Cumulocity Real-Time Notifications API

openapi: 3.0.3
info:
  title: Cumulocity Real-Time Notifications API
  version: 10.20.0
  description: |
    Bayeux/CometD-based long-poll subscription protocol for receiving live updates of measurements, events,
    alarms, operations, and inventory changes. Predates Notification 2.0 but remains the default for the Web
    SDK and legacy integrations.
servers:
- url: https://{tenant}.cumulocity.com
  variables:
    tenant:
      default: example
security:
- basicAuth: []
- bearerAuth: []
tags:
- name: Bayeux Handshake
- name: Subscription
paths:
  /notification/realtime:
    post:
      tags: [Bayeux Handshake]
      summary: Bayeux Channel Endpoint (Handshake, Connect, Subscribe, Disconnect)
      operationId: bayeuxChannelEndpoint
      description: |
        Single endpoint for the Bayeux/CometD protocol. The channel of the message body determines the
        action — `/meta/handshake`, `/meta/connect`, `/meta/subscribe`, `/meta/unsubscribe`,
        `/meta/disconnect`. Subscribe to channels such as `/measurements/{deviceId}`,
        `/events/{deviceId}`, `/alarms/{deviceId}`, `/operations/{deviceId}`, `/managedobjects/{deviceId}`.
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/BayeuxMessage'
      responses:
        '200':
          description: Bayeux protocol response.
          content:
            application/json:
              schema:
                type: array
                items:
                  $ref: '#/components/schemas/BayeuxMessage'
components:
  securitySchemes:
    basicAuth:
      type: http
      scheme: basic
    bearerAuth:
      type: http
      scheme: bearer
      bearerFormat: JWT
  schemas:
    BayeuxMessage:
      type: object
      required: [channel]
      properties:
        channel: {type: string}
        clientId: {type: string}
        id: {type: string}
        data: {}
        successful: {type: boolean}
        subscription: {type: string}
        ext:
          type: object
        advice:
          type: object
        supportedConnectionTypes:
          type: array
          items: {type: string}
        connectionType: {type: string}
        version: {type: string}
        minimumVersion: {type: string}