> ## 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.
# Add a target language
> Add an empty target-language work to an existing project without starting paid media generation.
Add an empty target-language work to an existing project without starting paid media generation.
```http theme={null}
POST https://api.voicecheap.ai/v1/actions/translations_add
```
## 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: `translations:write`.
An active paid subscription is required. Permissions do not change team roles, resource ownership, media credits, or plan limits.
## Parameters
Text value.
Minimum length: 1. Maximum length: 200. Pattern: `^[^/\\]+$`.
Text value.
Allowed values: "afrikaans", "albanian", "amharic", "arabic", "armenian", "assamese", "azerbaijani", "basque", "belarusian", "bengali", "bosnian", "bulgarian", "catalan", "croatian", "czech", "danish", "dutch", "english", "british english", "estonian", "finnish", "french", "french canadian", "galician", "german", "greek", "gujarati", "hebrew", "hindi", "hungarian", "icelandic", "indonesian", "irish", "italian", "japanese", "kannada", "kazakh", "khmer", "korean", "lao", "latvian", "lithuanian", "macedonian", "malay", "malayalam", "mandarin", "marathi", "mongolian", "nepali", "norwegian", "persian", "polish", "portuguese", "brazilian portuguese", "pt\_brazil", "punjabi", "romanian", "russian", "serbian", "slovak", "slovenian", "spanish", "swahili", "swedish", "tagalog", "tamil", "telugu", "thai", "turkish", "ukrainian", "urdu", "vietnamese", "welsh", "yoruba", "zulu".
Optional at the transport boundary: the server injects an identifier before validation when omitted. Supply your own stable UUID v4 to recover safely from a lost response.
Format: "uuid". Pattern: `^[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-4[0-9a-fA-F]{3}-[89abAB][0-9a-fA-F]{3}-[0-9a-fA-F]{12}$`.
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": {
"projectId": {
"type": "string",
"minLength": 1,
"maxLength": 200,
"pattern": "^[^/\\\\]+$"
},
"targetLanguage": {
"type": "string",
"enum": [
"afrikaans",
"albanian",
"amharic",
"arabic",
"armenian",
"assamese",
"azerbaijani",
"basque",
"belarusian",
"bengali",
"bosnian",
"bulgarian",
"catalan",
"croatian",
"czech",
"danish",
"dutch",
"english",
"british english",
"estonian",
"finnish",
"french",
"french canadian",
"galician",
"german",
"greek",
"gujarati",
"hebrew",
"hindi",
"hungarian",
"icelandic",
"indonesian",
"irish",
"italian",
"japanese",
"kannada",
"kazakh",
"khmer",
"korean",
"lao",
"latvian",
"lithuanian",
"macedonian",
"malay",
"malayalam",
"mandarin",
"marathi",
"mongolian",
"nepali",
"norwegian",
"persian",
"polish",
"portuguese",
"brazilian portuguese",
"pt_brazil",
"punjabi",
"romanian",
"russian",
"serbian",
"slovak",
"slovenian",
"spanish",
"swahili",
"swedish",
"tagalog",
"tamil",
"telugu",
"thai",
"turkish",
"ukrainian",
"urdu",
"vietnamese",
"welsh",
"yoruba",
"zulu"
]
},
"requestId": {
"type": "string",
"format": "uuid",
"pattern": "^[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-4[0-9a-fA-F]{3}-[89abAB][0-9a-fA-F]{3}-[0-9a-fA-F]{12}$",
"description": "UUID v4 for this action. Reuse the same ID with identical arguments on retries."
}
},
"required": ["projectId", "targetLanguage"],
"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/translations_add' \
--header "x-api-key: $VOICECHEAP_API_KEY" \
--header 'Content-Type: application/json' \
--data '{"projectId":"project_launch_2026","targetLanguage":"english","requestId":"41321bda-e243-4b6f-96a4-622cd047c991"}'
```
```javascript JavaScript theme={null}
const input = {
projectId: 'project_launch_2026',
targetLanguage: 'english',
requestId: '41321bda-e243-4b6f-96a4-622cd047c991',
};
const response = await fetch('https://api.voicecheap.ai/v1/actions/translations_add', {
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/translations_add",
headers={"x-api-key": os.environ["VOICECHEAP_API_KEY"]},
json={"projectId": "project_launch_2026", "targetLanguage": "english", "requestId": "41321bda-e243-4b6f-96a4-622cd047c991"},
timeout=120,
)
body = response.json()
if not response.ok:
raise RuntimeError(f"{body.get('code')}: {body.get('message')}")
print(body)
```
## Response
A successful first execution returns HTTP 200 with the operation result under data. A replay may return saved request state instead. The example shows one supported response, not every optional field.
Returns a new language-work identity, or the full existing work projection when that target language already exists.
```json HTTP 200 theme={null}
{
"data": {
"projectId": "project_launch_2026",
"workId": "5f8423d1-e4c0-4f80-9e3f-eed959389e24",
"targetLanguage": "english"
},
"requestId": "41321bda-e243-4b6f-96a4-622cd047c991"
}
```
```json HTTP 202 replay_running theme={null}
{
"data": {
"requestId": "41321bda-e243-4b6f-96a4-622cd047c991",
"operation": "translations_add",
"createdAt": 1792144800000,
"updatedAt": 1792144820000,
"status": "running",
"pollAfterSeconds": 5
},
"requestId": "41321bda-e243-4b6f-96a4-622cd047c991"
}
```
```json HTTP 200 replay_completed_without_result theme={null}
{
"data": {
"requestId": "41321bda-e243-4b6f-96a4-622cd047c991",
"operation": "translations_add",
"createdAt": 1792144800000,
"updatedAt": 1792144820000,
"status": "completed",
"resultStored": false,
"message": "The action completed. Retrieve its output from the corresponding history or resource action."
},
"requestId": "41321bda-e243-4b6f-96a4-622cd047c991"
}
```
## Result fields
| Field | Description |
| - | - |
| `data.workId` | Language-work identifier. |
| `data.projectId` | Parent project identifier. |
| `data.targetLanguage` | Target language. |
| `data.originalLanguage` | Source language. |
| `data.createdAt` | Language-work creation time normalized to Unix milliseconds. |
| `data.isWorkWaitingForProofreading` | Proofreading state; false when not explicitly set. |
| `data.pendingSegmentIndexes` | Source segment indexes still pending translation, default empty array. |
| `data.versions` | All public versions in this work, sorted newest first. |
| `data.versions[].workId` | Language-work identifier containing this version. |
| `data.versions[].translatedVersionId` | Identifier for a particular dubbing output version. |
| `data.versions[].targetLanguage` | The version target language, falling back to its language work. |
| `data.versions[].status` | Stored version state: not-started, in-progress, completed, or failed. |
| `data.versions[].currentStep` | Optional dubbing pipeline step; progress is an optional numeric progress value. |
| `data.versions[].progress` | Optional dubbing progress value. |
| `data.versions[].createdAt` | Creation time normalized to Unix milliseconds; falls back to language-work creation time. |
| `data.versions[].completedAt` | Optional completion time in Unix milliseconds. |
| `data.versions[].failedAt` | Optional failure time in Unix milliseconds. |
| `data.versions[].timedOutAt` | Optional timeout time in Unix milliseconds. |
| `data.versions[].translatedVideoUrl` | Stored translated video URL, or an empty string when unavailable. |
| `data.versions[].translatedAudioUrl` | Stored translated audio URL, or an empty string when unavailable. |
| `data.versions[].error` | Optional \{code,message} when the version failed. |
| `data.versions[].settings` | Public version settings: voiceCloning, uploadType, keepBackgroundMusic, keepOriginalVoice, originalVoiceVolume, subtitles, smartSync, dubbingMode, voiceIsolatorOption, and optional translationQualityMode, cutBecauseFreeUser, originalDurationSeconds, cutDurationSeconds, voiceCloningSettings. |
| `data.versions[].settings.dubbingMode` | translate or dub-only. SmartSync is false for dub-only versions. |
| `data.versions[].lipSync` | Optional \{latest,history}; each entry has jobId, status, videoUrl, errorMessage, type, createdAt, and optional requestedAt, retryRequestedAt, completedAt, failedAt, timedOutAt, activeSpeakerDetectionEnabled, isRetried. Lip-sync times are stored ISO strings. |
| `data.versions[].dynamicSubtitles` | Optional object with used, inProgress, magicZooms, magicBrolls, magicBrollsPercentage, videoUrl, errorMessage, and optional removeSilencePace, removeBadTakes, templateName, requestedAt, rerunCount. requestedAt is Unix milliseconds. |
| `data.versions[].publicationAttempts` | Optional array of public publication attempts: id, status, origin, plus optional scheduledAt, processingStartedAt, publishedAt, failedAt, privacyStatus, url, videoId, errorMessage. |
| `data.versions[].publishedVideos` | Optional array with type, videoId, privacyStatus and optional url, datePublished, origin, scheduledAt, plannedPublicationId. |
## The target language already has a work in this project.
Returns the full existing language-work projection; no additional work is created.
```json HTTP 200 theme={null}
{
"data": {
"workId": "5f8423d1-e4c0-4f80-9e3f-eed959389e24",
"projectId": "project_launch_2026",
"targetLanguage": "english",
"originalLanguage": "fr",
"createdAt": 1792152000000,
"isWorkWaitingForProofreading": true,
"pendingSegmentIndexes": [0, 1],
"versions": []
}
}
```
## 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":"41321bda-e243-4b6f-96a4-622cd047c991","operation":"translations_add"}'
```
```json HTTP 200 theme={null}
{
"data": {
"requestId": "41321bda-e243-4b6f-96a4-622cd047c991",
"operation": "translations_add",
"status": "completed",
"createdAt": 1792144800000,
"updatedAt": 1792144820000,
"resultStored": true,
"result": {
"projectId": "project_launch_2026",
"workId": "5f8423d1-e4c0-4f80-9e3f-eed959389e24",
"targetLanguage": "english"
}
}
}
```
## Operation notes
* Adding a new language does not start transcription, translation or speech generation. The new work waits for proofreading and begins with all source segment indexes pending.
* The new-work branch returns exactly projectId, workId and targetLanguage. The existing-work branch returns the same projection as translations\_get.
* Start actual media processing separately with translations\_start or translations\_dub.
* Stored failures return VoiceCheap error codes and fixed messages. Use the code and current resource state to decide how to recover.
## 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` | Correct the input using the schema. Invalid or inconsistent values are rejected before execution. |
| 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 | `FORBIDDEN` | The authenticated actor cannot access this project. |
| 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 | `PROJECT_NOT_FOUND` | The project does not exist in the accessible 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. |
| 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. |
| 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": ["translations:write"]
}
}
```
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