Architecture

Resources

• Safe Modular Smart Account Architecture – Explained by Safe 2023-07-10
• Safe documentation > 🔰 Learn

Foundation

Singleton contract

• Contains the Safe business logic functions
• Functions modify the Safe proxy contract state data
• Not upgradeable (Immutable): Requires a new contract deployment for each version upgrade
  • Users can decide whether to upgrade through the Safe native app
• Deployed on each network where Safe is available

Proxy contract

• Forwards requests to the Singleton contract
• Contains the Safe state data, e.g., Owners, threshold, plugin addresses, and hook addresses
• Upgradeable (Mutable)

Safe SDK/API

• 3rd party apps can make requests to the Safe Singleton using the SDK/API.
• 3rd party apps act as wrappers to Safe accounts.
• E.g. Create new Safe accounts (Proxy instances), read and display Safe info

Factory contracts

• Used to deploy Singleton and Proxy contracts

Interfaces

Plugins/modules

• Apps that connect onchain contracts and web APIs
  • Connect to web APIs through oracle systems
• Sample use cases: Recovery mechanisms, session keys, and payment streaming
• Enabled through a Safe account approval
  • The transaction is implemented through the Singleton
  • The Singleton updates the proxy contract with the plugin address

Hooks/guards contract

• Smart contracts that verify and enforce onchain conditions before and after transactions occur
• Similar to event listeners

Function handlers/fallback handlers contract

• Default functions when a function is called within the Safe Proxy that does not exist
• Forwards the call to an external contract
• Usually these functions are nested within other contracts as an error handler

Signature verifiers

• Validates transactions for the Safe account
• Compatibility with externally owned accounts (EOAs) which have a private key to sign transactions, e.g. EIP-1271

ERC-4337

About

• Site: eips.ethereum.org/EIPS/eip-4337
• Creates a standard for smart accounts to customize verification
• Uses a new transaction object and separate mempool

Safe

• ERC-4337 integrations now supported in Safe{Core}’s Account Abstraction stack by Safe

Resources

• Safe wallet adds 'ERC-4337' to boost account abstraction features by The Block
• Ethereum’s ERC-4337 Standard: Explained by Ledger

Safe protocol

About

• Whitepaper: Safe{Core} Protocol
  
• FAQ: Safe{Core} Protocol FAQ
• Forum: Safe{Core} Protocol Whitepaper
• Github: Safe{Core} Protocol Specification

This is not financial, technical, or legal advice. Consult professionals and do your own research.