How to use AttestPage tools from an MCP client, step by step with curl

Q: How much does a tool call cost?

It costs the price of its route, from US$0.002 for attestpage_attest to US$0.10 for attestpage_verify_citations. The table above lists every tool.

Last updated: 2026-10-13

To give an MCP client the AttestPage tools, add the remote endpoint https://vehcdj664efetfrsolne5umanq.srv.us/mcp. Each tool runs one paid route, from US$0.002 to US$0.10 per call, and the client pays per call in USDC with x402. Nothing is installed.

This guide lists the tools, calls one with curl, reads the 402 offer and shows where the payment goes. For the full reference, see MCP server.

What the endpoint does

Speaks streamable HTTP. Each POST to /mcp carries one JSON-RPC message and gets one JSON answer. There are no sessions and no event stream, so GET returns 405.
Gives one tool per route. A tool call runs the matching route on this server, so prices, limits and refunds are the same as calling the route directly.
Needs no account. There is no key or sign-up. The caller pays with an x402 payment in the call.

Price

Each tool costs what its route costs, paid in USDC with x402 v2 on Base mainnet (real USDC). A call that fails validation is never charged. All prices: pricing.json.

Tool	Does	Price per call
`attestpage_verify_quote`	Checks a quote against a web page	US$0.01
`attestpage_verify_quotes`	Checks up to 20 quotes on one page	US$0.02
`attestpage_verify_citations`	Checks up to 10 quote and URL pairs	US$0.10
`attestpage_verify_document`	Checks the quotes and links in a document, 10 pairs per part	US$0.10
`attestpage_fetch`	Reads a page as clean text with a signed verdict	US$0.002
`attestpage_recheck`	Compares a page with an earlier receipt	US$0.003
`attestpage_check_links`	Checks up to 10 links	US$0.005
`attestpage_check_packages`	Checks up to 10 package names on npm, PyPI or crates.io	US$0.005
`attestpage_attest`	Signs a timestamped receipt over a SHA-256 hash	US$0.002

Two tools are free: attestpage_verify_receipt checks a receipt, and attestpage_preview_document previews a document check.

1. Add the endpoint to your client

{
  "mcpServers": {
    "attestpage": { "type": "http", "url": "https://vehcdj664efetfrsolne5umanq.srv.us/mcp" }
  }
}

To pay from your own wallet key within limits you set, run the local server instead: MCP server.

2. List the tools

curl -s -X POST https://vehcdj664efetfrsolne5umanq.srv.us/mcp -H 'content-type: application/json' \
  -d '{ "jsonrpc": "2.0", "id": 1, "method": "tools/list" }' | jq -r '.result.tools[].name'

Each tool has an inputSchema for its arguments and an outputSchema for its result. The arguments are the body of the route, so the other guides apply: for example How to check links before citing them for attestpage_check_links.

3. Read the 402 offer

Call a tool with _meta["attestpage/trial"] set to false. That asks for the payment offer, and nothing is charged:

curl -s -X POST https://vehcdj664efetfrsolne5umanq.srv.us/mcp -H 'content-type: application/json' -d @- <<'EOF' \
  | jq '.result.structuredContent.accepts[0] | {scheme, network, amount}'
{ "jsonrpc": "2.0", "id": 2, "method": "tools/call",
  "params": { "name": "attestpage_fetch",
    "arguments": { "urls": ["https://www.iana.org/help/example-domains"] },
    "_meta": { "attestpage/trial": false } } }
EOF

The result has isError: true and the x402 payment requirements in structuredContent. amount is in USDC base units (6 decimals), so 2000 is US$0.002, the price of attestpage_fetch.

4. Pay and call again

Sign one of accepts with your wallet and put the payload in _meta["x402/payment"] of the same call. An x402 MCP client such as @x402/mcp does this for you. The answer is then the route's JSON in structuredContent, and _meta["x402/payment-response"] holds the settlement. Payment settles only when the route answers successfully.

Where the free trial is on, a call without a payment of up to 3 items uses the trial first. The cap applies to verify_citations, verify_quotes, verify_document (per pair), check_links and fetch (per URL), and a call above it gets the offer at once. check_packages has no cap: a call of up to 10 names runs as a trial.

5. Keep the receipt

Each paid result carries a signed receipt. Check it with the free tool attestpage_verify_receipt, or see How to check a signed receipt before you rely on it.

Questions

How much does a tool call cost?

It costs the price of its route, from US$0.002 for attestpage_attest to US$0.10 for attestpage_verify_citations. The table above lists every tool.

Do I need an account or an API key?

No. The caller pays each call with an x402 payment, and there is no sign-up.

Which MCP clients work?

Any client that can call a streamable HTTP endpoint with JSON-RPC. A client that signs x402 payments pays by itself; for other clients, use the local server in MCP server, which pays from your wallet key.

Is a call charged if it fails?

A call that fails validation is not charged. Every case is in Payments and Errors.