{"uid":"cap_zPE5tLOuKYI9qUgxvajTL","slug":"signalharness-eoa-signature-verifier-51d2aac8","name":"SignalHarness EOA Signature Verifier","description":"Explore 330 pay-per-call x402 API services and 27 agent-native digital products, with Base USDC pricing, secure Polar checkout, and free discovery.","url":"https://signalharness.ai/api/agent/services/eoa_signature_verify/invoke","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"eoa_signature_request":{"type":"string","maxLength":65536,"minLength":2}}},"responseSchema":{"type":"json","example":{"replay":false,"result":{"warnings":["Verification proves key control for the supplied message only, not identity or authorization."],"service_id":"eoa_signature_verify","evidence_scope":"caller_supplied_data","eoa_signature_verification":"{\"address\":\"0x0000000000000000000000000000000000000001\",\"encoding\":\"utf8\",\"valid\":false}"},"status":"succeeded","receipt":{"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","usage":[],"status":"succeeded","network":"eip155:8453","artifacts":[],"endedAtMs":0,"latencyMs":0,"paymentId":"example-payment","receiptId":"example-receipt","requestId":"example-request","serviceId":"eoa_signature_verify","executionId":"example-execution","startedAtMs":0,"amountAtomic":"10000","resultSha256":"5fb43bede3ca02db81d5e0fc5a48a9e770301df3402aca41ef7f62d1e73cf6c8","serviceVersion":"1.0.0","settlementReference":"0x0000000000000000000000000000000000000000000000000000000000000000"},"artifacts":[],"requestId":"example-request","executionId":"example-execution"}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.01","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":"$0.01/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_97PwaxCeKAJUgwYaLcivt","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.01","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Verifies an Ethereum EOA (Externally Owned Account) cryptographic signature against caller-supplied data and returns the verification result with warnings and evidence scope.","exampleAgentPrompt":"Can you verify this Ethereum EOA signature for me? Here's the signature request payload — I need to know if it's valid, who signed it, and whether it's a replay.","exampleUseCases":[{"title":"Wallet ownership proof for login","prompt":"A user just submitted an Ethereum wallet signature to log into my app — can you verify this EOA signature to confirm they actually own that wallet address before I grant them access?"},{"title":"Replay attack detection for signed transaction","prompt":"I received this signed message from an Ethereum address and I need to check if it's valid and whether it's a replay attack — here's the signature payload."},{"title":"Smart contract interaction authorization","prompt":"Before processing this user's request, verify this EOA signature they provided to authorize the action — I need to know if it checks out and if there are any warnings about it."}],"resultDescription":"Returns a JSON object containing: a boolean 'replay' flag indicating whether the signature appears to be a replay, an 'eoa_signature_verification' result string with the verification outcome, a list of 'warnings', an 'evidence_scope' string (e.g. 'caller_supplied_data'), a status field ('succeeded'), and a full receipt with payment metadata including network, asset, payment ID, request ID, execution ID, timestamps, and a SHA-256 hash of the result.","failureModes":["Malformed or truncated signature string returns validation error","Signature string exceeds 65536 character limit","Replay attack detected and flagged in warnings","Invalid Ethereum address format in payload","Signature does not match the claimed signer","Network or service unavailability returns non-200 status","Payment failure via x402 protocol blocks execution"],"whenToPreferThis":"Use this endpoint when you need a pay-per-call, agent-native EOA signature verification service that integrates with the x402 micropayment protocol on Base (EIP-155:8453). Ideal for AI agents operating autonomously in Web3 contexts where per-call billing via USDC is preferred over subscription APIs, and where replay detection and evidence scoping are needed alongside basic signature validation.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-16T00:52:54.273Z","isFirstParty":false}