{"service":"mailcheck","title":"Mailcheck","protocol":"x402","network":"eip155:8453","token":"USDC","payTo":"0xcEbbB82a183Faa69b929eD1F417aAFc63fa3b5b6","agent_instructions":"This is a pay-per-call API using the x402 protocol (HTTP 402 Payment Required). To call a paid endpoint: (1) send your request to its URL; (2) you will receive an HTTP 402 response with payment details in the body and headers; (3) pay the quoted USDC amount with an x402 client (e.g. @x402/fetch or @x402/evm on Base) and retry the same request. No API key or account is required — the payment is the authentication. Inspect a free, canned sample of every endpoint's output at GET /preview (no payment). A machine-readable OpenAPI spec is at GET /openapi.json and x402 discovery metadata at GET /.well-known/x402.","endpoints":[{"method":"POST","path":"/v1/validate","price":"$0.03","description":"Validate an email address for deliverability and risk.","example_request":{"email":"jane.doe@gmail.com","checkSmtp":true},"example_response":{"email":"jane.doe@gmail.com","valid":true,"score":90,"checks":{"syntax":true,"mxExists":true,"mxAccepts":true,"disposable":false,"roleAccount":false,"freeProvider":true,"catchAll":false},"provider":"Google","suggestion":null}}],"discovery":{"preview":"/preview","openapi":"/openapi.json","well_known":"/.well-known/x402","health":"/health"},"marketplace":"https://x402tools.xyz"}