System

Metrics

Scrape Prometheus-compatible metrics from the Blnk server and worker processes.

GET/metrics

Returns OpenTelemetry metrics in Prometheus text format. Requires enable_observability to be true on each process you scrape. See Metrics reference for metric names, types, and attributes.

Blnk runs the server and worker as separate processes. Each registers its own GET /metrics endpoint on a different port. The path is the same, but the series differ - scrape both targets in Prometheus to capture API and async processing signals.

Endpoint	Process	Port setting	Default URL
`GET /metrics`	Server	`server.port`	`http://localhost:5001/metrics`
`GET /metrics`	Worker	`queue.monitoring_port`	`http://localhost:5004/metrics`

See Health check for the same server/worker split on GET /health.

Authentication

/metrics uses Authorization: Bearer <token>, not X-Blnk-Key. When metrics_bearer_token is set, or secure mode is on without a token configured, bearer authentication applies. See Metrics endpoint.

Authorizationstringheader

Bearer token when required. Format: Bearer <metrics-bearer-token>.

curl -X GET "http://localhost:5001/metrics" \
  -H "Authorization: Bearer <metrics-bearer-token>"

curl -X GET "http://localhost:5004/metrics" \
  -H "Authorization: Bearer <metrics-bearer-token>"

When authentication fails, responses use structured JSON errors. See API error codes for AUTH_METRICS_TOKEN_REQUIRED, AUTH_INVALID_BEARER_TOKEN, and AUTH_METRICS_DISABLED.

# HELP blnk_transaction_total Total transactions by final status and currency
# TYPE blnk_transaction_total counter
blnk_transaction_total{currency="USD",status="APPLIED"} 128

{
  "error": "metrics bearer token required",
  "error_detail": {
    "code": "AUTH_METRICS_TOKEN_REQUIRED",
    "message": "metrics bearer token required",
    "details": {}
  }
}

Metrics

Authentication

Header