Microsoft Power Automate Retrieve a Flow Trigger Callback URL

arazzo: 1.0.1
info:
  title: Microsoft Power Automate Retrieve a Flow Trigger Callback URL
  summary: Confirm a flow is request-triggered, fetch its callback URL, and observe the resulting run.
  description: >-
    To invoke a Power Automate flow from an external system you need its
    callback URL, and that URL is only meaningful for a flow whose trigger is a
    request. This workflow reads the flow to confirm it is Started and carries a
    Request trigger, fetches the callback URL, and then observes the run history
    so the execution produced by calling that URL can be inspected. Note that
    the HTTP POST to the returned callback URL is deliberately not a step here:
    that endpoint is dynamically issued per flow and is not part of the
    management API this description references, so the caller performs it out of
    band between the fetch and the observation. 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: flowRunsApi
  url: ../openapi/microsoft-power-automate-flow-runs-api-openapi.yml
  type: openapi
- name: flowsApi
  url: ../openapi/microsoft-power-automate-flows-api-openapi.yml
  type: openapi
workflows:
- workflowId: flow-callback-url
  summary: Fetch a request-triggered flow's callback URL and observe the run it produces.
  description: >-
    Verifies the flow is active and request-triggered, retrieves the callback
    URL an external system uses to invoke it, and reads the run history and run
    detail so the invocation can be confirmed.
  inputs:
    type: object
    required:
    - environmentName
    - flowName
    properties:
      environmentName:
        type: string
        description: The name of the environment holding the flow.
      flowName:
        type: string
        description: The name or ID of the request-triggered flow.
  steps:
  - stepId: confirmRequestTrigger
    description: >-
      Read the flow and assert it is Started. The definition summary is captured
      so the caller can confirm the trigger is a Request kind before treating the
      callback URL as usable.
    operationId: getFlow
    parameters:
    - name: environmentName
      in: path
      value: $inputs.environmentName
    - name: flowName
      in: path
      value: $inputs.flowName
    successCriteria:
    - condition: $statusCode == 200
    - context: $response.body
      condition: $.properties.state == 'Started'
      type: jsonpath
    outputs:
      displayName: $response.body#/properties/displayName
      state: $response.body#/properties/state
      triggers: $response.body#/properties/definitionSummary/triggers
      flowTriggerUri: $response.body#/properties/flowTriggerUri
  - stepId: fetchCallbackUrl
    description: >-
      Retrieve the callback URL for the flow. This URL embeds its own signature
      and should be handled as a credential, since anyone holding it can invoke
      the flow.
    operationId: listCallbackUrl
    parameters:
    - name: environmentName
      in: path
      value: $inputs.environmentName
    - name: flowName
      in: path
      value: $inputs.flowName
    successCriteria:
    - condition: $statusCode == 200
    outputs:
      callbackUrl: $response.body#/response/value
  - stepId: observeRuns
    description: >-
      List the flow's run history after the caller has posted to the callback
      URL, so the invocation can be tied to a concrete run.
    operationId: listFlowRuns
    parameters:
    - name: environmentName
      in: path
      value: $inputs.environmentName
    - name: flowName
      in: path
      value: $inputs.flowName
    successCriteria:
    - condition: $statusCode == 200
    outputs:
      runs: $response.body#/value
      latestRunId: $response.body#/value/0/name
  - stepId: readLatestRun
    description: >-
      Read the most recent run in detail to confirm the callback invocation
      produced the expected execution and to surface its status and result code.
    operationId: getFlowRun
    parameters:
    - name: environmentName
      in: path
      value: $inputs.environmentName
    - name: flowName
      in: path
      value: $inputs.flowName
    - name: runId
      in: path
      value: $steps.observeRuns.outputs.latestRunId
    successCriteria:
    - condition: $statusCode == 200
    outputs:
      runStatus: $response.body#/properties/status
      resultCode: $response.body#/properties/code
      triggerName: $response.body#/properties/trigger/name
      startTime: $response.body#/properties/startTime
  outputs:
    callbackUrl: $steps.fetchCallbackUrl.outputs.callbackUrl
    flowDisplayName: $steps.confirmRequestTrigger.outputs.displayName
    latestRunId: $steps.observeRuns.outputs.latestRunId
    latestRunStatus: $steps.readLatestRun.outputs.runStatus