{"uid":"cap_y5kwFDaSrVsMU4fGzKKIi","slug":"molcloud-crypto-signature-verifier-2e0a0abf","name":"MolCloud Crypto Signature Verifier","description":"41 pay-per-request AI, search, headless browser, crypto alpha & memory APIs for autonomous agents settling in USDC on Base via x402 v2.","url":"https://api.molcloud.net/api/crypto/verify-signature?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"message":{"type":"string","description":"Original signed plaintext message"},"signature":{"type":"string","description":"Hex signature string (0x...)"},"expectedSigner":{"type":"string","description":"Expected EVM wallet address (0x...)"}}},"responseSchema":{"type":"json","example":{"data":{"valid":true},"status":"success","endpoint":"/api/crypto/verify-signature"}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.003","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.003/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.003","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.003","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm__QBwSgmFOhs5FFCef6vOP","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.003","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Verifies that an EVM wallet signature matches an expected signer address for a given plaintext message","exampleAgentPrompt":"Can you verify whether this hex signature '0xabc123...' was actually produced by the wallet address '0xdef456...' for the message 'Login to MyApp at 1234567890'?","exampleUseCases":[{"title":"Wallet-based login authentication","prompt":"I need to verify that user wallet 0xA1b2C3... actually signed the login challenge message 'Authenticate to DashboardApp: nonce=99271' — the signature they provided is 0x4f8a2b... Can you confirm if it's valid?"},{"title":"DAO proposal signature check","prompt":"Before counting this governance vote, can you check whether the signature 0xdeadbeef... really came from wallet 0x1234abcd... for the message 'Vote YES on Proposal #42'?"},{"title":"Agentic task authorization verification","prompt":"My agent received a signed instruction saying 'Transfer 500 USDC to vault' with signature 0xfeed9876... — verify that the expected owner wallet 0xOwner123... actually signed that message before I proceed."}],"resultDescription":"Returns a JSON object with a 'valid' boolean indicating whether the provided hex signature was created by the expected EVM wallet address for the given plaintext message, along with a status string and the endpoint path.","failureModes":["Invalid or malformed hex signature string causes verification failure","Expected signer address is not a valid EVM address format (missing 0x prefix or wrong length)","Message mismatch — signature valid but for a different message content","Missing required fields (message, signature, or expectedSigner) returns an error","Network or gateway error results in a non-200 response","Payment failure via x402 protocol prevents the request from being processed"],"whenToPreferThis":"Use this endpoint when you need a quick, pay-per-request cryptographic signature verification for EVM-compatible wallets without running your own on-chain or local verification infrastructure. Ideal for AI agents that need to authenticate users or instructions via wallet signatures as part of autonomous workflows, especially when settling micropayments in USDC via x402. Prefer this over rolling your own ethers.js/web3 verification when you need a hosted, stateless API call.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-17T12:40:56.135Z","isFirstParty":false,"canonicalSlug":"molcloud-crypto-signature-verifier-2e0a0abf"}