curl --request POST 'https://api.voicecheap.ai/v1/actions/tts_generate' \
--header "x-api-key: $VOICECHEAP_API_KEY" \
--header 'Content-Type: application/json' \
--data '{"requestId":"284a861a-4da8-4d67-ad48-8123e76c8e91","text":"Hello world.","voice":"933563129e564b19a115bedd57b7406a","inputType":"text","instructionPreset":"narrator","instructions":"Speak clearly and leave a short pause at the end.","speed":1,"sourceFileName":"launch-script.txt"}'
const input = {
requestId: '284a861a-4da8-4d67-ad48-8123e76c8e91',
text: 'Hello world.',
voice: '933563129e564b19a115bedd57b7406a',
inputType: 'text',
instructionPreset: 'narrator',
instructions: 'Speak clearly and leave a short pause at the end.',
speed: 1,
sourceFileName: 'launch-script.txt',
};
const response = await fetch('https://api.voicecheap.ai/v1/actions/tts_generate', {
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);
import os
import requests
response = requests.post(
"https://api.voicecheap.ai/v1/actions/tts_generate",
headers={"x-api-key": os.environ["VOICECHEAP_API_KEY"]},
json={"requestId": "284a861a-4da8-4d67-ad48-8123e76c8e91", "text": "Hello world.", "voice": "933563129e564b19a115bedd57b7406a", "inputType": "text", "instructionPreset": "narrator", "instructions": "Speak clearly and leave a short pause at the end.", "speed": 1, "sourceFileName": "launch-script.txt"},
timeout=120,
)
body = response.json()
if not response.ok:
raise RuntimeError(f"{body.get('code')}: {body.get('message')}")
print(body)
{
"data": {
"requestId": "284a861a-4da8-4d67-ad48-8123e76c8e91",
"status": "running",
"pollAction": "action_request_get",
"pollAfterSeconds": 5
},
"requestId": "284a861a-4da8-4d67-ad48-8123e76c8e91"
}
{
"data": {
"requestId": "284a861a-4da8-4d67-ad48-8123e76c8e91",
"historyId": "722c80c6412edd4c3dcd625061e1c1feafbb0d54274d95fd8b5ca047f8cdd23d",
"status": "completed",
"characterCount": 12,
"previewEndIndex": null,
"downloadUrl": "https://files.example.com/launch-script-speech.mp3"
},
"requestId": "284a861a-4da8-4d67-ad48-8123e76c8e91"
}
{
"data": {
"requestId": "284a861a-4da8-4d67-ad48-8123e76c8e91",
"operation": "tts_generate",
"createdAt": 1792144800000,
"updatedAt": 1792144820000,
"status": "running",
"pollAfterSeconds": 5
},
"requestId": "284a861a-4da8-4d67-ad48-8123e76c8e91"
}
{
"data": {
"requestId": "284a861a-4da8-4d67-ad48-8123e76c8e91",
"operation": "tts_generate",
"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"
}
Text to speech
Generate speech
Create speech from text using a catalog or owned custom voice. Uses the same character credits and plan limits as the app. Returns a history ID and a temporary audio download URL. Reuse requestId to avoid a second generation.
POST
/
v1
/
actions
/
tts_generate
curl --request POST 'https://api.voicecheap.ai/v1/actions/tts_generate' \
--header "x-api-key: $VOICECHEAP_API_KEY" \
--header 'Content-Type: application/json' \
--data '{"requestId":"284a861a-4da8-4d67-ad48-8123e76c8e91","text":"Hello world.","voice":"933563129e564b19a115bedd57b7406a","inputType":"text","instructionPreset":"narrator","instructions":"Speak clearly and leave a short pause at the end.","speed":1,"sourceFileName":"launch-script.txt"}'
const input = {
requestId: '284a861a-4da8-4d67-ad48-8123e76c8e91',
text: 'Hello world.',
voice: '933563129e564b19a115bedd57b7406a',
inputType: 'text',
instructionPreset: 'narrator',
instructions: 'Speak clearly and leave a short pause at the end.',
speed: 1,
sourceFileName: 'launch-script.txt',
};
const response = await fetch('https://api.voicecheap.ai/v1/actions/tts_generate', {
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);
import os
import requests
response = requests.post(
"https://api.voicecheap.ai/v1/actions/tts_generate",
headers={"x-api-key": os.environ["VOICECHEAP_API_KEY"]},
json={"requestId": "284a861a-4da8-4d67-ad48-8123e76c8e91", "text": "Hello world.", "voice": "933563129e564b19a115bedd57b7406a", "inputType": "text", "instructionPreset": "narrator", "instructions": "Speak clearly and leave a short pause at the end.", "speed": 1, "sourceFileName": "launch-script.txt"},
timeout=120,
)
body = response.json()
if not response.ok:
raise RuntimeError(f"{body.get('code')}: {body.get('message')}")
print(body)
{
"data": {
"requestId": "284a861a-4da8-4d67-ad48-8123e76c8e91",
"status": "running",
"pollAction": "action_request_get",
"pollAfterSeconds": 5
},
"requestId": "284a861a-4da8-4d67-ad48-8123e76c8e91"
}
{
"data": {
"requestId": "284a861a-4da8-4d67-ad48-8123e76c8e91",
"historyId": "722c80c6412edd4c3dcd625061e1c1feafbb0d54274d95fd8b5ca047f8cdd23d",
"status": "completed",
"characterCount": 12,
"previewEndIndex": null,
"downloadUrl": "https://files.example.com/launch-script-speech.mp3"
},
"requestId": "284a861a-4da8-4d67-ad48-8123e76c8e91"
}
{
"data": {
"requestId": "284a861a-4da8-4d67-ad48-8123e76c8e91",
"operation": "tts_generate",
"createdAt": 1792144800000,
"updatedAt": 1792144820000,
"status": "running",
"pollAfterSeconds": 5
},
"requestId": "284a861a-4da8-4d67-ad48-8123e76c8e91"
}
{
"data": {
"requestId": "284a861a-4da8-4d67-ad48-8123e76c8e91",
"operation": "tts_generate",
"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"
}
Create speech from text using a catalog or owned custom voice. Uses the same character credits and plan limits as the app. Returns a history ID and a temporary audio download URL. Reuse requestId to avoid a second generation.
Required permissions:
POST https://api.voicecheap.ai/v1/actions/tts_generate
Authentication and permissions
string
required
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.
tts:write.
An active paid subscription is required. Permissions do not change team roles, resource ownership, media credits, or plan limits.
Parameters
string
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}$.string
required
Text value.Minimum length: 1. Maximum length: 128000.
string
required
A voice selection ID from voices_list, including clone: IDs for saved custom voices.Minimum length: 1. Maximum length: 255.
string
Text value.Allowed values: “text”, “pdf”. Default: “text”.
string
Text value.Allowed values: “default”, “cheerful”, “calm”, “narrator”, “dramatic”, “whisper”, “energetic”. Default: “default”.
string
Text value.Maximum length: 300.
number
Numeric value.Minimum: 0.5. Maximum: 2. Default: 1.
string
Text value.Maximum length: 255.
Complete input schema
Complete input schema
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.
{
"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}$"
},
"text": {
"type": "string",
"minLength": 1,
"maxLength": 128000
},
"voice": {
"type": "string",
"minLength": 1,
"maxLength": 255,
"description": "A voice selection ID from voices_list, including clone: IDs for saved custom voices."
},
"inputType": {
"default": "text",
"type": "string",
"enum": ["text", "pdf"]
},
"instructionPreset": {
"default": "default",
"type": "string",
"enum": ["default", "cheerful", "calm", "narrator", "dramatic", "whisper", "energetic"]
},
"instructions": {
"type": "string",
"maxLength": 300
},
"speed": {
"default": 1,
"type": "number",
"minimum": 0.5,
"maximum": 2
},
"sourceFileName": {
"type": "string",
"maxLength": 255
}
},
"required": ["text", "voice"],
"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.curl --request POST 'https://api.voicecheap.ai/v1/actions/tts_generate' \
--header "x-api-key: $VOICECHEAP_API_KEY" \
--header 'Content-Type: application/json' \
--data '{"requestId":"284a861a-4da8-4d67-ad48-8123e76c8e91","text":"Hello world.","voice":"933563129e564b19a115bedd57b7406a","inputType":"text","instructionPreset":"narrator","instructions":"Speak clearly and leave a short pause at the end.","speed":1,"sourceFileName":"launch-script.txt"}'
const input = {
requestId: '284a861a-4da8-4d67-ad48-8123e76c8e91',
text: 'Hello world.',
voice: '933563129e564b19a115bedd57b7406a',
inputType: 'text',
instructionPreset: 'narrator',
instructions: 'Speak clearly and leave a short pause at the end.',
speed: 1,
sourceFileName: 'launch-script.txt',
};
const response = await fetch('https://api.voicecheap.ai/v1/actions/tts_generate', {
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);
import os
import requests
response = requests.post(
"https://api.voicecheap.ai/v1/actions/tts_generate",
headers={"x-api-key": os.environ["VOICECHEAP_API_KEY"]},
json={"requestId": "284a861a-4da8-4d67-ad48-8123e76c8e91", "text": "Hello world.", "voice": "933563129e564b19a115bedd57b7406a", "inputType": "text", "instructionPreset": "narrator", "instructions": "Speak clearly and leave a short pause at the end.", "speed": 1, "sourceFileName": "launch-script.txt"},
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. Completed speech generation metadata and a temporary MP3 download URL. The handler does not return audio bytes.{
"data": {
"requestId": "284a861a-4da8-4d67-ad48-8123e76c8e91",
"status": "running",
"pollAction": "action_request_get",
"pollAfterSeconds": 5
},
"requestId": "284a861a-4da8-4d67-ad48-8123e76c8e91"
}
{
"data": {
"requestId": "284a861a-4da8-4d67-ad48-8123e76c8e91",
"historyId": "722c80c6412edd4c3dcd625061e1c1feafbb0d54274d95fd8b5ca047f8cdd23d",
"status": "completed",
"characterCount": 12,
"previewEndIndex": null,
"downloadUrl": "https://files.example.com/launch-script-speech.mp3"
},
"requestId": "284a861a-4da8-4d67-ad48-8123e76c8e91"
}
{
"data": {
"requestId": "284a861a-4da8-4d67-ad48-8123e76c8e91",
"operation": "tts_generate",
"createdAt": 1792144800000,
"updatedAt": 1792144820000,
"status": "running",
"pollAfterSeconds": 5
},
"requestId": "284a861a-4da8-4d67-ad48-8123e76c8e91"
}
{
"data": {
"requestId": "284a861a-4da8-4d67-ad48-8123e76c8e91",
"operation": "tts_generate",
"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.requestId | UUID v4 supplied for the generation action. |
data.historyId | Owned speech history ID: 64 lowercase hexadecimal characters, optionally prefixed with free- for an app preview. |
data.status | completed when the speech result is ready. |
data.characterCount | Number of characters in the full trimmed input text. |
data.previewEndIndex | Character boundary of partial preview audio, or null for complete audio. Paid integration generation returns complete audio. |
data.downloadUrl | Temporary MP3 download URL. Request a fresh one through tts_download. |
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.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":"tts_generate"}'
HTTP 200
{
"data": {
"requestId": "284a861a-4da8-4d67-ad48-8123e76c8e91",
"operation": "tts_generate",
"status": "completed",
"createdAt": 1792144800000,
"updatedAt": 1792144820000,
"resultStored": true,
"result": {
"requestId": "284a861a-4da8-4d67-ad48-8123e76c8e91",
"historyId": "722c80c6412edd4c3dcd625061e1c1feafbb0d54274d95fd8b5ca047f8cdd23d",
"status": "completed",
"characterCount": 12,
"previewEndIndex": null,
"downloadUrl": "https://files.example.com/launch-script-speech.mp3"
}
}
}
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.
- Choose voice from voices_list. Dubbing voice IDs from dubbing_voices_list are a separate library.
- Text is trimmed. The schema accepts at most 128,000 characters; current Beginner and Starter plans allow 64,000 per generation, while Creator and higher plans allow 128,000. The current plan and available TTS character credits are checked again before generation.
- inputType defaults to text and can be text or pdf. Even with pdf, supply extracted text in text; this action does not accept a PDF upload or URL.
- instructionPreset defaults to default and supports default, cheerful, calm, narrator, dramatic, whisper, and energetic. instructions is optional and limited to 300 trimmed characters. speed defaults to 1 and ranges from 0.5 to 2.
- sourceFileName is optional metadata, limited to 255 trimmed characters, and determines the download filename.
- A successful repeated request replays saved audio without generating or charging for it again. URLs are temporary; use tts_download for a fresh download.
- 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 | INVALID_VOICE | The voice selection is invalid, is not owned by this account, or is not ready. |
| 400 | TEXT_REQUIRED | The script is empty after removing delivery control tags. |
| 400 | TEXT_TOO_LONG | The script exceeds the current plan’s per-generation character limit. |
| 400 | VALIDATION_ERROR | The input does not match the action schema; inspect details for field errors. |
| 400 | VOICE_UNAVAILABLE | The selected catalog voice is no longer available; choose an ID returned by voices_list. |
| 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 | PAID_PLAN_REQUIRED | The current account no longer has a paid plan for integration speech generation. |
| 403 | SUBSCRIPTION_REQUIRED | Use an active paid subscription. |
| 403 | TEAM_OWNER_NOT_FOUND | The effective team owner account could not be found. |
| 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 | TEXT_TO_SPEECH_GENERATION_IN_PROGRESS | An identical speech request is still processing. |
| 409 | TEXT_TO_SPEECH_REQUEST_CONFLICT | This requestId was already used with different speech input. |
| 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. |
| 429 | TEXT_TO_SPEECH_CHARACTER_LIMIT_REACHED | The script exceeds the combined included and purchased TTS characters available. |
| 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. |
{
"code": "INSUFFICIENT_SCOPE",
"message": "This credential does not permit the requested action.",
"status": 403,
"details": {
"requiredScopes": ["tts:write"]
}
}
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