{"uid":"cap_jdp0eGSXPCQR586ID4GBl","slug":"eip-3009-x402-offline-signing-verification-receipt-audit-toolkit-ca72ef04","name":"EIP-3009 / x402 Offline Signing, Verification & Receipt Audit Toolkit","description":"EIP-3009 / x402 Offline Signing, Verification & Receipt Audit Toolkit (Python, no dependencies). Pure-Python (standard library only) toolkit for the EVM x402 'exact' flow: sign an EIP-3009 T First approved purchase: 0.01 USDC total where maker terms permit; later 0.25 USDC plus tax. Stored ZIP download; commercial use, no redistribution. Verified by Speedbot for this version. Generate a private checkout_key and request_id; email and delivery consent required.","url":"https://speedbot.dev/api/products/product_c5e2808a79b5445192e26822cdbcbce3/versions/version_59eee7f20d594b27b209b1f432db4784/buy?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"email":{"type":"string","pattern":"^[^\\s@]+@[^\\s@]+\\.[^\\s@]+$","description":"Your receipt/recovery email; required when paying, never copied to the facilitator."},"request_id":{"type":"string","maxLength":100,"minLength":16,"description":"Generate a unique purchase identifier and retain on every retry."},"checkout_key":{"type":"string","pattern":"^[a-fA-F0-9]{64}$","writeOnly":true,"description":"Generate 32 private random bytes as 64 hex characters. Required when paying. Retain on every retry."},"digital_delivery_consent":{"type":"boolean","const":true,"description":"Required for a purchase: request immediate digital delivery and acknowledge the applicable withdrawal consequence."}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.25","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":"$0.25/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.25","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.25","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_n0asWlLF5nW0TVuQjVvuc","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.25","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Purchase and download a pure-Python (no-dependency) toolkit for signing, verifying, and auditing EIP-3009 transfers in the EVM x402 payment flow","exampleAgentPrompt":"Buy me the EIP-3009 / x402 offline signing toolkit from Speedbot — I need to sign and verify EVM USDC payment authorizations in pure Python with no dependencies. My email is dev@example.com, I consent to digital delivery, and I'll generate my own checkout_key and request_id.","exampleUseCases":[{"title":"Agent self-pays for signing toolkit","prompt":"Purchase the Speedbot EIP-3009 offline signing toolkit for me — I'm building an autonomous payment agent that needs pure-Python USDC authorization signing with no pip installs. Use my email agent-ops@mycompany.com, I consent to immediate digital delivery, and generate a checkout_key and request_id for the transaction."},{"title":"Developer auditing x402 payment receipts","prompt":"I need to audit EIP-3009 transfer authorizations from our x402 payment flow without pulling in any external Python libraries. Can you buy the Speedbot offline signing and receipt audit toolkit for me? My email is alice@startup.io and I agree to digital delivery."},{"title":"Offline signing for air-gapped EVM wallet","prompt":"Get me the Speedbot pure-Python EIP-3009 toolkit — I want to sign EVM USDC transfers offline on an air-gapped machine running only the Python standard library. My receipt email is security@wallet.dev and I consent to digital delivery."}],"resultDescription":"A ZIP file download containing a pure-Python (standard library only) toolkit implementing EIP-3009 TransferWithAuthorization signing, verification, and receipt auditing for the EVM x402 exact payment flow, delivered digitally upon successful USDC payment.","failureModes":["Missing or invalid email format returns validation error","checkout_key not provided as 64 hex characters causes rejection","request_id shorter than 16 characters is rejected","digital_delivery_consent not set to true blocks purchase","Payment authorization failure if USDC balance insufficient","Retry with same request_id required if network interruption occurs during payment"],"whenToPreferThis":"Choose this endpoint when you need a dependency-free, pure Python Standard Library implementation of EIP-3009 offline signing and x402 payment flow verification — especially in environments where pip installs are restricted, air-gapped setups are required, or you want auditable USDC transfer authorization without third-party library risk.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-11-03T06:32:41.268Z","isFirstParty":false,"canonicalSlug":"eip-3009-x402-offline-signing-verification-receipt-audit-toolkit-ca72ef04"}