Sinch Events API

openapi: 3.2.0
info:
  title: Sinch Conversation Events API
  description: The Sinch Conversation API is an omnichannel messaging platform that enables developers to send and receive messages across multiple channels including SMS, RCS, WhatsApp, Facebook Messenger, Instagram, Viber, Telegram, KakaoTalk, and LINE through a single unified API. It provides contact management, conversation tracking, message templating, and webhook callbacks for real-time event handling. The API normalizes message formats across channels, allowing developers to build multichannel messaging experiences without channel-specific integrations.
  version: '1.0'
  contact:
    name: Sinch Support
    url: https://www.sinch.com/contact-us/
  termsOfService: https://www.sinch.com/terms-of-service/
servers:
- url: https://us.conversation.api.sinch.com
  description: US Production Server
- url: https://eu.conversation.api.sinch.com
  description: EU Production Server
- url: https://br.conversation.api.sinch.com
  description: Brazil Production Server
security:
- oAuth2: []
- basicAuth: []
tags:
- name: Events
  description: Send and receive events such as composing indicators across supported channels.
paths:
  /v1/projects/{project_id}/events:send:
    post:
      operationId: sendEvent
      summary: Send an Event
      description: Sends an event such as a composing indicator to a contact on a specific channel.
      tags:
      - Events
      parameters:
      - $ref: '#/components/parameters/ProjectId'
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/SendEventRequest'
      responses:
        '200':
          description: Event sent
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/SendEventResponse'
        '400':
          description: Invalid request
        '401':
          description: Unauthorized
components:
  schemas:
    SendEventResponse:
      type: object
      properties:
        event_id:
          type: string
          description: The unique event identifier
        accepted_time:
          type: string
          format: date-time
          description: When the event was accepted
    SendEventRequest:
      type: object
      required:
      - app_id
      - recipient
      - event
      properties:
        app_id:
          type: string
          description: The app ID
        recipient:
          type: object
          description: The event recipient
          properties:
            contact_id:
              type: string
              description: The contact ID
        event:
          type: object
          description: The event to send
          properties:
            composing_event:
              type: object
              description: Composing indicator event
  parameters:
    ProjectId:
      name: project_id
      in: path
      required: true
      description: The unique project identifier
      schema:
        type: string
  securitySchemes:
    oAuth2:
      type: oauth2
      description: OAuth 2.0 client credentials flow using project key ID and secret.
      flows:
        clientCredentials:
          tokenUrl: https://auth.sinch.com/oauth2/token
          scopes: {}
    basicAuth:
      type: http
      scheme: basic
      description: Key ID as username and key secret as password.
externalDocs:
  description: Sinch Conversation API Documentation
  url: https://developers.sinch.com/docs/conversation