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)

install

source · Clone the upstream repo

git clone https://github.com/ComeOnOliver/skillshub

Claude Code · Install into ~/.claude/skills/

T=$(mktemp -d) && git clone --depth=1 https://github.com/ComeOnOliver/skillshub "$T" && mkdir -p ~/.claude/skills && cp -r "$T/skills/HoangNguyen0403/agent-skills-standard/nestjs-observability" ~/.claude/skills/comeonoliver-skillshub-nestjs-observability && rm -rf "$T"

manifest: skills/HoangNguyen0403/agent-skills-standard/nestjs-observability/SKILL.md

source content

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:

```
http_request_duration_seconds
```
(Histogram)
```
db_query_duration_seconds
```
(Histogram)
```
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

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.