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

# Subscribe to inbox notifications over SSE.

> Opens a Server-Sent Events stream that emits one frame per batch of newly-available messages on the inbox. The connection stays open until the JWT expires, at which point the server closes it.

Two kinds of frames are emitted:

- **Data frames** (`data: {...}\n\n`) signal availability only, they do not include message content. Consumers should call the lease endpoint to retrieve messages. The JSON payload is described by the response schema below.
- **Heartbeat frames** (`: keep-alive\n\n`) are SSE comment lines sent when no notification has arrived within the heartbeat interval. They are ignored by EventSource clients and exist only to keep intermediaries from closing the connection as idle.



## OpenAPI

````yaml white-label/trigger-inbox-openapi.yaml get /trigger-inbox/v1/inboxes/{inbox_id}/events
openapi: 3.1.0
info:
  title: Trigger Inbox API
  description: >-
    Manage trigger inboxes and their messages — create, pause, resume, and
    delete inboxes; list, lease, and acknowledge messages.
  version: 1.0.0
  contact:
    url: https://docs.zapier.com
servers:
  - url: https://api.zapier.com
    description: Production
security:
  - OAuth: []
tags:
  - name: inbox
    description: Inbox API endpoints
  - name: message
    description: Message API endpoints
paths:
  /trigger-inbox/v1/inboxes/{inbox_id}/events:
    get:
      tags:
        - inbox
      summary: Subscribe to inbox notifications over SSE.
      description: >-
        Opens a Server-Sent Events stream that emits one frame per batch of
        newly-available messages on the inbox. The connection stays open until
        the JWT expires, at which point the server closes it.


        Two kinds of frames are emitted:


        - **Data frames** (`data: {...}\n\n`) signal availability only, they do
        not include message content. Consumers should call the lease endpoint to
        retrieve messages. The JSON payload is described by the response schema
        below.

        - **Heartbeat frames** (`: keep-alive\n\n`) are SSE comment lines sent
        when no notification has arrived within the heartbeat interval. They are
        ignored by EventSource clients and exist only to keep intermediaries
        from closing the connection as idle.
      operationId: getTriggerInboxEvents
      parameters:
        - name: inbox_id
          in: path
          required: true
          schema:
            type: string
            format: uuid
          description: The unique identifier of the inbox to subscribe to.
      responses:
        '200':
          description: >-
            SSE stream opened. The response body is an open-ended sequence of
            `text/event-stream` frames.
          content:
            text/event-stream:
              schema:
                type: object
                description: >-
                  JSON payload carried by each `data:` frame. Heartbeat frames
                  carry no payload.
                properties:
                  inbox_id:
                    type: string
                    format: uuid
                    description: The unique identifier of the inbox that has new messages.
                  count:
                    type: integer
                    minimum: 1
                    description: The number of notifications coalesced into this frame.
                required:
                  - inbox_id
                  - count
        '401':
          description: Missing or invalid JWT in the Authorization header.
        '404':
          description: No inbox with the given id is visible to the authenticated user.
        '503':
          description: >-
            The notification backend was not reachable in time. Clients should
            retry.
      security:
        - OAuth:
            - external
components:
  securitySchemes:
    OAuth:
      type: oauth2
      description: OAuth 2.0 authentication.
      flows:
        authorizationCode:
          authorizationUrl: https://zapier.com/oauth/authorize
          tokenUrl: https://zapier.com/oauth/token
          scopes:
            external: Scope that gives access to all Public APIs
        clientCredentials:
          tokenUrl: https://zapier.com/oauth/token
          scopes:
            external: Scope that gives access to all Public APIs

````