> ## Documentation Index
> Fetch the complete documentation index at: https://docs.tryblend.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Stream a run

> Opens an SSE stream for an existing run.

Use it to resume a dropped `POST /responses` stream or attach to a run started with `stream: false`. First event is always `response.resumed`.



## OpenAPI

````yaml /openapi.json get /api/v1/runs/{runId}/stream
openapi: 3.0.3
info:
  title: Blend AI Workflow API
  version: 1.0.0
  description: Run published Blend AI workflows over HTTP.
  contact:
    name: Blend AI Support
    url: https://tryblend.ai
servers:
  - url: https://tryblend.ai
    description: Production
security:
  - BearerAuth: []
paths:
  /api/v1/runs/{runId}/stream:
    get:
      summary: Stream a run
      description: >-
        Opens an SSE stream for an existing run.


        Use it to resume a dropped `POST /responses` stream or attach to a run
        started with `stream: false`. First event is always `response.resumed`.
      operationId: streamRun
      parameters:
        - name: runId
          in: path
          required: true
          schema:
            type: string
          description: Run ID to attach to.
      responses:
        '200':
          description: Server-Sent Events stream.
          content:
            text/event-stream:
              schema:
                type: string
        '401':
          $ref: '#/components/responses/Unauthorized'
        '404':
          $ref: '#/components/responses/NotFound'
        '429':
          $ref: '#/components/responses/RateLimited'
        '500':
          $ref: '#/components/responses/ServerError'
components:
  responses:
    Unauthorized:
      description: Missing or invalid API key.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorEnvelope'
    NotFound:
      description: >-
        Run, published workflow, or version not found — or not owned by the
        caller.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorEnvelope'
    RateLimited:
      description: >-
        Per-API-key rate limit exceeded. Inspect `X-RateLimit-*` and
        `Retry-After` headers.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorEnvelope'
    ServerError:
      description: Unexpected server error.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorEnvelope'
  schemas:
    ErrorEnvelope:
      type: object
      required:
        - error
      properties:
        error:
          type: object
          required:
            - message
            - type
          properties:
            message:
              type: string
              example: Invalid or missing API key.
            type:
              type: string
              enum:
                - authentication_error
                - insufficient_credits
                - rate_limit_error
                - invalid_request_error
                - not_found_error
                - server_error
            code:
              type: string
              description: >-
                Machine-readable sub-code. Examples: `invalid_api_key`,
                `rate_limit_exceeded`, `insufficient_credits`, `not_found`,
                `published_workflow_not_found`,
                `published_workflow_version_not_found`, `invalid_input_fields`,
                `workflow_graph_corrupt`.
  securitySchemes:
    BearerAuth:
      type: http
      scheme: bearer
      bearerFormat: bai_...
      description: >-
        API key issued from the Blend AI dashboard. Prefix: `bai_`. Send as
        `Authorization: Bearer bai_...`.

````