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

# Send Text Message

> Send a plain WhatsApp text message to any mobile number via the ChatSyncs API — request parameters, GET and POST examples, and the success/error response shapes. Use when a developer asks how to send a WhatsApp message from their own server/code, or why their send request returned a subscriber-limit error.

Sends a WhatsApp text message to any mobile number from one of your connected WhatsApp
numbers.

<Info>
  This sends a **session message** — only deliverable if the recipient messaged your business
  within the last 24 hours (a customer-initiated conversation). To message someone outside that
  window, use an approved **Template Message** instead — see
  [Creating a WhatsApp Message Template](https://help.chatsyncs.com/docs/create-whatsapp-template).
</Info>

<Note>
  A success response means ChatSyncs accepted the message. If WhatsApp can't deliver it afterwards, that shows up as
  `message_status` `failed` with a `failed_reason` in
  [Get Delivery Message Status](/developer-api/whatsapp/get-message-status) and
  [Get Conversation](/developer-api/whatsapp/get-conversation). Outside the 24-hour window the request itself is refused
  with `Sending message outside 24 hour window is not allowed. You can only send template message to this user.`
</Note>


## OpenAPI

````yaml POST /whatsapp/send
openapi: 3.1.0
info:
  title: ChatSyncs Developer API
  version: 1.0.0
  description: >-
    REST API for sending WhatsApp messages and managing subscribers through
    ChatSyncs.


    **Authentication.** Send your key as the `apiToken` parameter, or as
    `Authorization: Bearer <key>` — both work on every endpoint **except Custom
    Fields List**, which only accepts the `apiToken` parameter (a Bearer header
    alone is answered with *The api token field is required.*). A wrong key
    returns HTTP 401 `{"status":"0","message":"Unauthenticated."}`; no key at
    all redirects to the login page.


    **Methods.** Every endpoint accepts both GET and POST with the same
    parameters, except Upload Media, which is POST-only. Use POST for anything
    that changes data.


    **Errors.** Failures usually come back as HTTP 200 with `"status":"0"` and
    the reason in `message`, so always check `status`. `status` is the string
    `"1"` or `"0"` on most endpoints and a boolean on a few.


    **Lists.** Endpoints that return rows put them in `message` as a list; there
    is no `data` field (Custom Fields List is the exception and uses `data`).
servers:
  - url: https://platform.chatsyncs.com/api/v1
security: []
paths:
  /whatsapp/send:
    post:
      tags:
        - WhatsApp API
      summary: Send Text Message
      description: >-
        A success response means ChatSyncs accepted the message for delivery. If
        WhatsApp later cannot deliver it, that appears as `message_status`
        `failed` with a `failed_reason` in Get Delivery Message Status and Get
        Conversation.
      operationId: sendTextMessage
      requestBody:
        required: true
        content:
          application/x-www-form-urlencoded:
            schema:
              type: object
              properties:
                apiToken:
                  type: string
                  description: >-
                    Your ChatSyncs API key (not a WhatsApp/Meta access token).
                    [Where to find
                    it](/developer-api/finding-ids#api-token-apitoken).
                  example: API-KEY
                phone_number_id:
                  type: string
                  description: >-
                    The WhatsApp account's phone number ID. [Where to find
                    it](/developer-api/finding-ids#phone-number-id-phone_number_id).
                  example: PHONE-NUMBER-ID
                phone_number:
                  type: string
                  description: >-
                    The subscriber's phone number, with country code, digits
                    only.
                  example: PHONE-NUMBER
                message:
                  type: string
                  description: >-
                    The text content to send. On a GET request, this must be
                    URL-encoded.
                  example: TEXT-MESSAGE
              required:
                - apiToken
                - phone_number_id
                - phone_number
                - message
      responses:
        '200':
          description: >-
            Standard ChatSyncs response. `status` is `"1"` on success and `"0"`
            on failure.
          content:
            application/json:
              schema:
                type: object
                properties:
                  status:
                    type: string
                    description: '`"1"` = success, `"0"` = failure.'
                  message:
                    type: string
                    description: Human-readable result message.
              examples:
                success:
                  summary: Success
                  value:
                    status: '1'
                    wa_message_id: >-
                      wamid.HBgNODgwMTcyMzMwOTAwMxUCABEYEjlGQkY3MEFEMEVGODhCNDkxNQA=
                    message: Message sent successfully.
                error:
                  summary: Missing message
                  value:
                    status: '0'
                    message: The parameter text.body is required.
                outsideWindow:
                  summary: Outside the 24-hour window
                  value:
                    status: '0'
                    message: >-
                      Sending message outside 24 hour window is not allowed. You
                      can only send template message to this user.
        '401':
          description: >-
            `apiToken` is wrong. (With no token at all the API redirects to the
            login page with HTTP 302 instead of returning JSON.)
          content:
            application/json:
              schema:
                type: object
                properties:
                  status:
                    type: string
                  message:
                    type: string
              examples:
                unauthenticated:
                  summary: Wrong apiToken
                  value:
                    status: '0'
                    message: Unauthenticated.

````

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