openapi: 3.1.0
info:
  title: Booking.com Car Rentals Accommodations Messages API
  description: The Booking.com Car Rentals API is part of the Demand API and provides endpoints specific to the car rental segment of the connected trip experience. Developers can use it to search for available car rentals, retrieve car details, look up depots and suppliers, and access depot review scores. The API enables affiliate partners to integrate Booking.com's car rental inventory into their own platforms, offering users the ability to find and book vehicles as part of their travel planning workflow.
  version: '3.1'
  contact:
    name: Booking.com Developer Support
    url: https://developers.booking.com/demand/docs
  termsOfService: https://www.booking.com/content/terms.html
servers:
- url: https://demandapi.booking.com/3.1
  description: Production Server
security:
- bearerAuth: []
  affiliateId: []
tags:
- name: Messages
  description: Endpoints for two-way post-booking communication between guests and properties, allowing you to send and retrieve messages, exchange images, and check conversation details.
paths:
  /messages/send:
    post:
      operationId: sendMessage
      summary: Send a message
      description: Sends a message within a conversation. The message body supports plain text and optionally allows attaching a file by referencing a previously uploaded attachment ID.
      tags:
      - Messages
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/SendMessageRequest'
      responses:
        '200':
          description: Message sent successfully
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/SendMessageResponse'
        '400':
          description: Bad request
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
        '401':
          description: Unauthorized
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
  /messages/latest:
    post:
      operationId: fetchLatestMessages
      summary: Fetch latest messages
      description: Retrieves up to 100 of the most recent messages from a specified conversation, including messages from both property and guest, returned in reverse chronological order (newest first). Can be used to sync message threads or poll for updates.
      tags:
      - Messages
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/FetchMessagesRequest'
      responses:
        '200':
          description: Messages retrieved successfully
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/FetchMessagesResponse'
        '400':
          description: Bad request
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
        '401':
          description: Unauthorized
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
  /messages/latest/confirm:
    post:
      operationId: confirmMessages
      summary: Confirm message receipt
      description: Confirms receipt of specified messages. This confirmation is required before receiving new messages from the POST /messages/latest endpoint.
      tags:
      - Messages
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/ConfirmMessagesRequest'
      responses:
        '200':
          description: Messages confirmed successfully
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ConfirmMessagesResponse'
        '400':
          description: Bad request
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
        '401':
          description: Unauthorized
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
components:
  schemas:
    SendMessageResponse:
      type: object
      properties:
        result:
          type: object
          properties:
            message_id:
              type: string
              description: Unique identifier of the sent message
            status:
              type: string
              description: Message delivery status
    SendMessageRequest:
      type: object
      required:
      - conversation_id
      - message
      properties:
        conversation_id:
          type: string
          description: Identifier of the conversation to send the message in
        message:
          type: string
          description: Plain text message body
        attachment_id:
          type: string
          description: ID of a previously uploaded attachment to include
    ConfirmMessagesRequest:
      type: object
      required:
      - conversation_id
      - message_ids
      properties:
        conversation_id:
          type: string
          description: Identifier of the conversation
        message_ids:
          type: array
          description: IDs of messages to confirm receipt of
          items:
            type: string
    ConfirmMessagesResponse:
      type: object
      properties:
        result:
          type: object
          properties:
            confirmed:
              type: boolean
              description: Whether confirmation was successful
    FetchMessagesResponse:
      type: object
      properties:
        result:
          type: array
          description: List of messages in reverse chronological order
          items:
            $ref: '#/components/schemas/Message'
    ErrorResponse:
      type: object
      description: Standard error response
      properties:
        errors:
          type: array
          description: List of errors
          items:
            type: object
            properties:
              code:
                type: string
                description: Error code
              message:
                type: string
                description: Human-readable error message
    Message:
      type: object
      description: A message in a conversation
      properties:
        message_id:
          type: string
          description: Unique message identifier
        conversation_id:
          type: string
          description: Conversation this message belongs to
        sender:
          type: string
          description: Who sent the message
          enum:
          - guest
          - property
        body:
          type: string
          description: Message text content
        attachment:
          type: object
          description: Optional attachment
          properties:
            attachment_id:
              type: string
              description: Attachment identifier
            url:
              type: string
              format: uri
              description: Attachment URL
        created_at:
          type: string
          format: date-time
          description: Message creation timestamp
    FetchMessagesRequest:
      type: object
      required:
      - conversation_id
      properties:
        conversation_id:
          type: string
          description: Identifier of the conversation to fetch messages from
        limit:
          type: integer
          description: Maximum number of messages to retrieve
          maximum: 100
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      description: Bearer token authentication. Include your API key token in the Authorization header.
    affiliateId:
      type: apiKey
      in: header
      name: X-Affiliate-Id
      description: Your Booking.com Affiliate ID, required with every request.
externalDocs:
  description: Booking.com Car Rentals API Documentation
  url: https://developers.booking.com/demand/docs/open-api/demand-api/cars