Initialize a thumbnail reference upload

curl --request POST 'https://api.voicecheap.ai/v1/actions/thumbnails_upload_initialize' \
  --header "x-api-key: $VOICECHEAP_API_KEY" \
  --header 'Content-Type: application/json' \
  --data '{"requestId":"19372a86-ee2f-4c6d-835b-ec1b10b7c68b","filename":"reference.png","contentType":"image/png","fileSize":7340032}'

const input = {
  requestId: '19372a86-ee2f-4c6d-835b-ec1b10b7c68b',
  filename: 'reference.png',
  contentType: 'image/png',
  fileSize: 7340032,
};
const response = await fetch('https://api.voicecheap.ai/v1/actions/thumbnails_upload_initialize', {
  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/thumbnails_upload_initialize",
    headers={"x-api-key": os.environ["VOICECHEAP_API_KEY"]},
    json={"requestId": "19372a86-ee2f-4c6d-835b-ec1b10b7c68b", "filename": "reference.png", "contentType": "image/png", "fileSize": 7340032},
    timeout=120,
)
body = response.json()
if not response.ok:
    raise RuntimeError(f"{body.get('code')}: {body.get('message')}")
print(body)

{
  "data": {
    "uploadId": "c547fb7f-f334-46a8-a8bb-80b5b343889a",
    "key": "uploads/example-user/2502829e-3fde-4aad-b3c7-ce0f779fa2e6-reference.png",
    "partSize": 5242880,
    "maxConcurrency": 4
  },
  "requestId": "19372a86-ee2f-4c6d-835b-ec1b10b7c68b"
}

{
  "data": {
    "requestId": "19372a86-ee2f-4c6d-835b-ec1b10b7c68b",
    "operation": "thumbnails_upload_initialize",
    "createdAt": 1792144800000,
    "updatedAt": 1792144820000,
    "status": "running",
    "pollAfterSeconds": 5
  },
  "requestId": "19372a86-ee2f-4c6d-835b-ec1b10b7c68b"
}

{
  "data": {
    "requestId": "19372a86-ee2f-4c6d-835b-ec1b10b7c68b",
    "operation": "thumbnails_upload_initialize",
    "createdAt": 1792144800000,
    "updatedAt": 1792144820000,
    "status": "completed",
    "resultStored": false,
    "message": "The action completed. Retrieve its output from the corresponding history or resource action."
  },
  "requestId": "19372a86-ee2f-4c6d-835b-ec1b10b7c68b"
}

POST

actions

thumbnails_upload_initialize

curl --request POST 'https://api.voicecheap.ai/v1/actions/thumbnails_upload_initialize' \
  --header "x-api-key: $VOICECHEAP_API_KEY" \
  --header 'Content-Type: application/json' \
  --data '{"requestId":"19372a86-ee2f-4c6d-835b-ec1b10b7c68b","filename":"reference.png","contentType":"image/png","fileSize":7340032}'

const input = {
  requestId: '19372a86-ee2f-4c6d-835b-ec1b10b7c68b',
  filename: 'reference.png',
  contentType: 'image/png',
  fileSize: 7340032,
};
const response = await fetch('https://api.voicecheap.ai/v1/actions/thumbnails_upload_initialize', {
  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/thumbnails_upload_initialize",
    headers={"x-api-key": os.environ["VOICECHEAP_API_KEY"]},
    json={"requestId": "19372a86-ee2f-4c6d-835b-ec1b10b7c68b", "filename": "reference.png", "contentType": "image/png", "fileSize": 7340032},
    timeout=120,
)
body = response.json()
if not response.ok:
    raise RuntimeError(f"{body.get('code')}: {body.get('message')}")
print(body)

{
  "data": {
    "uploadId": "c547fb7f-f334-46a8-a8bb-80b5b343889a",
    "key": "uploads/example-user/2502829e-3fde-4aad-b3c7-ce0f779fa2e6-reference.png",
    "partSize": 5242880,
    "maxConcurrency": 4
  },
  "requestId": "19372a86-ee2f-4c6d-835b-ec1b10b7c68b"
}

{
  "data": {
    "requestId": "19372a86-ee2f-4c6d-835b-ec1b10b7c68b",
    "operation": "thumbnails_upload_initialize",
    "createdAt": 1792144800000,
    "updatedAt": 1792144820000,
    "status": "running",
    "pollAfterSeconds": 5
  },
  "requestId": "19372a86-ee2f-4c6d-835b-ec1b10b7c68b"
}

{
  "data": {
    "requestId": "19372a86-ee2f-4c6d-835b-ec1b10b7c68b",
    "operation": "thumbnails_upload_initialize",
    "createdAt": 1792144800000,
    "updatedAt": 1792144820000,
    "status": "completed",
    "resultStored": false,
    "message": "The action completed. Retrieve its output from the corresponding history or resource action."
  },
  "requestId": "19372a86-ee2f-4c6d-835b-ec1b10b7c68b"
}

Prepare a JPG, PNG or WebP reference upload up to 8 MiB. Use thumbnails_upload_sign_parts to get PUT URLs, upload the bytes, then call thumbnails_upload_complete and use its fileKey when generating.

POST https://api.voicecheap.ai/v1/actions/thumbnails_upload_initialize

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.

Required permissions: thumbnails: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

The image filename, with an extension matching contentType.Minimum length: 1. Maximum length: 250. Pattern: \.(?:jpe?g|png|webp)$.

string

required

Text value.Allowed values: “image/jpeg”, “image/png”, “image/webp”.

integer

required

Exact file size in bytes, up to 8 MiB.Minimum: 1. Maximum: 8388608.

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}$"
    },
    "filename": {
      "type": "string",
      "minLength": 1,
      "maxLength": 250,
      "pattern": "\\.(?:jpe?g|png|webp)$",
      "description": "The image filename, with an extension matching contentType."
    },
    "contentType": {
      "type": "string",
      "enum": ["image/jpeg", "image/png", "image/webp"]
    },
    "fileSize": {
      "type": "integer",
      "minimum": 1,
      "maximum": 8388608,
      "description": "Exact file size in bytes, up to 8 MiB."
    }
  },
  "required": ["filename", "contentType", "fileSize"],
  "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/thumbnails_upload_initialize' \
  --header "x-api-key: $VOICECHEAP_API_KEY" \
  --header 'Content-Type: application/json' \
  --data '{"requestId":"19372a86-ee2f-4c6d-835b-ec1b10b7c68b","filename":"reference.png","contentType":"image/png","fileSize":7340032}'

const input = {
  requestId: '19372a86-ee2f-4c6d-835b-ec1b10b7c68b',
  filename: 'reference.png',
  contentType: 'image/png',
  fileSize: 7340032,
};
const response = await fetch('https://api.voicecheap.ai/v1/actions/thumbnails_upload_initialize', {
  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/thumbnails_upload_initialize",
    headers={"x-api-key": os.environ["VOICECHEAP_API_KEY"]},
    json={"requestId": "19372a86-ee2f-4c6d-835b-ec1b10b7c68b", "filename": "reference.png", "contentType": "image/png", "fileSize": 7340032},
    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. A new multipart image-reference upload session, the future object key, the part size in bytes, and the maximum parallel-upload count. This does not upload any image bytes or make key ready for generation.

{
  "data": {
    "uploadId": "c547fb7f-f334-46a8-a8bb-80b5b343889a",
    "key": "uploads/example-user/2502829e-3fde-4aad-b3c7-ce0f779fa2e6-reference.png",
    "partSize": 5242880,
    "maxConcurrency": 4
  },
  "requestId": "19372a86-ee2f-4c6d-835b-ec1b10b7c68b"
}

{
  "data": {
    "requestId": "19372a86-ee2f-4c6d-835b-ec1b10b7c68b",
    "operation": "thumbnails_upload_initialize",
    "createdAt": 1792144800000,
    "updatedAt": 1792144820000,
    "status": "running",
    "pollAfterSeconds": 5
  },
  "requestId": "19372a86-ee2f-4c6d-835b-ec1b10b7c68b"
}

{
  "data": {
    "requestId": "19372a86-ee2f-4c6d-835b-ec1b10b7c68b",
    "operation": "thumbnails_upload_initialize",
    "createdAt": 1792144800000,
    "updatedAt": 1792144820000,
    "status": "completed",
    "resultStored": false,
    "message": "The action completed. Retrieve its output from the corresponding history or resource action."
  },
  "requestId": "19372a86-ee2f-4c6d-835b-ec1b10b7c68b"
}

Result fields

Field	Description
`data.uploadId`	UUID identifying the active upload session. Pass it to the remaining upload actions.
`data.key`	Future owned object key. Use fileKey from a successful completion as the generation reference.
`data.partSize`	Required part size in bytes, except that the final part contains the remaining bytes.
`data.maxConcurrency`	Maximum suggested number of parallel part uploads: 4.

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":"19372a86-ee2f-4c6d-835b-ec1b10b7c68b","operation":"thumbnails_upload_initialize"}'

HTTP 200

{
  "data": {
    "requestId": "19372a86-ee2f-4c6d-835b-ec1b10b7c68b",
    "operation": "thumbnails_upload_initialize",
    "status": "completed",
    "createdAt": 1792144800000,
    "updatedAt": 1792144820000,
    "resultStored": true,
    "result": {
      "uploadId": "c547fb7f-f334-46a8-a8bb-80b5b343889a",
      "key": "uploads/example-user/2502829e-3fde-4aad-b3c7-ce0f779fa2e6-reference.png",
      "partSize": 5242880,
      "maxConcurrency": 4
    }
  }
}

Operation notes

Requires thumbnails:write; no additional upload scope is needed.
filename is trimmed, must contain 1–250 characters, and must end in .jpg, .jpeg, .png, or .webp. Its extension must match contentType: image/jpeg, image/png, or image/webp. fileSize is the exact integer byte count, from 1 to 8,388,608.
The shared upload implementation returns partSize 5 MiB (5,242,880 bytes) for these references. A file of at most 5 MiB uses one part; a larger file up to 8 MiB uses two. Request PUT URLs with thumbnails_upload_sign_parts, upload the bytes, then call thumbnails_upload_complete.
Use the fileKey returned by completion as an entry in referenceImageKeys in thumbnails_generate. The initialize result uses key, not fileKey. Do not pass key to generation before completion.
The production upload session expires after 24 hours. Signed part URLs expire after one hour. Completion and abort remove the active session; sign-parts and complete then return Upload not found. Neither response includes an expiresAt field.
This action uses the connected user’s own creations and uploads, including when the credential is connected in a team context.
Use a UUID v4 requestId, or the HTTP Idempotency-Key header, and reuse it with identical inputs when retrying. The integration layer records each mutation and returns its recorded state or result without rerunning it. A failed or interrupted request is not automatically retried.
The filename in the object key is sanitized and may be shortened. Keep the exact returned key and uploadId; do not construct them yourself. Image bytes are validated during generation as well as the declared size and type during upload.

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`	requestId or Idempotency-Key is not a UUID v4.
400	`REFERENCE_IMAGE_INVALID`	The filename extension does not match the declared image contentType.
400	`VALIDATION_ERROR`	An argument is missing, has an unsupported value, exceeds its limit, or is not part of the strict input schema.
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.
409	`CONCURRENT_ACTION_LIMIT_REACHED`	This account already has 10 integration actions running. Poll an existing request before starting another.
409	`IDEMPOTENCY_CONFLICT`	The request identifier was already used with different arguments; a header/body identifier mismatch returns HTTP 400 with the same code.
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	`INTERNAL_ERROR`	The upload session could not be created or saved. Retry the same mutation identifier and inspect its recorded state.
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": ["thumbnails:write"]
  }
}

Overview

Discovery

Account

Usage and activity

Settings and notifications

Team

Projects

Translation and dubbing

Transcripts and editing

Text to speech

Speech voices

Dubbing voices

Transcription

Subtitles and captions

Images

Thumbnails

Folders

Glossary

Webhooks

Publishing

Request status

OAuth and MCP protocol

Authentication and permissions

Parameters

Idempotency

Request examples

Response

Result fields

Recover and poll this request

Operation notes

Usage

Errors

​Authentication and permissions

​Parameters

​Idempotency

​Request examples

​Response

​Result fields

​Recover and poll this request

​Operation notes

​Usage

​Errors

Authentication and permissions

Parameters

Idempotency

Request examples

Response

Result fields

Recover and poll this request

Operation notes

Usage

Errors