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

# Request on-demand message history

> Triggers an on-demand history sync request for the given chat. The response arrives
asynchronously as a `message_history_sync` event via the configured publisher.




## OpenAPI

````yaml /openapi/wsapi-api.yaml post /chats/{chatId}/messages
openapi: 3.0.3
info:
  title: WSAPI - WhatsApp API
  description: >-
    RESTful HTTP API for WhatsApp via whatsmeow. Supports multi-instance
    connections, connections, webhook event delivery, and HMAC-SHA256 signing.
    Includes self-service instance management endpoints served by the API
    Gateway.
  version: 2.0.0
servers:
  - url: https://api.wsapi.chat
    description: WSAPI API
security:
  - ApiKeyAuth: []
tags:
  - name: Account
    description: >-
      Customer account management — instances, subscriptions, and default
      settings (CustomerApiKey auth)
  - name: Session
    description: WhatsApp session management (login, logout, status)
  - name: Messages
    description: Send and manage WhatsApp messages
  - name: Groups
    description: Group management
  - name: Communities
    description: Community management
  - name: Contacts
    description: Contact lookup and management
  - name: Users
    description: Own account management, user lookup, and profile information
  - name: Media
    description: Media download
  - name: Chats
    description: Chat listing, info, settings, and management
  - name: Calls
    description: Call management
  - name: Newsletters
    description: Newsletter/channel management
  - name: Status
    description: Status/stories posting
paths:
  /chats/{chatId}/messages:
    post:
      tags:
        - Chats
      summary: Request on-demand message history
      description: >
        Triggers an on-demand history sync request for the given chat. The
        response arrives

        asynchronously as a `message_history_sync` event via the configured
        publisher.
      operationId: requestChatMessages
      parameters:
        - $ref: '#/components/parameters/XInstanceId'
        - $ref: '#/components/parameters/ChatIdPath'
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/RequestMessagesRequest'
            example:
              lastMessageId: 3EB0A0B0C1D2E3F4
              lastMessageSenderId: '1234567890'
              count: 50
      responses:
        '202':
          description: History sync request accepted
          content:
            application/json:
              schema:
                type: object
                properties:
                  status:
                    type: string
                    example: ok
        '400':
          $ref: '#/components/responses/BadRequest'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '409':
          $ref: '#/components/responses/DeviceNotPaired'
        '503':
          $ref: '#/components/responses/ServiceUnavailable'
components:
  parameters:
    XInstanceId:
      name: X-Instance-Id
      in: header
      required: true
      description: The ID of the WhatsApp instance to use
      schema:
        type: string
        default: '{{instanceId}}'
    ChatIdPath:
      name: chatId
      in: path
      required: true
      description: Chat JID (user or group)
      schema:
        type: string
  schemas:
    RequestMessagesRequest:
      type: object
      required:
        - lastMessageId
        - lastMessageSenderId
      properties:
        lastMessageId:
          type: string
          description: ID of the last known message in the chat
        lastMessageSenderId:
          type: string
          description: Phone number or JID of the sender of the last known message
        count:
          type: integer
          description: Number of messages to request (default 50, max 500)
          minimum: 1
          maximum: 500
          default: 50
    Error:
      type: object
      description: Standard error response returned by all API endpoints
      required:
        - detail
        - status
      properties:
        detail:
          type: string
          description: Human-readable error message
          example: invalid request body
        status:
          type: integer
          description: HTTP status code
          example: 400
  responses:
    BadRequest:
      description: Bad request
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
          example:
            status: 400
            detail: invalid request body
    Unauthorized:
      description: Authentication failed
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
          example:
            status: 401
            detail: unauthorized
    DeviceNotPaired:
      description: Device is not paired. Complete the pairing process first.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
          example:
            status: 403
            detail: device not paired
    ServiceUnavailable:
      description: Instance not available (not connected or service is nil)
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
          example:
            status: 503
            detail: instance not available
  securitySchemes:
    ApiKeyAuth:
      type: apiKey
      in: header
      name: X-Api-Key
      description: >-
        Instance or customer-level API key. Either the instance's own API key or
        the customer's API key is accepted. Must be paired with the
        X-Instance-Id header to identify the target instance.

````