Defacta

Large language models produce fluent text that is sometimes confidently wrong. Defacta checks AI-generated content against credible sources, filters out hallucinations, and flags bias, manipulation, and deception - and returns a structured JSON verdict you can act on. Call it from a REST API, wire it into agents over MCP, or check content in place with the browser extension.

Start verifying in 5 minutes · See the integrations

What you get#

Catch hallucinations#

Identify claims in AI output that credible sources do not support - before you ship the answer or act on it.

Verify facts against real evidence#

Each claim is checked against credible sources, so you gate on evidence instead of model confidence.

Flag manipulation#

Surface bias, manipulation, and deception patterns in the text, not just factual errors.

Get structured output#

Results come back as JSON you can parse, store, and branch on - no scraping free text.

Three ways to use it#

• REST API - call it from any backend or pipeline.
• MCP integration - give agents the ability to fact-check their own output before acting.
• Browser extension - verify content inline, right where you read it.

Ready to try it? Run your first verification.