This is the package with the smart contract code that powers Arbitrum Nitro. It includes the rollup and fraud proof smart contracts, as well as interfaces for interacting with precompiles.
For more information see https://developer.arbitrum.io/intro
For the deployed addresses of these contracts for Arbitrum chains see https://developer.arbitrum.io/useful-addresses
For the token bridge contracts see https://github.com/OffchainLabs/token-bridge-contracts
Compile these contracts locally by running
git clone https://github.com/offchainlabs/nitro-contracts
cd nitro-contracts
yarn install
yarn build