arazzo: 1.0.1
info:
  title: Prometheus Run a Large PromQL Expression via POST
  summary: Evaluate an expression too long for a URL, first instant then across a range.
  description: >-
    Long PromQL expressions — generated recording rules, wide label-matcher
    unions, or machine-composed queries — routinely exceed the URL length limits
    enforced by proxies and load balancers in front of Prometheus. Both query
    endpoints accept a form-encoded POST body for exactly this reason. The
    workflow validates the expression with an instant POST query and then
    evaluates it over a range with a range POST query. Every step spells out its
    request inline so the flow can be read and executed without opening the
    underlying OpenAPI description.
  version: 1.0.0
sourceDescriptions:
- name: httpApi
  url: ../openapi/prometheus-http-api-openapi.yml
  type: openapi
workflows:
- workflowId: large-promql-query-post
  summary: Evaluate a long PromQL expression through the POST query endpoints.
  description: >-
    Identical semantics to the GET query endpoints, with the expression carried
    in an application/x-www-form-urlencoded body instead of the query string.
  inputs:
    type: object
    required:
    - query
    - start
    - end
    - step
    properties:
      query:
        type: string
        description: >-
          The PromQL expression to evaluate. Typically long enough that URL
          encoding it would breach a proxy's request-line limit.
      start:
        type: string
        description: Start of the range as a Unix timestamp or RFC3339 string.
      end:
        type: string
        description: End of the range as a Unix timestamp or RFC3339 string.
      step:
        type: string
        description: Resolution step width as a duration string (e.g. 1m).
  steps:
  - stepId: evaluateInstantViaPost
    description: >-
      Evaluate the expression at a single point in time, sending it in the
      request body so no URL length limit applies.
    operationId: queryInstantPost
    requestBody:
      contentType: application/x-www-form-urlencoded
      payload:
        query: $inputs.query
        time: $inputs.end
        timeout: 60s
    successCriteria:
    - condition: $statusCode == 200
    - condition: $response.body#/status == "success"
    outputs:
      resultType: $response.body#/data/resultType
      result: $response.body#/data/result
  - stepId: evaluateRangeViaPost
    description: >-
      Evaluate the same expression across the full time range, again through the
      request body, producing the matrix used for charting or export.
    operationId: queryRangePost
    requestBody:
      contentType: application/x-www-form-urlencoded
      payload:
        query: $inputs.query
        start: $inputs.start
        end: $inputs.end
        step: $inputs.step
        timeout: 120s
    successCriteria:
    - condition: $statusCode == 200
    - condition: $response.body#/status == "success"
    - condition: $response.body#/data/resultType == "matrix"
    outputs:
      resultType: $response.body#/data/resultType
      series: $response.body#/data/result
  outputs:
    instantResult: $steps.evaluateInstantViaPost.outputs.result
    rangeSeries: $steps.evaluateRangeViaPost.outputs.series