Send Custom Message

Send a message to a customer inside a conversation that is already open. Unlike Send Template — which is used to start the conversation — this endpoint assumes the customer already started a conversation or recently replied to a template, so the service window is still active.

POST https://api.platica.mx/v1/messages

Request body

{
  "channelId": "521234567890",
  "conversationId": "521234567890",
  "content": "¡Hola! ¿En qué puedo ayudarte?",
  "client": {
    "name": "José",
    "customFields": {
      "placas": "ABC123"
    }
  }
}

Body parameters

Message types

content can be plain text or a structured object. When it is an object, you must specify type, and the shape of content depends on the type.

Text

Shorthand form:

{
  "channelId": "521234567890",
  "conversationId": "521234567890",
  "content": "¡Hola! ¿En qué puedo ayudarte?"
}

Explicit form:

{
  "channelId": "521234567890",
  "conversationId": "521234567890",
  "type": "text",
  "content": { "text": "¡Hola! ¿En qué puedo ayudarte?" }
}

Image

{
  "channelId": "521234567890",
  "conversationId": "521234567890",
  "type": "image",
  "content": {
    "image": {
      "url": "https://cdn.assets.com/foto.jpg",
      "caption": "Aquí está la foto que me pediste"
    }
  }
}

Video

{
  "channelId": "521234567890",
  "conversationId": "521234567890",
  "type": "video",
  "content": {
    "video": {
      "url": "https://cdn.assets.com/video.mp4",
      "caption": "Mira este video"
    }
  }
}

Document / file

{
  "channelId": "521234567890",
  "conversationId": "521234567890",
  "type": "file",
  "content": {
    "file": {
      "url": "https://cdn.assets.com/factura.pdf",
      "filename": "factura-2025-09.pdf",
      "caption": "Tu factura del mes"
    }
  }
}

Audio

{
  "channelId": "521234567890",
  "conversationId": "521234567890",
  "type": "audio",
  "content": {
    "audio": {
      "url": "https://cdn.assets.com/nota.ogg"
    }
  }
}

Interactive messages

Interactive messages (buttons, lists, and flows) are available only on WhatsApp.

{
  "channelId": "521234567890",
  "conversationId": "521234567890",
  "type": "interactive",
  "content": {
    "type": "button",
    "body": { "text": "¿Quieres confirmar tu cita?" },
    "action": {
      "buttons": [
        { "id": "confirmar", "title": "Sí, confirmar" },
        { "id": "reagendar", "title": "Reagendar" },
        { "id": "cancelar", "title": "Cancelar" }
      ]
    }
  }
}

{
  "channelId": "521234567890",
  "conversationId": "521234567890",
  "type": "interactive",
  "content": {
    "type": "list",
    "body": { "text": "Elige el horario que prefieras" },
    "action": {
      "button": "Ver horarios",
      "sections": [
        {
          "title": "Esta semana",
          "rows": [
            { "id": "lun-10", "title": "Lunes 10:00", "description": "Disponible" },
            { "id": "mar-12", "title": "Martes 12:00", "description": "Disponible" }
          ]
        }
      ]
    }
  }
}

{
  "channelId": "521234567890",
  "conversationId": "521234567890",
  "type": "interactive",
  "content": {
    "type": "flow",
    "body": { "text": "Completa tu registro en menos de un minuto" },
    "action": {
      "parameters": {
        "flow_id": "1234567890",
        "flow_cta": "Empezar"
      }
    }
  }
}

Instruction to the agent

An instruction is not sent to the customer: it acts on the agent operating the conversation. It is useful when you are supervising the chat through the API and want the agent to wait or resume control. The mode field defines the behavior.

{
  "channelId": "521234567890",
  "conversationId": "521234567890",
  "type": "instruction",
  "content": {
    "text": "Espera a que el cliente confirme la cita antes de continuar.",
    "mode": "wait"
  }
}

Behavior by mode

• wait: records the instruction as a system message in the history and leaves the conversation waiting for the customer's next message. The agent does not reply immediately; when the next customer message arrives, it reads the instruction as context.
• resume: marks the conversation as resumed and prompts the agent to continue the flow using the instruction as guidance. The agent can decide whether to reply to the customer based on its own logic.

{
  "channelId": "521234567890",
  "conversationId": "521234567890",
  "type": "instruction",
  "content": {
    "text": "Continúa con el flujo de venta y ofrece un descuento del 10%.",
    "mode": "resume"
  }
}

Scheduling

Just like in Send Template , you can send the message immediately, after a delay, or at a specific date and time. You can then retrieve, reschedule, or cancel it by messageId .

Response

The response shape depends on whether the message is sent immediately, with a delay, or scheduled.

Immediate send:

{
  "messageId": "msg_123xyz",
  "status": "sent",
  "timestamp": "2026-09-20T20:00:00Z"
}

With delay (HTTP 202):

{
  "messageId": "msg_123xyz",
  "kind": "service",
  "status": "delayed",
  "timestamp": "2026-09-20T20:00:00Z",
  "executeAt": "2026-09-20T20:00:05.000Z",
  "delayMs": 5000
}

With scheduleTime (HTTP 202):

{
  "messageId": "msg_123xyz",
  "kind": "service",
  "status": "scheduled",
  "timestamp": "2026-09-20T20:00:00Z",
  "executeAt": "2026-10-16T00:40:00.000Z",
  "scheduledTime": "2026-10-15T18:40:00"
}

Sends with delay or scheduleTime are accepted but have not been sent yet. See Scheduled Messages for their states and execution rules.

Channel rules

WhatsApp

• Templates are required to start the conversation. Once the customer replies, the service window stays open for 24 hours and you can send any message type until it closes.
• Every customer message resets the window.
• Supports text, images, videos, files, audio, buttons, lists, and flows.

Instagram and Facebook

• Support text, images, videos, files, and audio. Interactive messages (buttons, lists, flows) are not available outside WhatsApp.
• The window is calculated from the latest user message; check canSendDirectMessage before sending.

Internal channels (chats with agents)

POST /v1/messages also works on the internal conversations created by the Chat API . Identify the thread with the chat's conversationId (chat_*) or its internal channelId:

{
  "channelId": "workspace-ws_001-agent-agent_001",
  "conversationId": "chat_01JCHAT23456789",
  "content": "An advisor will review your case in a few minutes."
}

• Supported types: text, image, video, file, audio, and instruction. interactive and email messages and templates are exclusive to external channels and return 422 on an internal channel.
• Instructions to the agent (wait / resume) work exactly the same as on external channels.
• There is no service window on internal channels: canSendDirectMessage is always true.

Channel compatibility matrix

¹ email is only available on connected email channels; on an internal channel it returns 422.

Checking status

Confirm your message was delivered:

1. From the platform's inbox.
2. Using the Get Conversation endpoint.