Sending messages

Before sending

WhatsApp has two Meta rules that the API applies exactly like the app:

• 24-hour window: up to 24 h after the contact's last message you can send text, buttons or a list. The conversation shows it in window.open and window.expires_at.
• Outside the window, only an approved template (GET /v1/templates?status=approved).

Contacts who opted out don't get templates; you can reply only if they write again.

Text

curl -X POST https://api.converzap.com/v1/conversations/CONVERSATION_ID/messages \
  -H "Authorization: Bearer czk_live_YOUR_KEY" \
  -H "Idempotency-Key: 6c1f0e2a-5b7d-4c1e-9b1a-1f2e3d4c5b6a" \
  -H "Content-Type: application/json" \
  -d '{ "type": "text", "text": "Hi Ana! Your order is on its way." }'

Template (outside the window)

{
  "type": "template",
  "template": {
    "name": "appointment_reminder",
    "language": "pt_BR",
    "params": { "body": ["Ana", "tomorrow at 3pm"] }
  }
}

Variables: body as a list ({{1}}, {{2}}…) or an object (named: { "name": "Ana" }), header the same, buttons: { "0": "url-suffix" }. template.id also works instead of name + language.

Buttons and list

{
  "type": "interactive",
  "interactive": {
    "type": "buttons",
    "body": "Confirm tomorrow's appointment?",
    "buttons": [{ "id": "yes", "title": "Confirm" }, { "id": "no", "title": "Reschedule" }]
  }
}

The contact's reply arrives as a text message with the button title (and in the message.received webhook).

What happens when you send

• The sender becomes the conversation assignee if it had none.
• The number's AI agent logs the human reply and pauses, if configured to.
• The message shows in the inbox as sent by the key's user.

Common errors

Always send Idempotency-Key: if the network drops and you retry, the message isn't sent twice.