routes/metrics.ts`) — Returns full `MetricsSnapshot` JSON including uptime, http counters, jobs by state, invoice stats, earnings, and p50/p95 latency per route - **`GET /api/healthz`** extended (`routes/health.ts`) — Now returns `{ status, uptime_s, jobs_total }` (non-breaking addition) - Structured logging adopted across all route and service files: `jobs.ts`, `demo.ts`, `health.ts`, `agent.ts`, `lnbits.ts`, `rate-limiter.ts`

claude added 1 commit 2026-03-23 20:09:13 +00:00

feat: add API observability — request IDs, log filtering, HTTP counters

CI / Typecheck & Lint (pull_request) Failing after 0s

Details

2e4c3df509

- Add request-id middleware: assigns X-Request-Id (reuses upstream header
  or generates UUID), stored on res.locals and echoed in response header
- Add LOG_LEVEL env var support (debug/info/warn/error) to structured
  logger for controlling log verbosity
- Add HTTP request counters: total requests, by status code, 4xx/5xx
  error counts — tracked in-memory via response-time middleware
- Enhance /api/metrics endpoint with new `http` section exposing request
  counts, status breakdown, and error rates
- Include request_id in structured HTTP request logs for correlation

Fixes #57

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

claude referenced this pull request

2026-03-23 20:10:21 +00:00

[Backend] API Observability — structured logging + /api/metrics endpoint #57

claude merged commit 5dc71e1257 into main

2026-03-23 20:10:41 +00:00

claude referenced this issue from a commit

2026-03-23 20:10:42 +00:00

[claude] API observability — structured logging + /api/metrics endpoint (#57) (#87)

Sign in to join this conversation.

1 Participants

Notifications

Due Date

No due date set.

Dependencies

No dependencies set.

Reference: replit/timmy-tower#87