Data endpoint

Dynamic WhatsApp Flows call your data endpoint to fetch screen content at runtime.

How it works

User opens the flow in WhatsApp
Meta sends an encrypted request to Kapso
Kapso decrypts and forwards to your function
Your function returns screen data
Kapso encrypts and returns to Meta
User sees the dynamic content

Setup requirements

Before using data endpoints:

WhatsApp phone number - Set in the Info tab
Flows encryption - One-time setup per phone number (Kapso handles the key exchange)
Function - Your code that returns screen data

Request format

Kapso sends this payload to your function:

{
  "source": "whatsapp_flow",
  "flow": {
    "id": "kapso_flow_id",
    "meta_flow_id": "meta_flow_id"
  },
  "data_exchange": {
    "version": "3.0",
    "action": "data_exchange",
    "screen": "CURRENT_SCREEN",
    "data": {},
    "flow_token": "unique_session_token"
  },
  "signature_valid": true,
  "received_at": "2024-01-15T10:30:00Z"
}

The data_exchange object contains Meta’s original payload with the current screen and any user-submitted data.

Response format

Your function must return:

{
  "version": "3.0",
  "screen": "NEXT_SCREEN_ID",
  "data": {
    "field_name": "value"
  }
}

Field	Description
`version`	Always `"3.0"`
`screen`	Screen ID to display next
`data`	Key-value pairs matching screen’s data schema

Completing the flow

To end the flow and close it:

{
  "version": "3.0",
  "screen": "SUCCESS",
  "data": {
    "extension_message_response": {
      "params": {
        "flow_token": "from_request"
      }
    }
  }
}

Limits

Limit	Value
Response timeout	15 seconds
Rate limit	100 requests/minute per flow

Error handling

If your function fails or times out, Kapso returns an error screen to the user. Check the Invocations in your function dashboard for debugging.

Getting started

WhatsApp

For your team

Onboard customers

Automations

How it works

Setup requirements

Request format

Response format

Completing the flow

Limits

Error handling

​How it works

​Setup requirements

​Request format

​Response format

​Completing the flow

​Limits

​Error handling

How it works

Setup requirements

Request format

Response format

Completing the flow

Limits

Error handling