prometheus/docs/querying/api.md

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---
title: HTTP API
sort_rank: 7
---
# 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](http://tools.ietf.org/html/rfc4918#page-78)).
- `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](https://www.ietf.org/rfc/rfc3339.txt) 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](basics.md#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.
- `timeout=<duration>`: Evaluation timeout. Optional. Defaults to and
is capped by the value of the `-query.timeout` flag.
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](#expression-query-result-formats).
The following example evaluates the expression `up` at the time
`2015-07-01T20:10:51.781Z`:
```json
$ 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.
- `timeout=<duration>`: Evaluation timeout. Optional. Defaults to and
is capped by the value of the `-query.timeout` flag.
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](#range-vectors).
The following example evaluates the expression `up` over a 30-second range with
a query resolution of 15 seconds.
```json
$ 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.
- `start=<rfc3339 | unix_timestamp>`: Start timestamp.
- `end=<rfc3339 | unix_timestamp>`: End timestamp.
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"}`:
```json
$ 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:
```json
$ curl http://localhost:9090/api/v1/label/job/values
{
"status" : "success",
"data" : [
"node",
"prometheus"
]
}
```
## 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>" ]
```
## Targets
> This API is experimental as it is intended to be extended with targets
> dropped due to relabelling in the future.
The following endpoint returns an overview of the current state of the
Prometheus target discovery:
```
GET /api/v1/targets
```
Currently only the active targets are part of the response.
```json
$ curl http://localhost:9090/api/v1/targets
{
"status": "success", [3/11]
"data": {
"activeTargets": [
{
"discoveredLabels": {
"__address__": "127.0.0.1:9090",
"__metrics_path__": "/metrics",
"__scheme__": "http",
"job": "prometheus"
},
"labels": {
"instance": "127.0.0.1:9090",
"job": "prometheus"
},
"scrapeUrl": "http://127.0.0.1:9090/metrics",
"lastError": "",
"lastScrape": "2017-01-17T15:07:44.723715405+01:00",
"health": "up"
}
]
}
}
```
## Alertmanagers
> This API is experimental as it is intended to be extended with Alertmanagers
> dropped due to relabelling in the future.
The following endpoint returns an overview of the current state of the
Prometheus alertmanager discovery:
```
GET /api/v1/alertmanagers
```
Currently only the active Alertmanagers are part of the response.
```json
$ curl http://localhost:9090/api/v1/alertmanagers
{
"status": "success",
"data": {
"activeAlertmanagers": [
{
"url": "http://127.0.0.1:9090/api/v1/alerts"
}
]
}
}
```