This repository is a proof-of-concept for EIP-7702.
Live demo: https://7702-greeter.vercel.app/
- Burner wallet: stored in the browser's local storage
- Implementation contract: a simple greeter contract, edited to support EIP-7702 EOA smart accounts
- Activation: signs the authorization message to use the implementation contract's code and makes an initial greeting update
- Revokation: signs an authorization message with the zero address to revoke the delegation
- Updating your greeting: gaslessley update the greeting to a new value of your choosing
- Sponsored transactions: all transactions are sponsored (by the sequencer on Odyssey, by a faucet mechanism locally)
- A look under the hood: you can see the associated code and storage slot changes!
- A batcher contract that allows you to batch multiple transactions together from your 7702-enabled EOA smart account
- Using some example contracts (Faucet, BuyableToken, FreeToken) to demonstrate the flexibility of EIP-7702
- Drop multiple assets and then Move them to another burner in a single transaction!
- Using new burner wallets in indexedDB (to avoid delegate conflicts with the existing burner wallet)
- Still on Odyssey so sponsored by the sequencer!
- The Ithaca examples are great, but with all the delegation and authorization in the smart contract as well as the EIP-7702 spec and Viem implementation, it was a little hard to understand what was happening in each step. This much dumber example hopefully demonstrates the bare bones of EIP-7702.
- This is currently burner wallets only, as JSON-RPC accounts are not currently supported by Viem.
- Your smart contrat will need a fallback function or your EOA will no longer be able to receive ETH! (But you can still call a regular sendTransaction with value)
- Transactions from the local anvil node's inbuilt accounts didn't work as expected (instead using ephemeral faucet-funded accounts in local development to mimic the sequencer sponsor)
- In moving to Odyssey, it was slightly tricky to get sponsored transactions to work, as the sponsored transactions seemed to fail silently (i.e. if the Greeting signature was invalid), which was made more difficult as...
- If the initial transaction to initiate the delegation includes contract calls, those won't currently show up on the Odyssey block explorer (which is a reminder that various tooling in the ecosystem will need to be updated to support this new pattern)
- This functionality breaks some assumptions:
- EOAs can now run code
- Certain smart contracts can have a signing key
- You can no longer revoke ownership of all smart account
- Storage is forever! (i.e. if you revoke the delegation, the storage is still there)
- Which means you need to be careful with "upgrading" the smart contract code!
- Interacting with multiple EOA smart accounts in one transaction (e.g. to withdraw from all your EOAs at once!)
- EIP-7702
- Viem EIP-7702
- EXP-0001: Account Delegation with EIP-7702
- ORC-0001: Sequencer-sponsored Transactions
Many thanks to Viem and Ithaca for the supporting tooling and documentation!
Before you begin, you need to install the following tools:
- Node (>= v18.18)
- Yarn (v1 or v2+)
- Git
Install dependencies:
yarn install
To run on the Odyssey Testnet, using the predeployed contract:
yarn start
Running locally:
Create an .env file in /packages/nextjs:
NEXT_PUBLIC_ENVIRONMENT=localhost
Run a local anvil node:
yarn chain
Deploy the contract:
yarn deploy
Start the Next.js app:
yarn start
Batcher deployed at: 0x5e7F2C68cF06F9d5070F7ebb045E9bF1b7E84674 Faucet deployed at: 0x1a8DB8Cac4fe7aEbB745921096EF0b822E8135a2 FreeToken deployed at: 0xB0FD1eA6545D3F8f80d96e028b7a703331f0F768 BuyableToken deployed at: 0x7966030da476C2607DeFf7971f82623FDAd1fA41
forge verify-contract
--rpc-url https://odyssey.ithaca.xyz
--verifier blockscout
--verifier-url 'https://odyssey-explorer.ithaca.xyz/api/'
--compiler-version v0.8.28
0x7966030da476C2607DeFf7971f82623FDAd1fA41
contracts/BuyableToken.sol:BuyableToken