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.
WebMCP
Agents in your browser, too.
When an AI agent runs inside your browser, this site hands it Polygraph’s tools directly, through
navigator.modelContext. Nothing to install or configure — and browsers without WebMCP see nothing different.How it works
Every page offers search and reads
On any Polygraph page, an agent can search fact checks and read a claim or a check.
Check and claim pages add one more
On a check or a claim, the agent can read the page you are looking at, as structured data.
Signed in, it can check for you
Your browser adds quote, check, your checks and your balance. It uses your session — no key is ever put in the page.
You still confirm every check
A check asks you to confirm the price on the page first. An agent can never spend your credits on its own.
Example
// In a browser with WebMCP, an agent on this site sees Polygraph's tools.
// The site registers them; the agent calls them by name, for example:
search_fact_checks({ query: "school funding bill", verdict: "false" })The tools
| 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. | Every page |
get_claim | one published claim by slug: verdict, confidence, summary, rated sources, carrying posts, history, plus schema.org ClaimReview. | Every page |
get_check | one published post check by slug: the post, its verdict counts and every published claim on it. | Every page |
read_this_page | the published fact check or claim on the page the visitor is viewing. | Check and claim pages |
quote | what checking a post would cost in credits, and the account's balance — nothing is charged. | Signed in |
check | fact-check one post — SPENDS the account's credits (quote first); returns the content id to read with get_post. | Signed in · you confirm |
list_my_checks | the account's recent checks, newest first, with claim counts per verdict and run status. | Signed in |
get_balance | the account's credit balance. | Signed in |