Tools
Polygraph, where you work.
In your browser, in your AI assistant, or in your own code. One account, one set of credits: reading is free, and only a check spends.
MCP · Model Context Protocol
Ask your assistant to check it.
What your assistant can do
Search fact checks
Find published Polygraph claims and professional fact checks on a topic, filtered by verdict or source.
Read a post or a claim
Get a post’s full check, or one claim’s verdict, confidence, findings and sources.
Check a new post
Quote the price, then run the check. Only a read + check connection can do this, and it spends your credits.
Keep track of your account
List your recent checks and see your credit balance.
| Tool | What it does | Needs |
|---|---|---|
search_fact_checks | full-text search over published Polygraph claims and the professional fact-check index; filter by verdict and source. | Read |
get_post | one post's full Polygraph result by content id: status per stage, every claim with verdict, findings and sources, the Polygraph score. | Read |
get_claim | one claim by numeric id or published slug: verdict, confidence, findings, sources, history, where it was said. | Read |
get_check | one published post check by slug: the post, its verdict counts and every published claim on it. | Read |
quote | what checking a post would cost in credits, and the account's balance — nothing is charged. | Read + check |
check | fact-check one post — SPENDS the account's credits (quote first); returns the content id to read with get_post. | Read + check · spends |
get_balance | the account's credit balance. | Read |
list_my_checks | the account's recent checks, newest first, with claim counts per verdict and run status. | Read |
Connect it
Sign in once from the assistant and it gets its own key, named for it, with the scope you choose and an optional monthly credit cap. Cap or revoke it any time on your keys page.
https://polygraphs.xyz/mcp- 1Open Settings → Connectors → Add custom connector.
- 2Name it Polygraph and paste https://polygraphs.xyz/mcp, then click Connect.
- 3Sign in to Polygraph, choose Read or Read + check and an optional monthly credit cap, and approve. A key named “Claude (MCP)” appears on your keys page.
- 1Add the server, then run /mcp, pick polygraph and choose Authenticate.
- 2Or skip the sign-in and pass a key as a header.
claude mcp add --transport http polygraph https://polygraphs.xyz/mcpclaude mcp add --transport http polygraph https://polygraphs.xyz/mcp \
--header "Authorization: Bearer $POLYGRAPH_KEY"- 1Open Settings → Apps & Connectors → Advanced and turn on Developer mode.
- 2Create a connector with the URL https://polygraphs.xyz/mcp and Authentication set to OAuth.
- 3Sign in to Polygraph and approve when ChatGPT sends you there.
Custom connectors depend on your ChatGPT plan.
- 1Point it at https://polygraphs.xyz/mcp (Streamable HTTP). A client that supports MCP authorization signs you in by itself.
- 2A client that doesn’t: send a key from your keys page as Authorization: Bearer pg_….
No account? Read-only MCP
A second MCP server serves published fact checks with no sign-in at all. It can search and read, never check or spend.
https://polygraphs.xyz/api/mcp| Tool | What it does | Needs |
|---|---|---|
search_fact_checks | full-text search over published Polygraph claims and the professional fact-check index; filter by verdict and source. | Nothing |
get_claim | one published claim by slug: verdict, confidence, summary, rated sources, carrying posts, history, plus schema.org ClaimReview. | Nothing |
get_check | one published post check by slug: the post, its verdict counts and every published claim on it. | Nothing |