Exploring the EVM Differences on Abstract Chain: What Developers Need to Know

Abstract Chain, built on zkSync's zkStack, offers an EVM-compatible environment that brings scalability and efficiency to blockchain development. However, it's crucial for developers to understand the key differences between Abstract's environment and the standard Ethereum Virtual Machine (EVM). This guide explores these differences and their implications for smart contract development.

Abstract's EVM Compatibility: An Overview

• Abstract Chain uses zkSync's zkStack VM
• EVM-compatible but not EVM-equivalent
• Most Ethereum smart contracts work seamlessly
• Some contracts may require modifications

Key Differences in EVM Instructions

Several EVM instructions behave differently on Abstract:

1. CREATE
2. CREATE2
3. CALL
4. STATICCALL
5. DELEGATECALL

Impact: These differences affect contract deployment and execution, especially in complex dApps.

Best Practice: Review and test contracts thoroughly, particularly those heavily using these instructions.

Nonce Management on Abstract

Abstract introduces a unique approach to nonces:

1. Transaction nonce: Used for validation
2. Deployment nonce: Used for contract creation

Key Differences:

• Allows multiple transactions with a single nonce value
• Enables contracts to deploy multiple other contracts without nonce conflicts

Advantages:

• Improved transaction throughput
• Enhanced contract deployment efficiency

Developer Consideration: Understand Abstract's nonce handling, especially when porting Ethereum contracts.

Precompiles: Supported and Unsupported

Supported precompiles on Abstract:

• ecrecover
• keccak256
• sha256
• ecadd
• ecmul

Note: Some EVM precompiles (e.g., pairings and RSA) are not currently available.

Impact: May affect projects relying on specific cryptographic functions (e.g., zk-SNARK-based applications).

Future Outlook: Abstract prioritizes implementing additional precompiles.

Gas Consideration: Gas costs and behavior may differ when invoked via delegatecall.

Account Abstraction on Abstract

Abstract's account abstraction (AA) differs significantly from Ethereum's EIP 4337:

1. Integrated at the protocol level
2. All accounts (including EOAs) behave like smart contract accounts
3. Unified transaction processing flow
4. Single mempool for all account types
5. Streamlined bundling and processing by the Operator

Key Features:

• Paymaster support across all account types
• Unified approach simplifies transaction management
• Enhanced network efficiency

Developer Opportunities: Explore innovative use cases and funding models leveraging Abstract's AA implementation.

Best Practices for Developers on Abstract Chain

1. Thorough Testing: Extensively test contracts, especially those using modified EVM instructions.
2. Nonce Awareness: Familiarize yourself with Abstract's dual nonce system for optimal transaction and deployment strategies.
3. Precompile Adaptation: Be prepared to adapt contracts that rely on unsupported precompiles.
4. Leverage Account Abstraction: Explore the unique features of Abstract's AA to enhance user experience and contract functionality.
5. Stay Informed: Keep up with Abstract's documentation and updates as the platform continues to evolve.

Conclusion

Abstract Chain offers a powerful alternative to Ethereum's Layer 1, combining EVM compatibility with unique optimizations. By understanding and adapting to the differences in EVM instructions, nonce management, precompiles, and account abstraction, developers can fully leverage Abstract's capabilities.

Whether you're migrating existing Ethereum projects or starting fresh on Abstract, this knowledge will be crucial for building efficient, scalable, and secure decentralized applications. As Abstract continues to evolve, staying informed about these differences will ensure a smooth and successful development experience in this innovative blockchain environment.