Beam Realtime Endpoints (WebSocket)

asyncapi: '2.6.0'
id: 'urn:cloud:beam:realtime:websocket'
info:
  title: Beam Realtime Endpoints (WebSocket)
  version: '1.0.0'
  description: |
    AsyncAPI 2.6 description of Beam's **realtime endpoint** surface.

    Unlike the synchronous REST web endpoints, a Beam realtime app is deployed
    and, per the docs (https://docs.beam.cloud/v2/endpoint/realtime), "will be
    exposed as a public websocket endpoint." Clients connect with the native
    WebSocket API or the Beam JavaScript SDK `deployment.realtime()` helper.

    This is a genuine bidirectional WebSocket transport (wss), not Server-Sent
    Events. Messages are exchanged in both directions over the open connection:
    the client sends input payloads and the server streams output payloads
    produced by the deployed Python handler.

    Synchronous endpoints, task queues, and the control-plane Tasks API are
    modeled in the companion OpenAPI document at `openapi/beam-cloud-openapi.yml`.
  contact:
    name: API Evangelist
    email: kin@apievangelist.com
    url: https://apievangelist.com
  license:
    name: API documentation - Beam Terms of Service
    url: https://www.beam.cloud/terms
  x-transport-notes:
    transport: WebSocket
    protocol: wss
    direction: bidirectional (client and server)
    triggeredBy: 'WebSocket connect to wss://{deployment-id}.app.beam.cloud'
    isWebSocket: true
    source: https://docs.beam.cloud/v2/endpoint/realtime
defaultContentType: application/json
servers:
  realtime:
    url: '{deploymentId}.app.beam.cloud'
    protocol: wss
    description: |
      Public WebSocket host for a deployed Beam realtime endpoint. The
      deploymentId is the unique id of the deployed app.
    variables:
      deploymentId:
        description: Unique id of the deployed realtime endpoint.
        default: '1c0f0cbe-e0d1-49ae-a556-5daffe23eb4c'
    security:
      - bearerAuth: []
channels:
  /:
    description: |
      The realtime WebSocket channel. After the client opens the connection
      (authenticating with a Beam Bearer token), it may publish input messages
      and subscribe to output messages streamed back from the deployed handler.
    bindings:
      ws:
        bindingVersion: '0.1.0'
    publish:
      operationId: sendRealtimeInput
      summary: Send an input payload to the deployed realtime handler.
      message:
        $ref: '#/components/messages/RealtimeInput'
    subscribe:
      operationId: receiveRealtimeOutput
      summary: Receive output payloads streamed from the realtime handler.
      message:
        $ref: '#/components/messages/RealtimeOutput'
components:
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      bearerFormat: 'Beam API token'
      description: |
        Beam bearer token. Provide `Authorization: Bearer <TOKEN>` when opening
        the WebSocket connection.
  messages:
    RealtimeInput:
      name: RealtimeInput
      title: Realtime input message
      summary: A JSON payload sent from the client into the deployed handler.
      contentType: application/json
      payload:
        type: object
        additionalProperties: true
    RealtimeOutput:
      name: RealtimeOutput
      title: Realtime output message
      summary: A JSON payload streamed from the handler back to the client.
      contentType: application/json
      payload:
        type: object
        additionalProperties: true