sponsored-cctp-extension-contracts

Smart contract for CctpExtensionV2 -- enables sponsored cross-chain USDC transfers via CCTP using batch EIP-3009 receiveWithAuthorization with nonce-bound deposit parameters.

Solidity Version

This repo uses Solidity 0.8.28. This is a standalone contract repo that defines its own minimal interfaces for external dependencies (TokenMessengerV2, EIP-3009 token), so it is not constrained by the 0.7.6 pragma in the upstream evm-cctp-contracts source.

Prerequisites

• Foundry
• Node.js (v18+)
• Yarn

Setup

# Clone with submodules
git clone --recurse-submodules <repo-url>

# Install Solidity linter
yarn install

# Build
make build

# Run tests
make test

# Run linter
yarn run lint

Before pushing

make build    # compile
make test     # all tests pass
yarn lint     # no lint errors

Project Structure

src/                          # Solidity source contracts
  CctpExtensionV2.sol         # Main contract
  interfaces/                 # Contract interfaces
test/                         # Test files and mocks
script/                       # Deployment scripts
docs/                         # Design docs (to be added)