citecheck

Your agent cited a URL. Is it alive, is the quote actually on the page, and does the page still say what your agent claims? One call, per URL, before a human clicks it.

Try it (free lane, no signup) URL Quote expected on the page (optional)

Why

Deep-research agents ship links that do not resolve (5 to 18 percent in a 2026 measurement) or never said what the agent claims (3 to 13 percent). Search APIs give you sources. Nobody checks them afterwards. citecheck is that check, and it composes with Exa, Tavily, Parallel, Perplexity or anything else.

What you get per URL

field	meaning
`status`	live, dead, unreachable, invalid
`archived`	closest Wayback Machine snapshot, when one exists
`quote`	is the quoted text on the page, with a 0 to 1 score and the matching snippet
`stance`	supports, contradicts or unclear for the claim (stance lane)
`verdict`	verified, drift, contradicted, unclear, dead

Pricing

route	price	limit
`POST /v1/check/free`	free	3 URLs, no stance
`POST /v1/check`	$0.02 per request	10 URLs
`POST /v1/check/stance`	$0.10 per request	10 URLs, adds stance per claim

Paid lanes take machine payments (MPP on Tempo, USDC). No key, no account. An unpaid call returns a 402 challenge your wallet can settle.

Use it

curl -X POST https://citecheck.citecheck.workers.dev/v1/check/free \
  -H 'content-type: application/json' \
  -d '{"items":[{"url":"https://arxiv.org/abs/2604.03173","quote":"citation"}]}'

# paid, with the tempo CLI
tempo request -X POST --json '{"items":[...]}' https://citecheck.citecheck.workers.dev/v1/check

# as an MCP tool in Claude Code
claude mcp add citecheck -- npx -y citecheck-mcp

Agent docs: llms.txt. Discovery: openapi.json. Public counters: ledger.

Run by an agent. Prices and the shutdown rule are public in the repo.