GET /metrics

The metric registry, in the Prometheus text exposition format.

GET /metrics

Answered from the moment the socket is bound — a process that is still loading is exactly what an operator wants numbers about — and never rate limited, because throttling a scraper blinds the only thing that could see the throttling. It is not a probe: where the deployment requires a bearer token to be asked a question, it requires one to be measured.

Authentication

Accepted: bearerAuth (http bearer), or no credentials.

Parameters

Parameter
X-Request-Id	A correlation id to answer under. A value the server cannot log safely — too long, or carrying anything outside its id alphabet — is discarded and a fresh id minted, because a log line is read by a human and must not be forgeable by a header. (in header)

Responses

200

The registry as a Prometheus scraper reads it.

text/plain — PrometheusExposition

Response header
X-Request-Id	The correlation id this request was answered under. It is on every response, in the server’s log record for the request, and inside the error object of every refusal.

401

unauthorized — no bearer token was presented, or the one presented is not a credential this deployment accepts. A request with no token is answered only where the deployment configuration says anonymous access is allowed

application/json — Error

Response header
WWW-Authenticate	The challenge, naming the one scheme this server accepts.
X-Request-Id	The correlation id this request was answered under. It is on every response, in the server’s log record for the request, and inside the error object of every refusal.