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Account Kit

Account Kit is a framework designed to embed smart accounts in web3 applications. It includes a set of tools such as Signer integrations, Gas Manager and Bundler utilities that unlock features such as gas sponsorship, batched transactions and email/social login. With its user-friendly suite of SDKs, known as aa-sdk, Account Kit makes it easy to deploy smart accounts, manage UserOperations, and handle gas sponsorship, streamlining the entire process with minimal coding effort.


A network participant in the ERC-4337 standard that collects and submits UserOperations (UOs) to the blockchain, handling the associated gas fees, in exchange for payment during UO processing either directly from the user or from a Paymaster. Alchemy’s implementation of a bundler is called Rundler. It is written in Rust and designed to achieve high performance and reliability.


Built on top of viem, we have built our own Client extended with custom functionality as a BundlerClient and SmartAccountClient compliant to EIP-4337 and EIP-6900 standards. Client, in general, is an intermediary or connector that enables interactions between client applications and your SmartAccount (either LightAccount or ModularAccount) or the Bundler.


A standardized smart contract that acts as the primary gateway for processing UserOperations (UOs) on the blockchain. It receives bundled UOs from Bundlers and verifies and executes these operations according to predefined rules, ensuring security and adherence to user-specified conditions. EntryPoint contract is a singleton contract to execute bundles of UserOperations. Bundlers whitelist the supported EntryPoint.


A standard authored by the Ethereum Foundation for account abstraction, establishing a uniform interface for all smart accounts. This standard also outlines the roles and functionalities of Bundlers, Paymasters, and EntryPoint. Reference:


A standard designed for verifying signatures from smart accounts that haven't been deployed yet. It is important for account abstraction, allowing decentralized applications (dApps) to authenticate user signatures even before the user's smart account is deployed. The deployment of these accounts typically occurs during the user's first transaction, making ERC-6492 essential for early interaction verification between users and dApps.


A standard for modular accounts authored by Alchemy and Yoav (one of the authors of ERC-4337) from the Ethereum Foundation. It defines standard interfaces for Modular Accounts (Modular Accounts) capable of supporting all standard-conformant Plugins.

Gas Manager

Gas Manager is the Alchemy’s Paymaster service. With robust security and customizability, Alchemy Gas Manager allows you to easily and securely sponsor the gas fees for users of your applications. Gas Managers authenticate transactions and ensure payments are carried out only when specific conditions are fulfilled, significantly reducing the chances of fraud and errors. Additionally, Gas Managers allow you to set granular rules for sponsoring your user's gas fees, so you can determine precisely when and how the gas fees will be sponsored. Head over to Gas Manager documentation to learn more.

Light Account

Light Account is a collection of lightweight, production-ready ERC-4337 smart accounts developed by Alchemy. It builds on top of Ethereum Foundation's canonical SimpleAccount to add key improvements such as ownership transfers, multiple owners, ERC-1271 signature support, and gas optimizations. It has been audited multiple times by Quantstamp.

Magic Link Authentication

A magic link is a one-time use link sent to a user during the authentication process. After entering their username, the user is sent a URL, either to the user's email address or their mobile phone via text. The user clicks to authenticate themselves without entering a password, and for some, this might seem like "magic," thus the name. Magic links are attractive because it is a simple way to remove the need for a customer to generate and remember a password from the process.

Modular Account

A type of smart account enabled by the ERC-6900 standard and characterized by its modular structure. This structure segments different functionalities of the account into distinct, independently upgradeable modules or plugins. Each plugin can have specific functions such as validation, execution, or hooks, enabling the smart account to extend its capabilities or modify its behavior without altering the core account logic. Modular Accounts enhance the flexibility, upgradeability, and interoperability of ERC-4337 smart accounts. Modular Account contracts have been audited by both Spearbit and Quantstamp.


Passkeys are a safer and easier alternative to passwords. With passkeys, users can sign in to apps and websites with a biometric sensor (such as a fingerprint or facial recognition), PIN, or pattern, freeing them from having to remember and manage passwords.


A Paymaster is an on-chain contract that allows an entity to sponsor the gas fees for another entity. It can be used by dapps or companies to abstract away the concept of gas from their users. This significantly enhances the UX of dApps and can help onboard the next wave of Web3 users.


A module for ERC-6900 smart contract accounts, plugins are deployed smart contracts that host any amount of the EIP-6900 modular functions: execution functions, validation functions, or hooks. These plugins ensure modularity, upgradeability, and adherence to standardized interfaces.


A service or application that manages the private key and signs either arbitrary messages or structured data objects such as UserOperations or Transactions before sending to the network. Types of signers include:

  • Custodial: Managed by a third party, it holds and autonomously uses the private key for transactions, necessitating complete user trust.
  • Non-custodial: While a third party manages the private key, user involvement is required for signing transactions. Examples: Metamask.
  • MPC (Multi-Party Computation): Partial or complete key shares are managed by third parties, but user participation is needed for transaction signatures. Examples: Privy, Portal, Fireblocks, Fordefi.
  • Decentralized MPC: Operated by a decentralized network, it manages key shares and requires node consensus for transaction signatures. Examples: Lit, Web3auth, 0xpass.

Smart Contract Account

A Smart Contract Account (SCA), or smart account in short, is an individual on-chain account located at a public address where an ERC-4337 compatible smart account contract is deployed to. This address is controlled by one or more owners of the smart contract account. The aa-sdk supports different smart account implementations such as Modular Account, Light Account, or Simple Account. You can also add your own account implementation in aa-sdk.


Transactions in blockchain are cryptographically signed data messages that contain a set of instructions. These instructions can be interpreted to send native tokens from one account to another or interact with a smart contract deployed on the blockchain. A Transaction usually consists of the following parameters: nonce, gasPrice, gasLimit, to, value, data, v, r, s. Ethereum and other EVM blockchains have evolved to allow other transaction standards such as EIP-1559, to allow more predictable gas fees and a more efficient transaction market.

Transaction Calldata

Transaction calldata refers to the data passed along with a transaction that allows accounts to send messages to other entities or interact with smart contracts. When calling smart contracts on-chain (either from an EOA or another contract), the calldata is the encoded data within the Transaction containing the input parameters (or arguments) of the function being called on the contract.

User Operation

User Operations are pseudo-transaction objects introduced by the ERC-4337 standard that are issued to execute actions via a smart account. It encapsulates the intended actions or transactions of the user, which are executed on-chain by a Bundler through an EntryPoint contract on different EVM chains.


Wallets are applications that give you control over your account. Like your physical wallet, it contains everything you need to prove your identity and handle your assets. Your wallet allows you to sign in to applications, read your balance, send transactions, and verify your identity. Your wallet is a tool for interacting with your account, which can be either an Externally-Owned Account (EOA) or SmartContractAccount. Conventionally, wallets used to interact with SmartContractAccounts are called Smart Contract Wallets, while wallets used to interact with Externally-owned accounts (EOA) are called EOA Wallets.

Wallet-as-a-Service (WaaS)

Also called a key management service (KMS). WaaS is an infrastructure-as-a-service provider that stores private key material. A WaaS provider would be classified under one of the signer custody types.