The Copyleaks API is a RESTful web service that uses HTTPS for secure communication. This guide provides a high-level overview of the core concepts you’ll need to understand to use the API effectively.

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Generating Your API Key

Your API Key is the first step to authenticating with the Copyleaks API. The authentication process involves exchanging this key for a temporary Access Token, which is then used to make API requests. For detailed instructions on how to generate your API key and authenticate, please see our complete Authentication Guide.

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Content Types

The Copyleaks API uses the JSON format for both requests and responses. You must send the Content-Type: application/json header in your requests. Our official SDKs handle this for you automatically.

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Submitting Content

Copyleaks can process content in several formats, depending on the endpoint you are using:
  • Raw Text: Submit plain text directly in the request body.
  • Base64 Encoded File: Submit a file by encoding its content into a Base64 string. The filename parameter, including the file extension, is used to determine the document type.
  • URL: Provide a public URL to a document, and Copyleaks will crawl and process its content.

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Request Size Limits

While there is no single global request size limit, specific endpoints have their own constraints. For text submissions, such as those to the AI Detector or Grammar Checker, there are character limits detailed on their respective pages. For file submissions, please refer to the Technical Specifications for detailed file size limits.

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Rate Limiting

The Copyleaks API enforces rate limits to ensure fair usage and stability. The default rate limit is 10 requests per second per account. However, specific endpoints may have different rate limits, which are detailed on their respective pages in the API reference. The API is set to handle up to 300 scans per minute (600 API calls). During high-traffic periods, we recommend building a simple queue on your side. This allows your system to send scan requests at a steady pace and ensures every scan is processed reliably. This capacity allows for processing over 1.2 million credits per day. If you send too many requests in a short period, you will receive a 429 Too Many Requests HTTP response. See Rate Limits for best practices on handling rate limit errors and Error Codes for complete error reference. If you require a higher rate limit, please contact our support team.

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Sandbox Mode

For development and testing, we provide a sandbox mode that allows you to make API calls without consuming credits or affecting your production data. To use it, include the "sandbox": true parameter in your request. The exact location of this parameter may vary by endpoint, so please refer to the specific endpoint documentation in the API Reference or our guides for implementation details. When in sandbox mode, the API will not perform a real scan, but will instead return mock data that simulates a real response. This allows you to test your integration and workflows without consuming credits.

Authentication

Learn how to exchange your API key for an access token to make API calls.

Rate Limits

Understand API rate limits and best practices for handling 429 errors.

Error Codes

Complete reference of API error codes and how to resolve them.