MetaMask Smart Accounts Kit

• What is a smart wallet?

  A smart wallet is a crypto wallet built with smart contracts on a blockchain. It doesn’t just hold assets. Smart wallets can follow programmable rules for how funds are spent, add security features like spending limits, or automate common tasks. With a smart wallet, everyday actions—like splitting payments or batching transactions—can be done at the wallet-level, not just by individual users.

• What is a smart contract?

  A smart contract is code stored on a blockchain that runs automatically when preset rules are met. Once deployed, it can move funds, manage wallets, run decentralized applications, or handle any logic you define—all without relying on a traditional server.

• What is account abstraction on Ethereum?

  Account abstraction lets developers define how accounts work on Ethereum, making smart contract wallets as flexible as regular accounts (EOAs). This means custom logic for signatures, gas payments (AKA network payments), and access control are possible, enabling new wallet features or user experiences.

• What is ERC-4337?

  ERC-4337 is an Ethereum standard making account abstraction practical without changing the core protocol. It lets users operate "smart accounts" with features like batch transactions, paymaster-sponsored gas, or social recovery, all managed by a smart contract wallet rather than a bare EOA.

• What is an account abstraction wallet?

  An account abstraction wallet (“AA wallet”) is a wallet powered by smart contracts that implements custom handling for transactions, access, and security. With tools like ERC-4337, these wallets can support batched actions, delegated spending, or even login with passkeys instead of seed phrases.

• What’s the difference between a smart wallet and a smart contract wallet?

  There’s no strict difference: “smart contract wallet” and “smart wallet” both refer to wallets managed by smart contracts (not by a simple private key). Their main draw is unlockable features—like account recovery, whitelists, or plug-in modules—even after launch.

• How does a smart contract wallet improve user experience?

  Smart contract wallets let you design programmable logic at the wallet level (e.g., multi-signature approvals, auto-payments, or usage controls). This means you can deploy upgradeable security, create custom payment flows, or automate recurring actions—all without relying on the end-user to sign every transaction.

• What’s a smart wallet in crypto?

  A smart wallet is a blockchain-based wallet managed (at least in part) by programmable code. This brings options like sending assets with no gas (sponsored by a paymaster), triggering multiple actions in one signature, or recovering ownership if a user loses access.

• What is an embedded wallet?

  An embedded wallet is a smart (or standard) wallet that’s built into an app or website. Users can interact with blockchain features—like payments or NFTs—without installing separate wallet software; the logic is integrated under the hood, simplifying onboarding.

• What is an AA wallet?

  An AA wallet (“account abstraction wallet”) is any wallet that takes advantage of Ethereum’s account abstraction features (like those in ERC-4337) to support custom signatures, alternate gas payment, and app-specific logic.

• What is an Ethereum smart contract wallet?

  It’s a wallet on Ethereum built as a smart contract, able to run code on-chain. This lets developers add new user flows, unique security setups, and novel account recovery options which aren’t available with basic Ethereum accounts.

Let’s talk about Standards

• Give me a TL;DR on 4337

  Account abstraction, specified by EIP-4337, is a mechanism that enables users to manage Smart Contract Accounts (SCAs) containing arbitrary verification logic. EIP-4337 enables SCAs to be used as primary accounts in place of traditional private key-based accounts, or externally owned accounts (EOAs).

  EIP-4337 introduces the following concepts:

  • User operation (UserOp) - A package of instructions signed by a user, specifying actions for the SCA to execute. UserOps are collected and submitted to the network by bundlers.

  • Bundler - A service that collects multiple UserOps, packages them into a single transaction, and submits them to the network, optimizing gas costs and transaction efficiency.

  • Entry point contract - A contract that validates and processes bundled UserOps, ensuring they adhere to the required rules and security checks.

  • Paymasters - Entities that handle the payment of gas fees on behalf of users, often integrated into SCAs to facilitate gas abstraction.

• How are Delegator Accounts connected or related to EIP-4337 Accounts?

  Delegator Accounts are EIP-4337 accounts, which use smart contracts to govern account logic and can use the 4337 EntryPoint contract to manage gas payment.

• How are Delegations connected to User Operations?

  Let’s explain this with an example.

  Bob (delegator) grants Alice a Delegation, (basically a permission) to transfer a NFT from Bob’s account to Carol’s account.

  For the action to occur, the delegation must have been signed by Bob.

  Alice redeems this delegation by sending a UserOp that executes the delegated action within the bounds of the caveats defined when the delegation was created.

  Since delegations can be offchain, they allow submitting fewer UserOps, saving gas, and reducing onboarding hurdles.

• How would Delegator Accounts fit in with EIP-7702?

  EIP-7702 adds a new transaction type that sets the code for an EOA. A delegator account can be the code that EOAs delegate their authority to, enabling all the powers of readable permissions, intents, and offchain permissions to be available to traditional EOA accounts.

• Give me a TL;DR of ERC-7710

  ERC-7710 is an ERC standard that defines the minimal interface necessary for Smart Contracts to delegate capabilities to other Smart Contracts, Smart Contract Accounts, or Externally Owned Accounts (EOAs). ERC-7710 resulted from the Delegation Framework.

  MetaMask Delegator Accounts implement ERC-7710 to allow redeeming its permissions in a way that can be compatible with other smart contract account implementations. By building this key interface as an open standard, we are inviting innovation in the category of more collaborative wallets, while ensuring ours is able to participate in this new open category.

• Give me a TL;DR of ERC-7715

  ERC-7715 is an ERC standard that seeks to unify the format in which permissions are requested and granted between Wallets and Dapps in order to execute transactions on the user’s behalf via “session keys” or “session accounts” (which can themselves be embedded smart contract accounts, like our Delegation Toolkit enables).

  Delegator Accounts are fully compatible with 7715 via 7710 Account Sessions.

• Is the Delegation Toolkit built to ERC-6900 or ERC-7579 specs?

  The Delegation Framework is an extensible permissions system that allows the sharing of authority in a flexible and attenuable way where delegations enable safe composition with other contracts. This differs from the approach seen in traditional smart contract account “module” systems, which grant full account authority over every module.

• How about EIP-5792?

  The Delegator Toolkit supports a fully embedded account giving the site control of its account, and therefore, does not need any JSON-RPC interface to perform whatever actions it wants.

  Eventually, once this smart account can be imported into MetaMask (via delegation, not key sharing) and connected to traditional web3 sites, this interface will be an obvious one to support.