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

# Voice call button

> Send a button the user taps to call your business on WhatsApp

Send a `voice_call` interactive message to add a call button to a message. Every parameter is optional.

```bash REST API icon="code" theme={null}
curl -X POST 'https://api.kapso.ai/meta/whatsapp/v24.0/647015955153740/messages' \
  -H 'X-API-Key: YOUR_API_KEY' \
  -H 'Content-Type: application/json' \
  -d '{
    "messaging_product": "whatsapp",
    "recipient_type": "individual",
    "to": "15551234567",
    "type": "interactive",
    "interactive": {
      "type": "voice_call",
      "body": {
        "text": "Need help with your order? Call us."
      },
      "action": {
        "name": "voice_call",
        "parameters": {
          "display_text": "Call support",
          "ttl_minutes": 1440,
          "payload": "order-4471"
        }
      }
    }
  }'
```

## Parameters

| Field | Type | Description |
| - | - | - |
| `display_text` | string | Button label, 20 characters or fewer. Defaults to `Call Now`. |
| `ttl_minutes` | integer | Minutes the button stays active, between 1 and 43200. Defaults to 10080 (7 days). |
| `payload` | string | Tracking string, 512 characters or fewer. Returned as `cta_payload` in call webhooks. |

Omit `action.parameters` entirely to use Meta's defaults:

```json theme={null}
{
  "type": "voice_call",
  "body": { "text": "Need help with your order? Call us." },
  "action": { "name": "voice_call" }
}
```