Contextual AI Agent Query Streaming (HTTP + SSE)

asyncapi: '2.6.0'
id: 'urn:ai:contextual:v1:agent-query:sse'
info:
  title: Contextual AI Agent Query Streaming (HTTP + SSE)
  version: '1.0.0'
  description: |
    AsyncAPI 2.6 description of Contextual AI's **agent query streaming**
    surface.

    Contextual AI does not publish a WebSocket API. The only asynchronous /
    event-style transport documented at
    https://docs.contextual.ai/api-reference/agents-query/query is **HTTP
    Server-Sent Events (SSE)** delivered over the same REST endpoint
    (`POST /agents/{agent_id}/query`) when the request body sets
    `stream: true`. SSE is a one-way, server-to-client HTTP streaming
    channel; it is **not** WebSocket.

    This AsyncAPI document models only the streamed events emitted by the
    SSE response (token deltas, attribution / retrieval events, and a final
    completion event). The request body itself (messages, stream, filters,
    overrides) is modeled in the companion OpenAPI document at
    `openapi/contextual-ai-openapi.yml`.

    The standalone Generate, Rerank, Parse, and LMUnit component APIs return
    single JSON HTTP responses and are **not** SSE-streamed; they are not
    modeled here.
  contact:
    name: API Evangelist
    email: kin@apievangelist.com
    url: https://apievangelist.com
  license:
    name: API documentation - Contextual AI Terms of Service
    url: https://contextual.ai/terms-of-service/
  x-transport-notes:
    transport: HTTP Server-Sent Events (SSE)
    protocol: https
    direction: server-to-client (one-way)
    mediaType: text/event-stream
    triggeredBy: 'POST https://api.contextual.ai/v1/agents/{agent_id}/query with request body { "stream": true }'
    notWebSocket: true
    source: https://docs.contextual.ai/api-reference/agents-query/query
defaultContentType: text/event-stream
servers:
  contextual:
    url: api.contextual.ai/v1
    protocol: https
    description: |
      Contextual AI's REST base. Agent query streaming is delivered as HTTP
      Server-Sent Events over this base when `stream: true` is set on the JSON
      request body. AsyncAPI 2.6 does not define a dedicated SSE protocol
      identifier; `https` is used here and the SSE transport is documented in
      `info.x-transport-notes` and on each channel.
    security:
      - bearerAuth: []
channels:
  /agents/{agent_id}/query:
    description: |
      Agent query SSE stream. The client opens this channel by issuing
      `POST /agents/{agent_id}/query` with `Content-Type: application/json`
      and a JSON body containing `stream: true`. The server responds with
      `Content-Type: text/event-stream` and emits a sequence of `data:` lines
      carrying grounded response token deltas, optional attribution and
      retrieval events, and a final completion event.
    parameters:
      agent_id:
        description: UUID of the agent being queried.
        schema:
          type: string
          format: uuid
    bindings:
      http:
        type: request
        method: POST
        bindingVersion: '0.3.0'
      x-sse:
        mediaType: text/event-stream
        eventField: 'data'
    subscribe:
      operationId: streamAgentQueryEvents
      summary: Subscribe to streamed agent query events (SSE).
      description: |
        After `POST /agents/{agent_id}/query` is issued with `stream: true`,
        the server emits an ordered sequence of SSE `data:` events carrying
        grounded response token deltas, attribution / retrieval events, and a
        terminal completion event.
      bindings:
        http:
          type: response
          bindingVersion: '0.3.0'
      message:
        oneOf:
          - $ref: '#/components/messages/MessageDelta'
          - $ref: '#/components/messages/AttributionEvent'
          - $ref: '#/components/messages/QueryComplete'
components:
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      bearerFormat: 'Contextual AI API key'
      description: |
        Standard Contextual AI bearer token. Set the
        `Authorization: Bearer <CONTEXTUAL_API_KEY>` header on the
        `POST /agents/{agent_id}/query` request that opens the SSE stream.
  messages:
    MessageDelta:
      name: MessageDelta
      title: Streamed grounded response delta
      summary: |
        A single SSE `data:` event carrying one delta of the grounded agent
        response. Many of these are emitted per request, in order.
      contentType: application/json
      payload:
        $ref: '#/components/schemas/MessageDelta'
      examples:
        - name: contentDelta
          summary: Token delta
          payload:
            type: message_delta
            content: 'The policy'
            conversation_id: 7c2f4b9a-2d3e-4a1b-9c8d-1e2f3a4b5c6d
            message_id: a1b2c3d4-5e6f-7a8b-9c0d-1e2f3a4b5c6d
    AttributionEvent:
      name: AttributionEvent
      title: Streamed attribution / retrieval event
      summary: |
        SSE event carrying inline attribution or retrieval-content metadata
        for the grounded response.
      contentType: application/json
      payload:
        $ref: '#/components/schemas/AttributionEvent'
      examples:
        - name: attribution
          summary: Attribution event
          payload:
            type: attribution
            content_id: f0e1d2c3-b4a5-6789-0a1b-2c3d4e5f6a7b
            groundedness_score: 0.97
    QueryComplete:
      name: QueryComplete
      title: Stream completion event
      summary: |
        Terminal SSE event marking the end of the grounded response stream,
        carrying the final message identifiers and groundedness scores.
      contentType: application/json
      payload:
        $ref: '#/components/schemas/QueryComplete'
      examples:
        - name: done
          summary: Completion event
          payload:
            type: message_complete
            conversation_id: 7c2f4b9a-2d3e-4a1b-9c8d-1e2f3a4b5c6d
            message_id: a1b2c3d4-5e6f-7a8b-9c0d-1e2f3a4b5c6d
  schemas:
    MessageDelta:
      type: object
      description: A delta of the grounded agent response streamed as an SSE event.
      required:
        - type
        - content
      properties:
        type:
          type: string
          enum:
            - message_delta
          description: The event type for a token delta.
        content:
          type: string
          description: Token slice of the grounded response.
        conversation_id:
          type: string
          format: uuid
          description: Identifier for continuing the conversation.
        message_id:
          type: string
          format: uuid
          description: Identifier for this assistant message.
    AttributionEvent:
      type: object
      description: An attribution / retrieval metadata event for the grounded response.
      required:
        - type
      properties:
        type:
          type: string
          enum:
            - attribution
            - retrieval
          description: The event type.
        content_id:
          type: string
          format: uuid
          description: Identifier of the retrieved content the claim is attributed to.
        groundedness_score:
          type: number
          format: double
          description: Confidence that the associated claim is grounded in the source.
    QueryComplete:
      type: object
      description: Terminal completion event for the agent query SSE stream.
      required:
        - type
      properties:
        type:
          type: string
          enum:
            - message_complete
          description: Marks the end of the stream.
        conversation_id:
          type: string
          format: uuid
        message_id:
          type: string
          format: uuid
        groundedness_scores:
          type: array
          items:
            type: number
            format: double
          description: Per-claim groundedness scores for the full response.