nestjs-observability

name	nestjs-observability
description	Configure structured logging with Pino, Prometheus metrics, and health checks for NestJS services. Use when adding JSON logging, request tracing with correlation IDs, Prometheus metric endpoints, or liveness/readiness health checks.
metadata	{"triggers":{"files":["main.ts","**/*.module.ts"],"keywords":["nestjs-pino","Prometheus","Logger","reqId"]}}

Observability Standards

Priority: P1 (HIGH)

Structured Logging (Pino)

Use nestjs-pino for high-performance, async JSON logging. Node's console.log blocking and unstructured.

See implementation examples

Tracing (Correlation)

• Request ID: Every log line must include reqId. nestjs-pino handles this via AsyncLocalStorage.
• Propagation: Pass x-request-id to downstream microservices and database queries for end-to-end tracing.

Metrics

Expose /metrics for Prometheus scraping using @willsoto/nestjs-prometheus.

See implementation examples

Health Checks

• Terminus: Implement "Liveness" (I'm alive) vs "Readiness" (I can take traffic).
• DB Check: TypeOrmHealthIndicator / PrismaHealthIndicator.
• Memory Check: Fail readiness if Heap > 300MB to prevent crash loops.