Temporal Workflows API

openapi: 3.0.3
info:
  title: Temporal HTTP Cluster Workflows API
  description: The Temporal HTTP API is a first-party grpc-gateway that maps a REST/JSON subset of the Temporal WorkflowService (gRPC) onto HTTP paths under `/api/v1`. Temporal's primary and complete API surface is gRPC (WorkflowService and OperatorService, defined as protobuf in github.com/temporalio/api); this HTTP API exists for automation, CI/CD, and environments where gRPC is impractical, and it exposes only a subset of the gRPC methods. The worker task-polling and task-completion RPCs (PollWorkflowTaskQueue, PollActivityTaskQueue, RespondWorkflowTaskCompleted, PollNexusTaskQueue, and similar) are NOT exposed over HTTP and remain gRPC-only. On Temporal Cloud the HTTP API is served per namespace over HTTPS; self-hosted it is served by the frontend service when the HTTP port is enabled. Requests authenticate with a Bearer API key (or mTLS on self-hosted). The paths and verbs below are drawn from the google.api.http annotations on the WorkflowService proto and are modeled here, not exhaustively confirmed against a live namespace.
  version: '1.0'
  contact:
    name: Temporal Technologies
    url: https://temporal.io
  license:
    name: MIT
    url: https://github.com/temporalio/api/blob/master/LICENSE
servers:
- url: https://{namespace}.{account}.tmprl.cloud/api/v1
  description: Temporal Cloud (per-namespace HTTP API endpoint)
  variables:
    namespace:
      default: your-namespace
      description: Your Temporal Cloud namespace name.
    account:
      default: your-account
      description: Your Temporal Cloud account (short) ID.
- url: http://localhost:7243/api/v1
  description: Self-hosted frontend HTTP API (when the HTTP port is enabled)
security:
- bearerAuth: []
tags:
- name: Workflows
  description: Start, describe, list, count, and read the history of workflow executions.
paths:
  /namespaces/{namespace}/workflows/{workflow_id}:
    parameters:
    - $ref: '#/components/parameters/Namespace'
    - name: workflow_id
      in: path
      required: true
      description: The workflow ID to start (client-assigned).
      schema:
        type: string
    post:
      operationId: startWorkflowExecution
      tags:
      - Workflows
      summary: Start a workflow execution
      description: Starts a new workflow execution. Maps to the gRPC StartWorkflowExecution RPC. The request body carries the workflow type, task queue, input, and options.
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/StartWorkflowExecutionRequest'
      responses:
        '200':
          description: The started workflow execution's run ID.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/StartWorkflowExecutionResponse'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '429':
          $ref: '#/components/responses/ResourceExhausted'
  /namespaces/{namespace}/workflows/{execution.workflow_id}:
    parameters:
    - $ref: '#/components/parameters/Namespace'
    - name: execution.workflow_id
      in: path
      required: true
      description: The workflow ID of the execution to describe.
      schema:
        type: string
    get:
      operationId: describeWorkflowExecution
      tags:
      - Workflows
      summary: Describe a workflow execution
      description: Returns information about the specified workflow execution - its status, type, task queue, timestamps, pending activities, and more. Maps to the gRPC DescribeWorkflowExecution RPC.
      parameters:
      - name: execution.run_id
        in: query
        required: false
        description: Optional run ID; defaults to the latest run.
        schema:
          type: string
      responses:
        '200':
          description: Details about the workflow execution.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/DescribeWorkflowExecutionResponse'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '404':
          $ref: '#/components/responses/NotFound'
  /namespaces/{namespace}/workflows:
    parameters:
    - $ref: '#/components/parameters/Namespace'
    get:
      operationId: listWorkflowExecutions
      tags:
      - Workflows
      summary: List workflow executions
      description: Lists workflow executions in a namespace, optionally filtered with a List Filter (SQL-like visibility query). Maps to the gRPC ListWorkflowExecutions RPC.
      parameters:
      - name: query
        in: query
        required: false
        description: A List Filter (visibility query) to filter executions.
        schema:
          type: string
      - name: page_size
        in: query
        required: false
        schema:
          type: integer
      - name: next_page_token
        in: query
        required: false
        schema:
          type: string
          format: byte
      responses:
        '200':
          description: A page of workflow executions.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ListWorkflowExecutionsResponse'
        '401':
          $ref: '#/components/responses/Unauthorized'
  /namespaces/{namespace}/workflow-count:
    parameters:
    - $ref: '#/components/parameters/Namespace'
    get:
      operationId: countWorkflowExecutions
      tags:
      - Workflows
      summary: Count workflow executions
      description: Returns the number of workflow executions matching a visibility query. Maps to the gRPC CountWorkflowExecutions RPC.
      parameters:
      - name: query
        in: query
        required: false
        schema:
          type: string
      responses:
        '200':
          description: The matching execution count.
          content:
            application/json:
              schema:
                type: object
                properties:
                  count:
                    type: string
                    format: int64
        '401':
          $ref: '#/components/responses/Unauthorized'
  /namespaces/{namespace}/archived-workflows:
    parameters:
    - $ref: '#/components/parameters/Namespace'
    get:
      operationId: listArchivedWorkflowExecutions
      tags:
      - Workflows
      summary: List archived workflow executions
      description: Lists workflow executions that have been archived. Maps to the gRPC ListArchivedWorkflowExecutions RPC.
      parameters:
      - name: query
        in: query
        required: false
        schema:
          type: string
      - name: page_size
        in: query
        required: false
        schema:
          type: integer
      - name: next_page_token
        in: query
        required: false
        schema:
          type: string
          format: byte
      responses:
        '200':
          description: A page of archived workflow executions.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ListWorkflowExecutionsResponse'
        '401':
          $ref: '#/components/responses/Unauthorized'
  /namespaces/{namespace}/workflows/{execution.workflow_id}/history:
    parameters:
    - $ref: '#/components/parameters/Namespace'
    - $ref: '#/components/parameters/ExecutionWorkflowId'
    get:
      operationId: getWorkflowExecutionHistory
      tags:
      - Workflows
      summary: Get workflow execution history
      description: Returns the event history of a workflow execution. Maps to the gRPC GetWorkflowExecutionHistory RPC.
      parameters:
      - name: execution.run_id
        in: query
        required: false
        schema:
          type: string
      - name: next_page_token
        in: query
        required: false
        schema:
          type: string
          format: byte
      responses:
        '200':
          description: The workflow event history.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/GetWorkflowExecutionHistoryResponse'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '404':
          $ref: '#/components/responses/NotFound'
  /namespaces/{namespace}/workflows/{execution.workflow_id}/history-reverse:
    parameters:
    - $ref: '#/components/parameters/Namespace'
    - $ref: '#/components/parameters/ExecutionWorkflowId'
    get:
      operationId: getWorkflowExecutionHistoryReverse
      tags:
      - Workflows
      summary: Get workflow execution history (reverse)
      description: Returns the event history of a workflow execution in reverse order. Maps to the gRPC GetWorkflowExecutionHistoryReverse RPC.
      parameters:
      - name: execution.run_id
        in: query
        required: false
        schema:
          type: string
      - name: next_page_token
        in: query
        required: false
        schema:
          type: string
          format: byte
      responses:
        '200':
          description: The workflow event history in reverse order.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/GetWorkflowExecutionHistoryResponse'
        '401':
          $ref: '#/components/responses/Unauthorized'
components:
  schemas:
    DescribeWorkflowExecutionResponse:
      type: object
      additionalProperties: true
      properties:
        workflowExecutionInfo:
          type: object
          additionalProperties: true
        pendingActivities:
          type: array
          items:
            type: object
            additionalProperties: true
    WorkflowType:
      type: object
      properties:
        name:
          type: string
    StartWorkflowExecutionRequest:
      type: object
      properties:
        namespace:
          type: string
        workflowId:
          type: string
        workflowType:
          $ref: '#/components/schemas/WorkflowType'
        taskQueue:
          $ref: '#/components/schemas/TaskQueue'
        input:
          $ref: '#/components/schemas/Payloads'
        requestId:
          type: string
        workflowIdReusePolicy:
          type: string
        workflowExecutionTimeout:
          type: string
        workflowRunTimeout:
          type: string
        workflowTaskTimeout:
          type: string
    Status:
      type: object
      description: A google.rpc.Status-style error payload.
      properties:
        code:
          type: integer
        message:
          type: string
        details:
          type: array
          items:
            type: object
            additionalProperties: true
    GetWorkflowExecutionHistoryResponse:
      type: object
      properties:
        history:
          type: object
          properties:
            events:
              type: array
              items:
                type: object
                additionalProperties: true
        nextPageToken:
          type: string
          format: byte
        archived:
          type: boolean
    StartWorkflowExecutionResponse:
      type: object
      properties:
        runId:
          type: string
    TaskQueue:
      type: object
      properties:
        name:
          type: string
        kind:
          type: string
    ListWorkflowExecutionsResponse:
      type: object
      properties:
        executions:
          type: array
          items:
            type: object
            additionalProperties: true
        nextPageToken:
          type: string
          format: byte
    Payloads:
      type: object
      description: Temporal payloads envelope. Each payload carries base64-encoded metadata and data.
      properties:
        payloads:
          type: array
          items:
            type: object
            properties:
              metadata:
                type: object
                additionalProperties:
                  type: string
                  format: byte
              data:
                type: string
                format: byte
  responses:
    NotFound:
      description: The requested workflow execution or namespace was not found.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Status'
    Unauthorized:
      description: Missing or invalid API key.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Status'
    ResourceExhausted:
      description: The namespace rate limit (APS/RPS/OPS) was exceeded. gRPC returns a ResourceExhausted status; over HTTP this surfaces as 429. Clients should back off and retry.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Status'
  parameters:
    ExecutionWorkflowId:
      name: execution.workflow_id
      in: path
      required: true
      description: The workflow ID of the target execution.
      schema:
        type: string
    Namespace:
      name: namespace
      in: path
      required: true
      description: The Temporal namespace.
      schema:
        type: string
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      description: 'Bearer API key. On Temporal Cloud, pass an API key as `Authorization: Bearer <api-key>`. Self-hosted deployments may use mTLS instead. Requests are scoped to the namespace in the path.'