Version: June 2025

Webhooks

We added webhooks to notify you about the status of a process initiated using one of our tools. This helps you automate workflows using our API.

Quick Start

Creating a new webhook endpoint is easy.

  1. Open the API page in your profile and navigate to "Webhooks".
  2. Click the "Create Webhook" button at the top.
  3. Enter a Name and the URL of your endpoint.
  4. Click "Test & Create"
  5. A first test will then be executed. Copy the secret for your endpoint script.

The first part is done. Now it's time to create the endpoint on your server. You can edit the URL or name of the endpoint at any time.

Whenever a process finishes or fails, a request will be sent to your server.

Tools

The following tools use webhooks to notify you about finished or failed processes:

  • Subtitle Translator
  • Subtitle Converter (Batch Processing)
  • Loudness Radar & Normalizer
  • Scene Cut Detection
  • Stills from Video

Webhook Payload Details

Each webhook request will include a JSON payload with the following fields:

  • event (string): The type of event that triggered the webhook. Currently, only "process" events are supported.
  • status (string): The current status of the process. Possible values are:
    • "finished": The process completed successfully.
    • "failed": The process encountered an error and could not be completed.
  • processId (string): A unique identifier for the initiated process. This ID can be used with the "Get Process Details" endpoint to retrieve more information or download files.

Webhook Payload Example (Finished)

When a process is successfully completed, it sends a request with the following content:

{
	"event": "process", 
	"status": "finished", 
	"processId": "#ABC123"
}

Webhook Payload Example (Failed)

If a process fails, it will generate a request similar to the following:

{
	"event": "process", 
	"status": "failed", 
	"processId": "#ABC123"
}

Signature Verification

To ensure the authenticity and integrity of the webhooks you receive, it's crucial to verify the signature included in the HTTP_EDITINGTOOLS_SIGNATURE header. This header contains a timestamp and a signature, separated by commas.

The signature is generated using an HMAC-SHA256 hash of the webhook payload and your unique endpoint secret. Verifying this signature protects your endpoint from unauthorized requests and ensures the data hasn't been tampered with.

How Signature Verification Works

  1. Extract Information: From the HTTP_EDITINGTOOLS_SIGNATURE header, extract the t (timestamp) and v1 (signature) values.
  2. Prepare the Signed Payload: Concatenate the timestamp (as a string) with a dot (.) and the raw JSON payload body. For example: t.payload_body.
  3. Compute Expected Signature: Calculate the HMAC-SHA256 hash of the signed payload using your endpoint secret as the key.
  4. Compare Signatures: Compare your computed signature with the v1 signature received in the header. If they match, the webhook is valid.

Webhook Endpoint Best Practices

To ensure reliable and secure webhook processing, consider the following best practices for your endpoint:

  • Respond Quickly: Your webhook endpoint should process the incoming request as quickly as possible and return an HTTP 200 OK response. Avoid performing long-running tasks directly within the webhook handler. Instead, queue these tasks for asynchronous processing.
  • Expected HTTP Responses:
    • HTTP 200 OK: Return a 200 OK status code if you successfully received and processed the webhook.
    • HTTP 4xx/5xx: If your endpoint encounters an error (e.g., invalid signature, server error), return an appropriate 4xx (client error) or 5xx (server error) status code.
  • Webhook Retries: If your endpoint does not return a 200 OK status code, we will not automatically retry the delivery of the webhook.
  • Logging: Implement robust logging for all incoming webhook requests, including the full request body and headers. This will be invaluable for debugging any issues.

Receive a webhook (example)

You can receive a webhook by creating a script similar to this PHP example. Make sure to replace the endpoint_secret.

// webhook.php
header('Content-Type: application/json');
$endpoint_secret = 'whsec_XXXXXXXXXXXXXXXXXXXXXXXXXXXX';
$payload = @file_get_contents('php://input');
$signature_header = $_SERVER['HTTP_EDITINGTOOLS_SIGNATURE'];
$timestamp = null;
$signature = null;

if (!$signature_header) {
http_response_code(400);
echo json_encode(['message' => 'Missing signature']);
exit();
}

// Parse Stripe-style signature header
foreach (explode(',', $signature_header) as $pair) {
    list($k, $v) = explode('=', $pair, 2);
    if ($k === 't') $timestamp = $v;
    if ($k === 'v1') $signature = $v;
}

$expected_signature = hash_hmac('sha256', $timestamp . '.' . $payload, $endpoint_secret);

if (!hash_equals($expected_signature, $signature)) {
    http_response_code(400);
    echo json_encode(['message' => 'Invalid signature']);
    exit;
}


$data = json_decode($payload, true);
// Process webhook data (customize to your event)
//file_put_contents('webhook_log.txt', print_r($data, true), FILE_APPEND);
// or enter it into your database...

http_response_code(200);
echo json_encode(['message' => 'Webhook received']);

Send a Test Request

To generate a test request, click the three dots on your webhook endpoint and select "Test Endpoint."

Get Processed Files

To receive and download the processed files, use the "Get Process Details" endpoint.

Authentication

This API requires Basic Authentication. The "Authorization" header should be set with the Base64 encoded string of "apikey:YOUR_API_KEY".

Authorization: Basic <base64Encoded(apikey:YOUR_API_KEY)>

Data Handling

Request parameters must be UTF-8 encoded. Results are returned as UTF-8-encoded JSON. By default, datasets will be inside the data tag.

Error Handling

This API service uses standard HTTP response codes to indicate whether a method was completed successfully. HTTP response codes in the 2XX range indicate success. Responses in the 4XX range indicate some sort of failure, while responses in the 5XX range indicate an internal system error that cannot be resolved by the user. The following error codes are used by the API:

Code Description
200 OK. The request was successful.
201 Created. The entity was created.
202 Accepted. The request was accepted.
400 Bad request. Please check error message.
401 Unauthorized: Username or Api Key is not valid.
402 Upgrade Required: This feature requires an active Pro subscription.
403 Forbidden: The request is understood, but it has been refused or access is not allowed.
404 Not found: The URI requested is invalid or the resource does not exist.
422 Unprocessable Entity. A process failed.
429 Too Many Requests. Try again in some seconds.
500 Internal Server Error. Something is broken.
502 Bad Gateway. API is down.
503 Service Unavailable. API is up but overloaded with requests.
504 Gateway Timeout: API is up but requests reached timout.

Rate Limits

To prevent abuse and spam, the API has limits at various levels. If you receive error code 429 (Too Many Requests), it means you have reached a rate limit.

If you receive a rate limit error, you should stop making requests temporarily. If the retry-after response header is present, you should not retry your request until after that many seconds has elapsed. To prevent rate-errors, we recommend to wait 300 ms to 800 ms between requests to the same endpoint.

Also there is a general limit to the api and all requests made:

Limit Requests
General limit per minute 50
General limit per hour 1000
Recommended wait time between requests > 200 ms
Recommended wait time between requests to one endpoint > 600 ms

The general limits per minute and per hour can be changed upon request.

Upload Limits

The maximum upload size for any single request — including file uploads — is 100 MB. This is a hard limit and applies regardless of your API plan or usage level.

If your request exceeds this size, it will be rejected before reaching our servers. To ensure successful uploads:

  • Make sure uploaded files are under 100 MB.
  • For larger media, consider splitting files before upload.
  • Requests close to the limit may still fail due to encoding or header overhead.

Timezone

This API endpoint returns the time as an ISO 8601 timestamp in the UTC time zone. These timestamps look like 2025-01-10T15:05:06Z.

Localization and Languages

This API supports multiple languages. For instance, it can display the text of a status message in a different language.

Accept-Language: LANGUAGE

Example

To set the preferred response language to Spanish, add this header:

Accept-Language: es

cURL Example

To apply the language in a cURL request, add the following header:

-H "Accept-Language: es"

Available Languages

The following list contains all the currently available languages. Note that setting a language header does not guarantee a translated response, as not all texts are translated. If no language is set or a translation is unavailable, the default response will be in English.

Code Language
en English
de German
fr French
es Spanish
ru Russian
it Italian
el Greek
pl Polish
pt Portuguese
lt Lithuanian
ko Korean
ja Japanese
zh Chinese
id Indonesian
tr Turkish
nl Dutch
ro Romanian
fi Finnish
cs Czech
hu Hungarian
ar Arabic
nb Norwegian Bokmål
sk Slovak
sl Slovenian
sv Swedish
lv Latvian
et Estonian
bg Bulgarian
uk Ukrainian
da Danish