> ## Documentation Index > Fetch the complete documentation index at: https://developer.meetergo.com/llms.txt > Use this file to discover all available pages before exploring further. # Send a WhatsApp message > Sends a text, template, or media message addressed by phone number. The conversation is created or reused automatically. Free-form text and media require an open 24-hour customer-service window (since the contact last messaged you); approved templates can be sent anytime. Outside the window, text/media return 403 — send a template to re-engage. ## OpenAPI ````yaml /openapi.json post /v4/whatsapp/messages openapi: 3.0.0 info: title: meetergo Platform API description: >- Scheduling, CRM and invoicing in one API: create users, manage availability and bookings, connect calendars, keep contacts and deals in sync, and take an offer through to a paid invoice. version: 3.274.0 contact: {} termsOfService: https://www.meetergo.com/tos/ servers: [] security: [] tags: - name: User V4 description: Create and manage users in your workspace - name: Meeting Type V4 description: Configure meeting templates with durations, buffers, and conferencing - name: availability description: Manage weekly schedules and availability settings - name: Booking V4 description: Create new bookings - name: Booking Availability V4 description: Query available time slots for booking - name: Appointment V4 description: Manage existing appointments - name: Attendee V4 description: Manage attendee details and notes - name: Calendar Connections V4 description: Connect and sync external calendars - name: Signatures V4 description: >- Send PDFs for e-signature and download the signed, eIDAS-grade document (DocuSeal-compatible) - name: WhatsApp V4 description: >- Send and receive WhatsApp messages by phone number and read conversation history - name: One Time Booking Link V4 description: Create single-use booking links - name: availability-exception description: Override availability for specific dates - name: Booking Link V4 description: Configure various booking page types - name: Personal Page V4 description: Manage user profile pages - name: Handoff V4 description: Reassign meetings to other hosts - name: Calendar Auth V4 description: OAuth callbacks for calendar providers - name: CRM Contacts description: >- Create, find, and update the people in your CRM, including their custom data fields - name: CRM Deals description: >- Create, update, and track deals through pipeline stages (incl. per-deal activity history) - name: CRM Pipelines description: Manage pipelines and their stages - name: Data Fields description: >- Define the custom fields a contact can carry; their `name` is the key used in a contact's additionalData - name: Invoicing Documents description: >- Offers and invoices: create a draft, finalize it into a numbered e-invoice, send it, record payments, and run Mahnwesen - name: Invoicing Products description: Reusable products for invoice line items - name: Invoicing Settings description: Seller details, tax treatment, bank accounts, and number ranges - name: Invoicing Recurring description: >- Recurring schedules, billing runs over completed meetings, buyer prefill, and DATEV export - name: Queue V4 description: Round-robin and queue-based routing (Beta) - name: Queue User Group V4 description: Manage queue user groups (Beta) - name: Meeting Type Template V4 description: Reusable meeting type configurations (Beta) - name: Attendee Pending V4 description: Manage pending attendee approvals (Beta) - name: Provisional Booking V4 description: Manage provisional/unconfirmed bookings (Beta) paths: /v4/whatsapp/messages: post: tags: - WhatsApp V4 summary: Send a WhatsApp message description: >- Sends a text, template, or media message addressed by phone number. The conversation is created or reused automatically. Free-form text and media require an open 24-hour customer-service window (since the contact last messaged you); approved templates can be sent anytime. Outside the window, text/media return 403 — send a template to re-engage. operationId: sendMessage parameters: [] requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/SendWhatsappMessageV4Dto' responses: '201': description: Message accepted by WhatsApp. content: application/json: schema: $ref: '#/components/schemas/WhatsappMessageResource' '400': $ref: '#/components/responses/BadRequest' '401': $ref: '#/components/responses/Unauthorized' '403': description: >- WhatsApp add-on missing, or the 24h window is closed for a text/media send. '429': $ref: '#/components/responses/TooManyRequests' security: - ApiUserHeader: [] - JWT: [] - ApiKey: [] components: schemas: SendWhatsappMessageV4Dto: type: object properties: to: type: string maxLength: 140 description: >- Recipient address: a phone number (E.164 preferred, e.g. "+491234567890"; "00" prefixes and separators are normalized) or a WhatsApp business-scoped user id (BSUID, e.g. "US.13491208655302741918") for contacts who have adopted a WhatsApp username. example: '+491234567890' type: description: Which kind of message to send. allOf: - $ref: '#/components/schemas/WhatsappMessageKind' contactName: type: string maxLength: 255 description: >- Contact name to set when a new conversation is created for this number. text: type: string maxLength: 4096 description: Message body. Required when `type` is `text`. example: Hi! Your order has shipped. template: description: Template payload. Required when `type` is `template`. allOf: - $ref: '#/components/schemas/WhatsappTemplatePayloadDto' media: description: Media payload. Required when `type` is `media`. allOf: - $ref: '#/components/schemas/WhatsappMediaPayloadDto' required: - to - type WhatsappMessageResource: type: object properties: id: type: string description: meetergo message id. conversationId: type: string description: Conversation this message belongs to. waMessageId: type: string description: WhatsApp's own message id (wamid). direction: enum: - inbound - outbound type: string type: type: string description: Message kind (text, image, document, template, ...). status: type: string enum: - pending - sent - delivered - read - failed description: Delivery status. Inbound messages are always `delivered`. text: type: string description: Text body, or the caption for a media message. mediaUrl: type: string description: URL of the attached media, if any. mediaMimeType: type: string description: MIME type of the attached media. mediaFilename: type: string description: Filename of the attached document. templateName: type: string description: Template name, for template messages. errorMessage: type: string description: Failure reason from WhatsApp, set when `status` is `failed`. createdAt: format: date-time type: string description: When the message was created (ISO 8601). required: - id - conversationId - waMessageId - direction - type - status - createdAt WhatsappMessageKind: type: string enum: - text - template - media description: Which kind of message to send. WhatsappTemplatePayloadDto: type: object properties: name: type: string maxLength: 512 description: Approved template name as registered in WhatsApp Manager. example: appointment_reminder language: type: string maxLength: 35 description: Template language/locale code. example: en_US params: description: >- Positional values substituted into the template body placeholders ({{1}}, {{2}}, ...). example: - John - Tuesday at 10:00 type: array items: type: string buttonUrlParams: type: object description: >- Dynamic URL-button suffixes keyed by zero-based button index, for templates with dynamic URL buttons. example: '0': cancel/abc123 required: - name - language WhatsappMediaPayloadDto: type: object properties: url: type: string maxLength: 2048 format: uri description: >- Public HTTPS URL of the media to send. Must be reachable by WhatsApp (e.g. a presigned URL). HTTP is rejected. example: https://files.example.com/invoice.pdf mimeType: type: string maxLength: 255 pattern: /^[\w.+-]+\/[\w.+-]+$/ description: MIME type of the media. Determines how WhatsApp renders it. example: application/pdf filename: type: string maxLength: 255 description: Original filename, shown for documents. example: invoice.pdf caption: type: string maxLength: 1024 description: Caption shown beneath images, videos and documents. required: - url - mimeType ApiError: type: object required: - statusCode - message properties: statusCode: type: integer example: 400 message: oneOf: - type: string - type: array items: type: string description: >- A sentence, or the list of field constraints that failed. Validation errors name the offending property. example: - limit must not be greater than 100 error: type: string example: BadRequestException responses: BadRequest: description: >- The request did not validate. `message` lists the constraints that failed. content: application/json: schema: $ref: '#/components/schemas/ApiError' Unauthorized: description: Missing, malformed, or expired credentials. content: application/json: schema: $ref: '#/components/schemas/ApiError' TooManyRequests: description: Rate limited. Back off and retry. content: application/json: schema: $ref: '#/components/schemas/ApiError' securitySchemes: ApiUserHeader: type: apiKey in: header name: x-meetergo-api-user-id description: >- User ID to act on behalf of. Platform API Keys only (required with an API Key unless the endpoint states otherwise). Requests authenticated with a Personal Access Token are rejected if this header names another user. JWT: scheme: bearer bearerFormat: JWT type: http description: JWT Bearer token for standard user authentication ApiKey: scheme: bearer bearerFormat: API Key type: http description: >- Bearer token: a Platform API Key (format: ak_live::) or a Personal Access Token (format: rgo-...). PATs always act as the token owner. ````