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Account Abstraction Architecture

This page illustrates the transaction flow for SBC's Account Abstraction implementation, covering both ERC-4337 for gasless transactions and EIP-7702 for atomic multi-step operations.

ERC-4337 Transaction Flow

The following diagram illustrates how SBC's Account Abstraction implementation works using ERC-4337:

ERC-4337 transaction flow: the user submits a UserOperation to the SBC Bundler, which bundles it to the EntryPoint contract. The EntryPoint validates against the smart contract wallet, draws gas from the SBC Paymaster, and executes the call on the target contract. ERC-4337 transaction flow: the user submits a UserOperation to the SBC Bundler, which bundles it to the EntryPoint contract. The EntryPoint validates against the smart contract wallet, draws gas from the SBC Paymaster, and executes the call on the target contract.

Flow Explanation

  1. User Submission: The user creates and signs a UserOperation, which is like a transaction but with more flexibility.

  2. Bundler Processing: SBC's bundler service:

    • Validates the UserOperation
    • Bundles it with other operations for efficiency
    • Submits the bundle to the EntryPoint contract

  3. Wallet Validation: The EntryPoint contract validates:

    • The wallet's signature
    • The operation's validity
    • Required permissions

  4. Gas Handling: Instead of users paying gas:

    • The EntryPoint coordinates with the SBC Paymaster
    • SBC covers the gas, from the Paymaster's own deposit in that network's EntryPoint contract
    • Users hold no gas token and spend none of their own balance on gas

  5. Payment Authorization: The Paymaster:

    • Checks the operation against SBC's sponsorship rules
    • Signs the UserOperation to authorize sponsorship
    • Manages the deposit that funds it

  6. Execution: Finally:

    • The EntryPoint executes the validated operation
    • The target contract receives the call
    • The transaction is completed without user gas fees

EIP-7702 Transaction Flow (Upcoming)

EIP-7702 is a new proposal that enables EOAs (regular wallets) to temporarily execute smart contract code during a transaction without permanently converting to a smart account. The key aspects include:

  1. Temporary Smart Contract Execution: EOAs can specify a contract_code field in their transaction that will be executed only during that specific transaction.

  2. No Permanent Changes: Unlike other approaches, the smart contract code is automatically removed after the transaction completes, keeping the EOA's original properties.

  3. Direct Integration: No need for additional contracts or infrastructure - the EOA directly executes the smart contract code, making it simpler and more secure than alternatives like EIP-3074.

  4. ERC-4337 Compatible: The approach aligns with the broader account abstraction roadmap and works seamlessly with existing ERC-4337 infrastructure.

Integration with SBC AppKit

SBC's AppKit abstracts much of this complexity, providing developers with a simple API to interact with both ERC-4337 and EIP-7702 transaction flows. By using the AppKit, developers can:

  • Send gasless UserOperations without managing bundler or paymaster interactions directly.
  • Prepare for atomic transaction bundles with EIP-7702 support once fully integrated.

Next Steps