A claim is a single verifiable statement extracted from your content. For example, "The Earth is 4.5 billion years old" is one claim. A paragraph might contain 3-5 claims. The API automatically extracts and counts individual claims.

Yes. The Playground lets you test the API without creating an account. For programmatic access, create a free account to get your API key — no credit card required.

You'll receive a 429 response with a Retry-After header. Upgrade to a higher plan for increased limits.

An MCP server is coming soon and will be published to the Anthropic Connector Directory and as an open-source package. In the meantime, the REST API works with any agent framework.

The Factive app is our demonstration site — a fact-checking app that shows fact-checking working in a live environment. The API gives developers and AI agents programmatic access to the same fact-checking pipeline. Same engine, different interfaces.