> ## Documentation Index
> Fetch the complete documentation index at: https://api-docs.voicecheap.ai/docs/llms.txt
> Use this file to discover all available pages before exploring further.
# Design a voice
> Create voice candidates from a description using your voice design allowance. Listen with voices_preview_get, then save your chosen preview.
Create voice candidates from a description using your voice design allowance. Listen with voices\_preview\_get, then save your chosen preview.
```http theme={null}
POST https://api.voicecheap.ai/v1/actions/voices_design
```
## Authentication and permissions
Send a VoiceCheap API key in this header. Authorization: Bearer with the same API key is also supported. OAuth access tokens are accepted only by
MCP, not by this REST endpoint.
Required permissions: `voices:write`.
An active paid subscription is required. Permissions do not change team roles, resource ownership, media credits, or plan limits.
## Parameters
Optional at the transport boundary: the server injects an identifier before validation when omitted. Supply your own stable UUID v4 to recover safely from a lost response.
Format: "uuid". Pattern: `^[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-4[0-9a-fA-F]{3}-[89abAB][0-9a-fA-F]{3}-[0-9a-fA-F]{12}$`.
Text value.
Minimum length: 1. Maximum length: 80.
Text value.
Minimum length: 1. Maximum length: 2000.
Text value.
Maximum length: 35. Pattern: `^[a-z]{2,3}(-[A-Za-z0-9]{2,8})*$`.
The JSON Schema below preserves the exact field names, nested types, defaults, bounds, and accepted values exposed by discovery. Additional cross-field rules are listed in the operation notes.
```json theme={null}
{
"type": "object",
"properties": {
"requestId": {
"description": "UUID v4 for this action. Reuse the same ID with identical arguments on retries.",
"type": "string",
"format": "uuid",
"pattern": "^[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-4[0-9a-fA-F]{3}-[89abAB][0-9a-fA-F]{3}-[0-9a-fA-F]{12}$"
},
"name": {
"type": "string",
"minLength": 1,
"maxLength": 80
},
"description": {
"type": "string",
"minLength": 1,
"maxLength": 2000
},
"language": {
"type": "string",
"maxLength": 35,
"pattern": "^[a-z]{2,3}(-[A-Za-z0-9]{2,8})*$"
}
},
"required": ["name", "description"],
"additionalProperties": false
}
```
## Idempotency
Use a UUID v4 in requestId or the Idempotency-Key HTTP header for each mutation. Reuse the same identifier and identical arguments after a network failure. If both are supplied, they must match. Replaying a saved request does not repeat the operation or charge another monthly call. Failed or interrupted requests are not restarted automatically.
Every mutation can return HTTP 202 when a retry finds the same request still running, even when its first execution is normally synchronous. If execution completed but resultStored is false, a retry returns HTTP 200 with saved request state instead of the original result. Retrieve the output through its domain history, result, or download action.
## Request examples
Replace example resource identifiers and media keys with values returned for your account. Keep the request identifier stable when retrying the same mutation.
```bash cURL theme={null}
curl --request POST 'https://api.voicecheap.ai/v1/actions/voices_design' \
--header "x-api-key: $VOICECHEAP_API_KEY" \
--header 'Content-Type: application/json' \
--data '{"requestId":"284a861a-4da8-4d67-ad48-8123e76c8e91","name":"Studio narrator","description":"A warm, clear English narrator with steady pacing and a natural conversational delivery.","language":"en"}'
```
```javascript JavaScript theme={null}
const input = {
requestId: '284a861a-4da8-4d67-ad48-8123e76c8e91',
name: 'Studio narrator',
description: 'A warm, clear English narrator with steady pacing and a natural conversational delivery.',
language: 'en',
};
const response = await fetch('https://api.voicecheap.ai/v1/actions/voices_design', {
method: 'POST',
headers: {
'x-api-key': process.env.VOICECHEAP_API_KEY,
'Content-Type': 'application/json',
},
body: JSON.stringify(input),
});
const body = await response.json();
if (!response.ok) throw new Error(body.code + ': ' + body.message);
console.log(body);
```
```python Python theme={null}
import os
import requests
response = requests.post(
"https://api.voicecheap.ai/v1/actions/voices_design",
headers={"x-api-key": os.environ["VOICECHEAP_API_KEY"]},
json={"requestId": "284a861a-4da8-4d67-ad48-8123e76c8e91", "name": "Studio narrator", "description": "A warm, clear English narrator with steady pacing and a natural conversational delivery.", "language": "en"},
timeout=120,
)
body = response.json()
if not response.ok:
raise RuntimeError(f"{body.get('code')}: {body.get('message')}")
print(body)
```
## Response
This operation returns HTTP 202 while running. Save requestId and poll action\_request\_get with that identifier and the original operation name. Polling states are running, completed, failed, and interrupted. A completed result can point to a separate media job; continue with the operation-specific status or output action.
All active unsaved previews and updated creation allowances, including two new designed voice candidates.
```json HTTP 202 theme={null}
{
"data": {
"requestId": "284a861a-4da8-4d67-ad48-8123e76c8e91",
"status": "running",
"pollAction": "action_request_get",
"pollAfterSeconds": 5
},
"requestId": "284a861a-4da8-4d67-ad48-8123e76c8e91"
}
```
```json HTTP 200 theme={null}
{
"data": {
"voicePreviews": [
{
"id": "44444444-4444-4444-8444-444444444444",
"kind": "design",
"name": "Studio narrator 1",
"previewUrl": "https://files.example.com/designed-narrator-1.wav",
"expiresAt": 1792238400000,
"durationSeconds": 8
},
{
"id": "55555555-5555-4555-8555-555555555555",
"kind": "design",
"name": "Studio narrator 2",
"previewUrl": "https://files.example.com/designed-narrator-2.wav",
"expiresAt": 1792238400000,
"durationSeconds": 9
}
],
"creationUsage": {
"cloneTrial": {
"limit": 1,
"used": 0,
"remaining": 1
},
"design": {
"limit": 5,
"used": 1,
"remaining": 4,
"resetsAt": 1792195200000
},
"previewExpiresAfterHours": 24
}
},
"requestId": "284a861a-4da8-4d67-ad48-8123e76c8e91"
}
```
```json HTTP 202 replay_running theme={null}
{
"data": {
"requestId": "284a861a-4da8-4d67-ad48-8123e76c8e91",
"operation": "voices_design",
"createdAt": 1792144800000,
"updatedAt": 1792144820000,
"status": "running",
"pollAfterSeconds": 5
},
"requestId": "284a861a-4da8-4d67-ad48-8123e76c8e91"
}
```
```json HTTP 200 replay_completed_without_result theme={null}
{
"data": {
"requestId": "284a861a-4da8-4d67-ad48-8123e76c8e91",
"operation": "voices_design",
"createdAt": 1792144800000,
"updatedAt": 1792144820000,
"status": "completed",
"resultStored": false,
"message": "The action completed. Retrieve its output from the corresponding history or resource action."
},
"requestId": "284a861a-4da8-4d67-ad48-8123e76c8e91"
}
```
## Result fields
| Field | Description |
| - | - |
| `data.voicePreviews` | All currently active, unsaved previews for this account, including candidates from earlier requests. |
| `data.voicePreviews[].id` | Preview UUID v4 used by voices\_preview\_get and voices\_save\_preview. |
| `data.voicePreviews[].kind` | clone or design. |
| `data.voicePreviews[].name` | Preview display name; designed candidates append a number to the requested name. |
| `data.voicePreviews[].previewUrl` | Temporary playable audio URL. Request a fresh URL with voices\_preview\_get while the preview remains active. |
| `data.voicePreviews[].expiresAt` | Preview expiry as a Unix timestamp in milliseconds. |
| `data.voicePreviews[].durationSeconds` | Preview audio duration in seconds. |
| `data.creationUsage.cloneTrial` | Lifetime clone preview trial allowance with limit, used, and remaining. |
| `data.creationUsage.design` | Daily voice design allowance with limit, used, remaining, and resetsAt in Unix milliseconds. |
| `data.creationUsage.previewExpiresAfterHours` | Lifetime of an unsaved preview in hours, currently 24. |
## Recover and poll this request
Use the same identifier even after a lost connection. If resultStored is false, retrieve the output through the corresponding history, result, or download action. Never start a second generation merely to check progress.
```bash theme={null}
curl --request POST 'https://api.voicecheap.ai/v1/actions/action_request_get' \
--header "x-api-key: $VOICECHEAP_API_KEY" \
--header 'Content-Type: application/json' \
--data '{"requestId":"284a861a-4da8-4d67-ad48-8123e76c8e91","operation":"voices_design"}'
```
```json HTTP 200 theme={null}
{
"data": {
"requestId": "284a861a-4da8-4d67-ad48-8123e76c8e91",
"operation": "voices_design",
"status": "completed",
"createdAt": 1792144800000,
"updatedAt": 1792144820000,
"resultStored": true,
"result": {
"voicePreviews": [
{
"id": "44444444-4444-4444-8444-444444444444",
"kind": "design",
"name": "Studio narrator 1",
"previewUrl": "https://files.example.com/designed-narrator-1.wav",
"expiresAt": 1792238400000,
"durationSeconds": 8
},
{
"id": "55555555-5555-4555-8555-555555555555",
"kind": "design",
"name": "Studio narrator 2",
"previewUrl": "https://files.example.com/designed-narrator-2.wav",
"expiresAt": 1792238400000,
"durationSeconds": 9
}
],
"creationUsage": {
"cloneTrial": {
"limit": 1,
"used": 0,
"remaining": 1
},
"design": {
"limit": 5,
"used": 1,
"remaining": 4,
"resetsAt": 1792195200000
},
"previewExpiresAfterHours": 24
}
}
}
}
```
## Operation notes
* Use a UUID v4 requestId for this mutation and reuse it with identical arguments when retrying. Long-running actions first return a running request; this example is the completed handler result available from action\_request\_get.
* name contains 1–80 trimmed characters. description contains 1–2,000 trimmed characters. Optional language accepts a 2–3 letter code with optional subtags and a maximum of 35 characters.
* A successful design request creates two kind: design candidates with numbered names and consumes one daily design request. Paid plans allow five requests per UTC day; inspect creationUsage.design for the current count and reset time.
* Candidates last 24 hours and are not saved reusable TTS voices. Listen with voices\_preview\_get, then save a selected candidate with voices\_save\_preview.
* The response includes earlier active previews as well as the new candidates. No saved voice slot is occupied until a candidate is saved.
* Speech history and custom voices belong to the authenticated account. Team billing does not grant access to another member’s speech or voices.
## Usage
Each successful invocation consumes one monthly API/MCP call. Media credits and the operation's own generation allowances also apply.
## Errors
| HTTP status | Code | Meaning or recovery |
| - | - | - |
| 400 | `CREDENTIAL_IN_QUERY` | Credentials were supplied in an access\_token or api\_key query parameter. Send credentials in headers. |
| 400 | `IDEMPOTENCY_CONFLICT` | The Idempotency-Key header and requestId body field must match. |
| 400 | `INVALID_REQUEST_ID` | Supply a UUID v4 requestId or Idempotency-Key. |
| 400 | `VALIDATION_ERROR` | The input does not match the action schema; inspect details for field errors. |
| 401 | `API_KEY_EXPIRED` | The API key has expired. |
| 401 | `INVALID_API_KEY` | Provide a valid, unexpired API key. |
| 401 | `INVALID_CREDENTIAL` | The Authorization header is malformed or conflicts with x-api-key. |
| 401 | `MISSING_CREDENTIAL` | No usable header credential was supplied, or it exceeded 4096 characters. |
| 401 | `USER_NOT_FOUND` | The credential's account no longer exists. |
| 403 | `ACCOUNT_UNAVAILABLE` | The acting or billing account is unavailable or being deleted. |
| 403 | `AMBIGUOUS_TEAM_API_KEY` | The credential's user belongs to more than one team, so the billing context is ambiguous. |
| 403 | `INSUFFICIENT_SCOPE` | Grant every required permission or choose another credential. |
| 403 | `INTEGRATION_PLAN_UNSUPPORTED` | The account's integration limits could not be verified. |
| 403 | `SUBSCRIPTION_REQUIRED` | Use an active paid subscription. |
| 403 | `TEAM_OWNER_NOT_FOUND` | The effective team owner account could not be found. |
| 404 | `USER_NOT_FOUND` | The authenticated account no longer exists. |
| 404 | `VOICE_PREVIEW_NOT_FOUND` | The request belongs to another account. |
| 409 | `CONCURRENT_ACTION_LIMIT_REACHED` | This account already has 10 integration actions running. Poll an existing request before starting another. |
| 409 | `IDEMPOTENCY_CONFLICT` | Reuse an identifier only with the same operation and arguments. |
| 409 | `VOICE_CREATION_IN_PROGRESS` | The preview is still being created or account deletion blocks new voice work. |
| 409 | `VOICE_CREATION_REQUEST_MISMATCH` | This requestId was used for a different voice kind or different settings or samples. |
| 409 | `VOICE_DESIGN_LIMIT_REACHED` | The daily voice design allowance is exhausted. |
| 410 | `VOICE_PREVIEW_EXPIRED` | The request’s voice preview is expired or no longer available. |
| 429 | `INTEGRATION_MONTHLY_LIMIT_REACHED` | Wait for the monthly reset or change plan. |
| 429 | `INTEGRATION_RATE_LIMIT_REACHED` | Wait for Retry-After when present and use backoff. |
| 500 | `INTERNAL_ERROR` | Check saved request state and resource history before deciding to retry a mutation. |
| 502 | `INTERNAL_ERROR` | The action could not be completed or its outcome could not be confirmed. Inspect request status and resource history before starting another generation. |
| 503 | `ACTION_RESULT_UNAVAILABLE` | The action ran but its result could not be saved. Inspect saved request state and resource history before starting a new generation. |
| 503 | `SERVER_RESTARTING` | The server is restarting. Retry shortly and keep the same request identifier for a mutation. |
```json theme={null}
{
"code": "INSUFFICIENT_SCOPE",
"message": "This credential does not permit the requested action.",
"status": 403,
"details": {
"requiredScopes": ["voices:write"]
}
}
```
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