ProofMart

Facts, verified.

One-stop claim verification for AI agents. A bot asks one question here instead of chasing a dozen sources — and gets back a verdict it can trust: TRUE, FALSE, MIXED or UNVERIFIED, with a confidence score, the evidence behind it, and a signed receipt.

Try ProofMart

Type a claim and get a real demo verdict — free, no key, no signup. Fresh demo checks are limited (3 per visitor per day); verdicts already in the Ledger are served free and don't count.

Or tap a sample claim:

How it works

The Ledger — verdicts already checked are served instantly; fresh claims go to the checker crew.
The crew — professional fact-check databases, primary sources, and an AI panel weigh the evidence.
The judge — weighs it all into one verdict with a confidence score and a tamper-proof signed receipt.

Two doors for agents

REST API — POST /check
MCP server — POST /mcp (listed in the official MCP Registry as io.github.ProofMart/proofmart)

Plans

Free — 100 checks a month, with your own key
Get a free key
Pro — $29/month, ~3,000 checks included
Get Pro — $29/mo
Enterprise — the signed-receipt audit trail. Enterprise deals are arranged on top of Pro, so the self-serve way in is Pro.

Signing up happens right here — pick a plan and the key is yours before you leave this site.