Send a voice note to an individual recipient | Message Blue

curl -X POST https://api.messageblue.ai/sendVoiceNote \
     -H "X-App-Id: <apiKey>" \
     -H "Content-Type: application/json" \
     -d '{
  "to": "+16475137145",
  "voiceNote": {
    "url": "https://storage.example.com/voice-notes/meeting-summary.m4a"
  }
}'

{
  "ok": true,
  "data": {
    "id": "d290f1ee-6c54-4b01-90e6-d701748f0851",
    "status": "sent",
    "type": "result",
    "from": "+14155550123",
    "to": "+16475137145",
    "groupId": "group-12345",
    "text": "Here is the voice note from our last meeting.",
    "attachments": [
      "https://storage.example.com/voice-notes/meeting-summary.caf"
    ],
    "messageGuid": "msg-7890abc",
    "chatGuid": "chat-4567def",
    "outbound": true,
    "iMessageNumber": "+14155550123",
    "idempotencyKey": "abc123xyz789"
  },
  "meta": {
    "requestId": "550e8400-e29b-41d4-a716-446655440000",
    "timestamp": "2026-07-10T06:00:00.000Z"
  }
}

Accepts a voiceNote URL and forwards it as an attachment to /sendIndividualMessage. The Mac agent converts common audio formats to .caf for native iMessage voice note bubbles.

Authentication

X-App-Idstring

Your MessageBlue App ID, sent in clear on every request. It is paired with request signing: each request is also signed with your App Secret (see the Authentication tag). The App Secret itself is NEVER transmitted — it is only the HMAC signing key.

Request

This endpoint expects an object.

tostringRequired

voiceNoteobjectRequired

fromstringOptional

textstringOptional

Optional caption sent with the voice note

status_callbackstringOptionalformat: "uri"

Response

Voice note dispatched

okboolean

dataobject

Endpoint-specific payload wrapped in a standard success envelope.

metaobject

Errors

400

Bad Request Error

Authentication

Headers

Request

Response

Errors