> ## 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. # Complete a speech preview > Generate the rest of an owned speech preview when the current account has access. Repeated calls replay the completed audio without new character charges. Generate the rest of an owned speech preview when the current account has access. Repeated calls replay the completed audio without new character charges. ```http theme={null} POST https://api.voicecheap.ai/v1/actions/tts_continue ``` ## 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: `tts: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}$`. History ID returned by tts\_generate or tts\_list. Pattern: `^(free-)?[0-9a-f]{64}$`. 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}$" }, "historyId": { "type": "string", "pattern": "^(free-)?[0-9a-f]{64}$", "description": "History ID returned by tts_generate or tts_list." } }, "required": ["historyId"], "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/tts_continue' \ --header "x-api-key: $VOICECHEAP_API_KEY" \ --header 'Content-Type: application/json' \ --data '{"requestId":"284a861a-4da8-4d67-ad48-8123e76c8e91","historyId":"free-ebdb6d6f77433edf7c0169994cdce394f1c9c366e4d98cd4762a037cadea0ae4"}' ``` ```javascript JavaScript theme={null} const input = { requestId: '284a861a-4da8-4d67-ad48-8123e76c8e91', historyId: 'free-ebdb6d6f77433edf7c0169994cdce394f1c9c366e4d98cd4762a037cadea0ae4', }; const response = await fetch('https://api.voicecheap.ai/v1/actions/tts_continue', { 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/tts_continue", headers={"x-api-key": os.environ["VOICECHEAP_API_KEY"]}, json={"requestId": "284a861a-4da8-4d67-ad48-8123e76c8e91", "historyId": "free-ebdb6d6f77433edf7c0169994cdce394f1c9c366e4d98cd4762a037cadea0ae4"}, 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 metadata for the full audio of an owned app preview. The original historyId is retained. ```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": { "requestId": "284a861a-4da8-4d67-ad48-8123e76c8e91", "historyId": "free-ebdb6d6f77433edf7c0169994cdce394f1c9c366e4d98cd4762a037cadea0ae4", "status": "completed", "characterCount": 12, "previewEndIndex": null, "downloadUrl": "https://files.example.com/completed-preview-speech.mp3" }, "requestId": "284a861a-4da8-4d67-ad48-8123e76c8e91" } ``` ```json HTTP 202 replay_running theme={null} { "data": { "requestId": "284a861a-4da8-4d67-ad48-8123e76c8e91", "operation": "tts_continue", "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": "tts_continue", "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. ```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":"tts_continue"}' ``` ```json HTTP 200 theme={null} { "data": { "requestId": "284a861a-4da8-4d67-ad48-8123e76c8e91", "operation": "tts_continue", "status": "completed", "createdAt": 1792144800000, "updatedAt": 1792144820000, "resultStored": true, "result": { "requestId": "284a861a-4da8-4d67-ad48-8123e76c8e91", "historyId": "free-ebdb6d6f77433edf7c0169994cdce394f1c9c366e4d98cd4762a037cadea0ae4", "status": "completed", "characterCount": 12, "previewEndIndex": null, "downloadUrl": "https://files.example.com/completed-preview-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. * Use an existing owned preview historyId from the app or tts\_list after upgrading. This action cannot create a new free preview. * The remaining script counts against the current TTS character allowance. Repeated completion of the same preview reuses the completed audio without spending those characters again. * If the item is already complete, its current audio is returned. The result characterCount describes the full original script and previewEndIndex is null once unlocked. * 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 | `PAID_PLAN_REQUIRED` | A paid plan is required for integration speech generation, including completion of app previews. | | 403 | `SUBSCRIPTION_REQUIRED` | Use an active paid subscription. | | 403 | `TEAM_OWNER_NOT_FOUND` | The effective team owner account could not be found. | | 404 | `TEXT_TO_SPEECH_HISTORY_NOT_FOUND` | The speech history item does not exist or 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 | `TEXT_TO_SPEECH_GENERATION_IN_PROGRESS` | The preview completion is still running. | | 409 | `TEXT_TO_SPEECH_REQUEST_CONFLICT` | The underlying preview completion request conflicts with stored 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` | There are not enough included and purchased TTS characters for the remaining script. | | 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": ["tts:write"] } } ``` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.