Agent-Skills.md

Agent Skills: Observability Standards

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. (triggers: main.ts, **/*.module.ts, nestjs-pino, Prometheus, Logger, reqId)

UncategorizedID: hoangnguyen0403/agent-skills-standard/nestjs-observability

Repository

hoangnguyen0403/agent-skills-standard
HoangNguyen0403License: Apache-2.0
362103

Install this agent skill to your local

pnpm dlx add-skill https://github.com/HoangNguyen0403/agent-skills-standard/tree/HEAD/skills/nestjs/nestjs-observability

Skill Files

Browse the full folder contents for nestjs-observability.

Download Skill

Loading file tree…

skills/nestjs/nestjs-observability/SKILL.md

Skill Metadata

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. (triggers: main.ts, **/*.module.ts, nestjs-pino, Prometheus, Logger, reqId)"

Observability Standards

Priority: P1 (OPERATIONAL)

Logging, monitoring, and observability patterns for production NestJS applications.

Structured Logging (Pino)

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

See implementation examples

Tracing (Correlation)

  • Request ID: Every log line must include a 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.

Performance Headers (Dev Only)

  • X-Response-Duration-Ms, X-DB-Execution-Ms, X-API-Overhead-Ms
  • Gate behind ENABLE_PERFORMANCE_BENCHMARK feature flag; never expose in production.

Anti-Patterns

  • No console.log: Use nestjs-pino for async, structured, JSON-formatted logging.
  • No missing reqId: Propagate x-request-id header to all downstream services and queries.
  • No perf data in production by default: Gate benchmarking behind ENABLE_PERFORMANCE_BENCHMARK flag.