Change the settings

PATCH https://app.sendapp.ai/api/voice/config

Changes the Voice AI settings of one assistant, like the Voice AI page. Send only the fields that change: the ones you leave out stay as they are. It applies from the next calls.

Only the fields you send are checked: a field you leave out stays as it is. A field sent empty on purpose, for example "language": "", answers 422.

Only these fields can be changed: any other field (for example recording or the line's data) answers 422.

With an expired plan the change is refused with 403 and code: plan_expired. Limit: 30 changes a minute per key.

Common errors: 401 API key missing or wrong — 403 plan without API access or without Voice AI, Voice AI app switched off, account suspended — 404 call or assistant that does not exist or is not yours — 422 invalid parameters — 429 too many requests: try again after the seconds given in Retry-After.

Parameters

8 · 2 required

apikey required

Your API Key (the X-API-Key header also works).

assistant_id required

The assistant (assistant_id from List voice assistants).

language optional

Language: it, en, es, fr, de, pt.

voice_id optional

The voice (as in voice_id of the settings).

voice_label optional

The name shown for the voice.

first_message optional

What the assistant says when it answers (max 500 characters).

system_prompt optional

The instructions for the phone assistant (max 4000 characters).

greet_caller_by_name optional

true to greet by name callers already in your contacts.

Need help with the integration? info@sendapp.live

Request

curl -X PATCH 'https://app.sendapp.ai/api/voice/config?assistant_id=YOUR_ACCOUNT_TOKEN' \
  -H 'X-API-Key: YOUR_API_KEY' \
  -H 'Content-Type: application/json' \
  -d '{
    "first_message": "Studio Rossi, buongiorno! Come posso aiutarla?",
    "greet_caller_by_name": true
  }'

<?php
$ch = curl_init('https://app.sendapp.ai/api/voice/config?assistant_id=YOUR_ACCOUNT_TOKEN');
curl_setopt_array($ch, [
    CURLOPT_CUSTOMREQUEST => 'PATCH',
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_HTTPHEADER => ['X-API-Key: YOUR_API_KEY', 'Content-Type: application/json'],
    CURLOPT_POSTFIELDS => json_encode(['language' => 'en']),
]);
$res = json_decode(curl_exec($ch), true);
curl_close($ch);

const res = await fetch('https://app.sendapp.ai/api/voice/config?assistant_id=YOUR_ACCOUNT_TOKEN', {
  method: 'PATCH',
  headers: { 'X-API-Key': 'YOUR_API_KEY', 'Content-Type': 'application/json' },
  body: JSON.stringify({ first_message: 'Studio Rossi, buongiorno!' })
});
console.log(await res.json());

Response

{
  "status": "success",
  "config": {
    "assistant_id": "YOUR_ACCOUNT_TOKEN",
    "assistant_name": "Studio Dentistico Rossi",
    "language": "it",
    "voice_id": "it-IT-Chirp3-HD-Aoede",
    "voice_label": "Aoede",
    "first_message": "Studio Rossi, buongiorno! Come posso aiutarla?",
    "system_prompt": "Sei l'assistente telefonico dello studio...",
    "greet_caller_by_name": true,
    "recording_enabled": true,
    "ai_mode": "always",
    "phone_number": "+390212345678",
    "updated_at": "2026-11-05T09:30:02Z"
  }
}

{
  "status": "error",
  "message": "These fields cannot be changed through the API: recording_enabled. Allowed: language, voice_id, voice_label, first_message, system_prompt, greet_caller_by_name."
}