⚡ Account Abstraction (ERC-4337 + zkSync Era)

A hands-on implementation of Account Abstraction (ERC-4337) using smart contract wallets, EntryPoint mechanics, and off-chain scripting.

This project explores how UserOperations are constructed, signed, and executed, replacing traditional EOAs with programmable smart accounts.

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🧠 Overview

This repository covers the full Account Abstraction lifecycle:

• Smart Contract Wallet deployment
• ERC-4337 EntryPoint interaction
• UserOperation construction & execution
• Off-chain scripting using TypeScript
• Cross-chain compatibility (Ethereum + zkSync Era)

The focus is on the execution flow and scripting layer, which is critical in real-world AA systems.

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⚙️ Core Concepts

🔹 Account Abstraction (ERC-4337)

• Removes dependency on EOAs
• Introduces UserOperation instead of traditional transactions
• Uses EntryPoint contract for execution
• Enables gas abstraction and programmable accounts

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🔹 UserOperation Lifecycle

1. Construct UserOperation (off-chain)
2. Sign with Smart Account owner
3. Submit to EntryPoint
4. EntryPoint validates:
   • Signature
   • Nonce
   • Gas limits
5. Smart Wallet executes transaction

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🏗️ System Architecture

flowchart LR
    U[User]
    S[TypeScript Scripts]
    OP[UserOperation]
    EP[EntryPoint]
    SW[Smart Wallet]
    EX[Execution]

    U --> S
    S --> OP
    OP --> EP
    EP --> SW
    SW --> EX

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🔍 Flow Explanation

• Scripts (off-chain) → build & sign UserOperations
• EntryPoint → validates and routes execution
• Smart Wallet → executes logic on-chain

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🔩 Core Components

🧾 Smart Contract Wallets

• Replace EOAs with programmable accounts
• Execute transactions via EntryPoint
• Compatible with Ethereum & zkSync Era

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🧠 EntryPoint (ERC-4337 Core)

• Handles:

  • Validation
  • Execution

• Central coordination layer for UserOperations

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🧪 Interaction Scripts (TypeScript)

Main focus of the project.

Scripts handle:

• Constructing UserOperations
• Encoding calldata
• Signing operations
• Sending operations to EntryPoint
• Simulating bundler behavior

⚠️ Most complexity in Account Abstraction lives off-chain — this layer is critical.

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🚧 Current Work (Active Development)

🔹 zkSync Era Deployment Challenge

Deploying ZkMinimal.sol using TypeScript scripts due to:

• Limitations with Foundry scripting on zkSync Era

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🔹 In Progress

• Custom deployment scripts (TypeScript)
• Encryption script for private key handling
• Sending AA transaction flow (sendUserOp)
• zkSync-specific execution understanding

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▶️ Script Usage

Install Dependencies

yarn install

Compile Contracts

forge build

Deploy Contracts (Foundry)

forge script script/Deploy.s.sol \
  --rpc-url $RPC_URL \
  --private-key $PRIVATE_KEY \
  --broadcast

Deploy via TypeScript (zkSync-compatible)

yarn deploy
# or
npx ts-node typescript-scripts/deploy.ts

Create UserOperation

npx ts-node typescript-scripts/createUserOp.ts

Send UserOperation

npx ts-node typescript-scripts/sendUserOp.ts

Encrypt Private Key

npx ts-node typescript-scripts/EncryptKey.ts

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🌐 Supported Networks

• Ethereum (ERC-4337)
• zkSync Era

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🧪 Tech Stack

• Solidity
• ERC-4337
• Foundry
• TypeScript / JavaScript
• ethers.js / viem
• zkSync SDK

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📂 Project Structure

/contracts
  ├── SmartWallet.sol
  ├── ZkMinimal.sol
  └── (future) Paymaster.sol

/script
  ├── Deploy.s.sol
  ├── Interactions.s.sol

/typescript-scripts
  ├── deploy.ts
  ├── createUserOp.ts
  ├── sendUserOp.ts
  ├── EncryptKey.ts

/test
  ├── SmartWallet.t.sol

/lib
  └── EntryPoint

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📌 Key Learnings

• ERC-4337 architecture
• Full UserOperation lifecycle
• EntryPoint validation and execution
• Importance of off-chain infrastructure
• zkSync vs Ethereum differences
• Smart wallet design patterns

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🧭 Roadmap

• Paymaster (gas sponsorship)
• Session Keys (delegated permissions)
• Bundler simulation improvements
• zkSync deployment pipeline
• Optional frontend

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💡 Purpose

To build a solid engineering understanding of:

• Smart contract wallets
• Gas abstraction
• Modular account systems
• Off-chain + on-chain interaction

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📎 Notes

This project is part of a deeper exploration into:

• Account Abstraction
• Smart Wallet Infrastructure
• zkSync ecosystem

Ongoing improvements will focus on scripting, deployment, and architecture.

That’s what makes it hit *professional level*.