AttestPage recipes

Last updated: 2026-10-10

Short, runnable recipes for calling AttestPage from an agent. In each one, the agent checks a source before it cites it. Copy one, run it, then change the tools to fit your agent.

Recipe	Runnable file	Framework	Language	How it calls AttestPage	Pays with x402
langchain.md	langchain.mjs	LangChain (`create_agent`, `createAgent`)	Python and JavaScript	Python: a small client using only the standard library. JavaScript: the client from the OpenAI Agents SDK recipe	Python: no, free trial, then returns the price. JavaScript: yes, when a key is set
openai-agents-sdk.md	openai-agents-sdk.mjs	OpenAI Agents SDK	JavaScript	A small client over `fetch`	Yes, with `@x402/fetch` when a key is set
claude-agent-sdk.md	claude-agent-sdk.mjs	Claude Agent SDK	JavaScript	The `quoteproof-mcp` MCP server (stdio)	Yes, when `QUOTEPROOF_X402_KEY` is set
fetch-x402.md	fetch-x402.mjs	None	JavaScript	Plain `fetch`, one x402 payment step by step	Yes

Run a recipe

Each page shows its code in full, with what to install and the command that runs it. The LangChain (JavaScript) and OpenAI Agents SDK recipes share one client, [attestpage.mjs](/docs/examples/attestpage.mjs), shown on the OpenAI Agents SDK page.

Plain fetch with x402 always pays, so it needs ATTESTPAGE_X402_KEY, the key of a wallet made only for testing.
OpenAI Agents SDK runs on the free trial with no wallet key; it needs OPENAI_API_KEY for the model.
LangChain (JavaScript) and Claude Agent SDK run on the free trial with no wallet key; they need ANTHROPIC_API_KEY for the model.

Service address

https://vehcdj664efetfrsolne5umanq.srv.us

Every recipe uses this address by default. To call another address, set ATTESTPAGE_URL (the MCP server reads QUOTEPROOF_URL).

Routes and prices

Prices are per call in USDC. The full list is at [/pricing.json](https://vehcdj664efetfrsolne5umanq.srv.us/pricing.json) and in the OpenAPI document.

Route	What it answers	Price
`POST /v1/verify/quote`	Is this quote on the page at this URL: `exact`, `fuzzy` or `none`, with offsets and page hashes	US$0.01
`POST /v1/verify/citations`	The same for up to 10 quote and URL pairs	US$0.10 per batch
`POST /v1/verify/quotes`	The same for up to 20 quotes on one page, fetched once	US$0.08 per batch
`POST /v1/verify/document`	Every quote with its link in a finished document, checked on the live page	US$0.10 per part of up to 10 pairs
`POST /v1/verify/document/preview`	The pairs a document check would make, and its price	free
`POST /v1/fetch`	A page as clean text, with a verdict on what came back (`real`, `bot_wall`, `js_shell`, `paywall`, `http_error` and others)	US$0.002
`POST /v1/check/links`	Status, redirects, final URL and verdict for up to 10 URLs	US$0.005 per batch
`POST /v1/check/packages`	Whether up to 10 npm, PyPI or crates.io names exist, with latest version	US$0.005 per batch
`POST /v1/attest`	A signed, timestamped receipt over a SHA-256 you send	US$0.002
`POST /v1/receipt/verify`	Checks a receipt's signature against the published keys	free

Every answer from a paid route carries a receipt: an Ed25519-signed JWS of what the fetcher saw and when. A receipt records what was on the page at that time, not whether a statement on it is correct.

How a call is paid

Free trial. Send the header Quoteproof-Trial: 1 and a paid route answers without payment, a few calls a day, with at most 3 URLs or pairs per batch. Once the day's trial calls are used, a trial request gets 429 trial_exhausted and is not charged. See Limits.
402 Payment Required. A valid request gets 402 when it has no trial header or is a trial batch over 3 items. The offer is in the PAYMENT-REQUIRED header: base64 JSON with the amount (USDC, 6 decimals), network and pay-to address.
x402. Sign the offer and send the same request again with the PAYMENT-SIGNATURE header. Payment settles only when the route answers with a status below 400; the answer then carries a PAYMENT-RESPONSE header.

Payments run on Base Sepolia (eip155:84532), a test network. Test USDC has no value. Use a wallet made only for testing, holding only test USDC.

A bad request gets 400 before any offer and is never charged. Error codes are listed at [/docs/errors](https://vehcdj664efetfrsolne5umanq.srv.us/docs/errors).

Try it without code

# Free: what a verify/quote answer looks like
curl -s https://vehcdj664efetfrsolne5umanq.srv.us/v1/sample/quote

# The 402 offer for verify/quote, decoded
curl -s -o /dev/null -D - -X POST https://vehcdj664efetfrsolne5umanq.srv.us/v1/verify/quote \
  -H 'content-type: application/json' -d '{}' \
  | grep -i '^payment-required:' | cut -d' ' -f2 | tr -d '\r' | base64 -d