Learn about EIP-7702

What is EIP-7702?

EIP-7702 is a breakthrough Ethereum Improvement Proposal that enhances regular user accounts (EOAs) with smart contract capabilities without requiring users to migrate to new addresses. It gives users most of the core benefits of Smart Accounts, while solving the biggest friction points associated with them.

How EIP-7702 Works

At its core, EIP-7702 introduces a new transaction type with an "authorizations" field that allows EOA owners to delegate execution to a smart contract:

1. A user signs a special authorization message from their EOA
2. This authorization is recorded on the Ethereum network
3. Future transactions to this EOA execute the smart contract's code
4. The user retains their original address, history, and assets

The delegation happens at the protocol level—there's no separate contract deployed for each user. The EOA simply functions as if it has smart contract code attached directly.

Key Benefits of EIP-7702

EIP-7702 addresses major friction points in blockchain UX:

• Eliminates Multi-Transaction Workflows: Operations that previously required multiple transactions can be combined
• Enables Flexible Gas Payments: Users can pay fees in tokens other than ETH
• Introduces Permission Management: Accounts can have sub-keys with limited access
• Preserves User Identity: Users keep their address, history, and digital assets
• Removes Migration Barriers: No need to deploy new contracts or transfer assets

Guidance for Wallet Providers

Your Role in EIP-7702

As a wallet provider, you control the EIP-7702 ecosystem. Wallet providers, not applications, manage EIP-7702 authorizations and determine which smart account implementations to delegate to.

Implementation Considerations

If you're wallet provider choosing to implement a solution for EIP-7702, use Biconomy Nexus to get best-in-class security and feature support. Nexus accounts support a wide array of standards.

By delegating to Nexus, your account will automatically become compliant with:

• ERC-4337: Account Abstraction
• ERC-7579: Modular Smart Accounts
• EIP-7702: EOA Delegations
• ERC-7779: Interoperable Delegated Accounts (no vendor lock-in)
• ERC-7710: Smart Contract Delegations Framework

Beyond this, Nexus is the most gas efficient Smart Account on the market - with benchmarks to prove it. Additionally, by leveraging the PREP deployment method, a Biconomy innovation, you can save up to 80% on the cost of Smart Account deployments.

Multichain Considerations

EIP-7702 authorizations are chain-specific by default. For multichain support:

• Consider using chain_id set to 0 for cross-chain authorizations
• Be aware this only works if the EOA has the same nonce across chains
• Plan for synchronization challenges across networks

Guidance for Application Developers

Understanding Biconomy's Companion Account Approach

Biconomy offers a seamless way to leverage EIP-7702 that makes smart account capabilities appear to come from the user's existing EOA. This works through what we call "Companion Accounts."

What is a Companion Account?

A Companion Account is simply a Nexus Account (Biconomy's smart account implementation) that's deployed by your application instead of a wallet. From the user's perspective, this account is completely invisible—they interact with your application through their existing EOA, and all the advanced features appear to come from their original account.

The Invisible Companion Flow

When a user interacts with your application using Biconomy's approach, here's what happens:

1. The user performs an action in your application through their EOA
2. Your application transfers the required funds/assets to the Companion Account using either:
   • Fusion Execution (for maximum wallet compatibility)
   • ERC-7710/7715 (for modern wallets with standards support)
3. The Companion Account processes all operations using Biconomy's execution stacks:
   • ERC-4337 (Account Abstraction standard)
   • Modular Execution Environment (MEE, Biconomy's advanced execution layer)
4. After processing, all resulting tokens/NFTs/artifacts are returned to the user's original EOA

The entire process is invisible to users—they simply see their EOA gaining the advanced capabilities of ERC-4337, ERC-7579, and Biconomy's Modular Execution Environment.

Most notably, by combining Companion Accounts with some of the implementation options mentioned below, this entire flow is permitted by the user with a single signature - making Companion Accounts truly invisible for the end user.

Implementation Options

To implement this invisible companion approach, you have two main options for how the initial transfer to the companion account happens:

Option A: ERC-7710/7715 Approach

Best for: Applications targeting modern wallets

This approach uses standardized methods for requesting permission to transfer to the companion:

• ERC-7710 provides a standard interface for smart contracts to delegate permissions
• ERC-7715 introduces a JSON-RPC method (wallet_grantPermissions) for requesting permissions
• Works with wallets that support these newer standards

Learn More: Biconomy Docs: Implementing ERC-7710/7715 for Companions

Option B: Fusion Execution

Best for: Maximum wallet compatibility

Biconomy's fallback mechanism that works with any wallet:

• Repurposes fields in regular transactions
• Works without requiring wallet upgrades
• Enables complex operations even with basic wallets

Option C: Automatic Detection with AbstractJS

Best for: Applications wanting the simplest integration

Let Biconomy's SDK handle the complexity:

• AbstractJS automatically detects wallet capabilities
• Uses ERC-7710/7715 when available
• Falls back to Fusion Execution when needed
• Manages the entire companion lifecycle transparently

ERC-5792 for Simple Batching

For simple batching scenarios, you can also use the ERC-5792 approach instead of deploying a companion:

• Uses wallet_sendCalls JSON-RPC method
• Applications send multiple function calls to the wallet
• The wallet bundles these calls into a sequence
• Best for straightforward operations like token approval and swapping

When to choose this: When you only need basic transaction batching and your users have wallets supporting this method.

Biconomy's EIP-7702 Stack

AbstractJS: Your Universal Interface

AbstractJS is Biconomy's comprehensive TypeScript SDK that simplifies EIP-7702 integration by:

• Detecting wallet capabilities automatically
• Managing invisible companion account deployment
• Handling transfers to the companion using the optimal method
• Executing operations through Biconomy's execution stacks
• Returning assets to the user's EOA
• Creating a seamless, wallet-agnostic experience

Learn More: Biconomy Docs: Getting Started with AbstractJS

Nexus Account: The Smart Account Powering Companions

Nexus Account is Biconomy's modular smart account implementation that powers companion accounts:

• Fully compatible with EIP-7702
• Modular architecture for customizable features
• Supports ERC-4337 and ERC-7579 standards
• Enables advanced execution through Biconomy's MEE
• Operates invisibly in the background while the user interacts with their EOA

Learn More: Biconomy Docs: Nexus Account Overview

Biconomy Execution Environments

Once assets are in the companion account, they're processed through Biconomy's execution stacks:

ERC-4337 Stack

• Standard compliant account abstraction
• Bundler network for efficient transaction handling
• Compatible with most EVM chains

Modular Execution Environment (MEE)

• Advanced execution layer for complex operations
• Support for cross-chain transactions
• Intent-based execution capabilities
• Rich programmable transaction flows

These execution stacks operate behind the scenes, processing transactions through the companion while making it appear as if the EOA has gained these capabilities.

Implementation Strategy Guide

For Applications Just Getting Started

• Integrate the SDK to handle all complexity
• It will manage the invisible companion deployment, transfers, and execution automatically
• Begin with transaction batching, the most universally useful feature
• Add gas sponsorship for key user actions to reduce friction
• Introduce permission management for enhanced security
• Implement cross-chain operations if your application needs them

Looking Forward

EIP-7702 represents a significant step in blockchain UX evolution, and Biconomy's invisible companion approach takes it even further. By making smart account capabilities appear to come directly from users' existing EOAs, we create a truly seamless experience that preserves their identity while unlocking powerful new features.

As wallets implement EIP-7702 and related standards, applications using Biconomy's stack will be well-positioned to offer superior user experiences that work consistently across all wallet types.