HTTP API

The current stable HTTP API is reachable under /api/v1 on a Prometheus server. Any non-breaking additions will be added under that endpoint.

Format overview

The API response format is JSON. Every successful API request returns a 2xx status code.

Invalid requests that reach the API handlers return a JSON error object and one of the following HTTP response codes:

  • 400 Bad Request when parameters are missing or incorrect.
  • 422 Unprocessable Entity when an expression can't be executed (RFC4918).
  • 503 Service Unavailable when queries time out or abort.

Other non-2xx codes may be returned for errors occurring before the API endpoint is reached.

The JSON response envelope format is as follows:

{
  "status": "success" | "error",
  "data": <data>,

  // Only set if status is "error". The data field may still hold
  // additional data.
  "errorType": "<string>",
  "error": "<string>"
}

Input timestamps may be provided either in RFC3339 format or as a Unix timestamp in seconds, with optional decimal places for sub-second precision. Output timestamps are always represented as Unix timestamps in seconds.

Names of query parameters that may be repeated end with [].

<series_selector> placeholders refer to Prometheus time series selectors like http_requests_total or http_requests_total{method=~"^GET|POST$"} and need to be URL-encoded.

<duration> placeholders refer to Prometheus duration strings of the form [0-9]+[smhdwy]. For example, 5m refers to a duration of 5 minutes.

Expression queries

Query language expressions may be evaluated at a single instant or over a range of time. The sections below describe the API endpoints for each type of expression query.

Instant queries

The following endpoint evaluates an instant query at a single point in time:

GET /api/v1/query

URL query parameters:

  • query=<string>: Prometheus expression query string.
  • time=<rfc3339 | unix_timestamp>: Evaluation timestamp. Optional.

The current server time is used if the time parameter is omitted.

The data section of the query result has the following format:

{
  "resultType": "matrix" | "vector" | "scalar" | "string",
  "result": <value>
}

<value> refers to the query result data, which has varying formats depending on the resultType. See the expression query result formats.

The following example evaluates the expression up at the time 2015-07-01T20:10:51.781Z:

$ curl 'http://localhost:9090/api/v1/query?query=up&time=2015-07-01T20:10:51.781Z'
{
   "status" : "success",
   "data" : {
      "resultType" : "vector",
      "result" : [
         {
            "metric" : {
               "__name__" : "up",
               "job" : "prometheus",
               "instance" : "localhost:9090"
            },
            "value": [ 1435781451.781, "1" ]
         },
         {
            "metric" : {
               "__name__" : "up",
               "job" : "node",
               "instance" : "localhost:9100"
            },
            "value" : [ 1435781451.781, "0" ]
         }
      ]
   }
}

Range queries

The following endpoint evaluates an expression query over a range of time:

GET /api/v1/query_range

URL query parameters:

  • query=<string>: Prometheus expression query string.
  • start=<rfc3339 | unix_timestamp>: Start timestamp.
  • end=<rfc3339 | unix_timestamp>: End timestamp.
  • step=<duration>: Query resolution step width.

The data section of the query result has the following format:

{
  "resultType": "matrix",
  "result": <value>
}

For the format of the <value> placeholder, see the range-vector result format.

The following example evaluates the expression up over a 30-second range with a query resolution of 15 seconds.

$ curl 'http://localhost:9090/api/v1/query_range?query=up&start=2015-07-01T20:10:30.781Z&end=2015-07-01T20:11:00.781Z&step=15s'
{
   "status" : "success",
   "data" : {
      "resultType" : "matrix",
      "result" : [
         {
            "metric" : {
               "__name__" : "up",
               "job" : "prometheus",
               "instance" : "localhost:9090"
            },
            "values" : [
               [ 1435781430.781, "1" ],
               [ 1435781445.781, "1" ],
               [ 1435781460.781, "1" ]
            ]
         },
         {
            "metric" : {
               "__name__" : "up",
               "job" : "node",
               "instance" : "localhost:9091"
            },
            "values" : [
               [ 1435781430.781, "0" ],
               [ 1435781445.781, "0" ],
               [ 1435781460.781, "1" ]
            ]
         }
      ]
   }
}

Querying metadata

Finding series by label matchers

The following endpoint returns the list of time series that match a certain label set.

GET /api/v1/series

URL query parameters:

  • match[]=<series_selector>: Repeated series selector argument that selects the series to return. At least one match[] argument must be provided.

The data section of the query result consists of a list of objects that contain the label name/value pairs which identify each series.

The following example returns all series that match either of the selectors up or process_start_time_seconds{job="prometheus"}:

$ curl -g 'http://localhost:9090/api/v1/series?match[]=up&match[]=process_start_time_seconds{job="prometheus"}'
{
   "status" : "success",
   "data" : [
      {
         "__name__" : "up",
         "job" : "prometheus",
         "instance" : "localhost:9090"
      },
      {
         "__name__" : "up",
         "job" : "node",
         "instance" : "localhost:9091"
      },
      {
         "__name__" : "process_start_time_seconds",
         "job" : "prometheus",
         "instance" : "localhost:9090"
      }
   ]
}

Querying label values

The following endpoint returns a list of label values for a provided label name:

GET /api/v1/label/<label_name>/values

The data section of the JSON response is a list of string label names.

This example queries for all label values for the job label:

$ curl http://localhost:9090/api/v1/label/job/values
{
   "status" : "success",
   "data" : [
      "node",
      "prometheus"
   ]
}

Deleting series

The following endpoint deletes matched series entirely from a Prometheus server:

DELETE /api/v1/series

URL query parameters:

  • match[]=<series_selector>: Repeated label matcher argument that selects the series to delete. At least one match[] argument must be provided.

The data section of the JSON response has the following format:

{
  "numDeleted": <number of deleted series>
}

The following example deletes all series that match either of the selectors up or process_start_time_seconds{job="prometheus"}:

$ curl -XDELETE -g 'http://localhost:9090/api/v1/series?match[]=up&match[]=process_start_time_seconds{job="prometheus"}'
{
   "status" : "success",
   "data" : {
      "numDeleted" : 3
   }
}

Expression query result formats

Expression queries may return the following response values in the result property of the data section. <sample_value> placeholders are numeric sample values. JSON does not support special float values such as NaN, Inf, and -Inf, so sample values are transferred as quoted JSON strings rather than raw numbers.

Range vectors

Range vectors are returned as result type matrix. The corresponding result property has the following format:

[
  {
    "metric": { "<label_name>": "<label_value>", ... },
    "values": [ [ <unix_time>, "<sample_value>" ], ... ]
  },
  ...
]

Instant vectors

Instant vectors are returned as result type vector. The corresponding result property has the following format:

[
  {
    "metric": { "<label_name>": "<label_value>", ... },
    "value": [ <unix_time>, "<sample_value>" ]
  },
  ...
]

Scalars

Scalar results are returned as result type scalar. The corresponding result property has the following format:

[ <unix_time>, "<scalar_value>" ]

Strings

String results are returned as result type string. The corresponding result property has the following format:

[ <unix_time>, "<string_value>" ]