>_SkillsHub▋

> nestjs-observability

Structured logging (Pino) and Prometheus metrics. Use when adding structured logging with Pino or Prometheus metrics to NestJS services. (triggers: main.ts, **/*.module.ts, nestjs-pino, Prometheus, Logger, reqId)

fetch
$curl "https://skillshub.wtf/HoangNguyen0403/agent-skills-standard/nestjs-observability?format=md"
SKILL.md•nestjs-observability

Observability Standards

Priority: P1 (OPERATIONAL)

Logging, monitoring, and observability patterns for production applications.

  • Standard: Use nestjs-pino for high-performance JSON logging.
    • Why: Node's built-in console.log is blocking and unstructured.
  • Configuration:
    • Redaction: Mandatory masking of sensitive fields (password, token, email).
    • Context: Always inject Logger and set the context (LoginService).

Tracing (Correlation)

  • Request ID: Every log line must include a reqId (Request ID).
    • nestjs-pino handles this automatically using AsyncLocalStorage.
    • Propagation: Pass x-request-id to downstream microservices/database queries key to trace flows.

API Overhead & Database Benchmarking

  • Execution Bucket Strategy: When performance profiling is enabled, utilize global interceptors combined with AsyncLocalStorage to split and expose latency into logical buckets.
  • Headers: Expose the metrics via HTTP Headers on the response for immediate feedback during development or testing:
    • X-Response-Duration-Ms (Total execution time)
    • X-DB-Execution-Ms (Time spent exclusively in database queries, tracked via TypeORM loggers)
    • X-API-Overhead-Ms (Time spent in NestJS interceptors, guards, and serialization)
  • Security: Only enable performance headers and detailed SQL benchmarking in development or when a specific feature flag (ENABLE_PERFORMANCE_BENCHMARK) is explicitly active.

Metrics

  • Exposure: Use @willsoto/nestjs-prometheus to expose /metrics for Prometheus scraping.
  • Key Metrics:
    1. http_request_duration_seconds (Histogram)
    2. db_query_duration_seconds (Histogram)
    3. memory_usage_bytes (Gauge)

Health Checks

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

🚫 Anti-Patterns

  • Do NOT use standard patterns if specific project rules exist.
  • Do NOT ignore error handling or edge cases.

> related_skills --same-repo

> typescript-tooling

Development tools, linting, and build config for TypeScript. Use when configuring ESLint, Prettier, Jest, Vitest, tsconfig, or any TS build tooling. (triggers: tsconfig.json, .eslintrc.*, jest.config.*, package.json, eslint, prettier, jest, vitest, build, compile, lint)

> typescript-security

Secure coding practices for TypeScript. Use when validating input, handling auth tokens, sanitizing data, or managing secrets and sensitive configuration. (triggers: **/*.ts, **/*.tsx, validate, sanitize, xss, injection, auth, password, secret, token)

> typescript-language

Modern TypeScript standards for type safety and maintainability. Use when working with types, interfaces, generics, enums, unions, or tsconfig settings. (triggers: **/*.ts, **/*.tsx, tsconfig.json, type, interface, generic, enum, union, intersection, readonly, const, namespace)

> typescript-best-practices

Idiomatic TypeScript patterns for clean, maintainable code. Use when writing or refactoring TypeScript classes, functions, modules, or async logic. (triggers: **/*.ts, **/*.tsx, class, function, module, import, export, async, promise)

┌ stats

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github stars341
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first seenMar 17, 2026
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┌ repo

HoangNguyen0403/agent-skills-standard
by HoangNguyen0403
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┌ tags

#monitoring
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