Introduction

What is OP-20

The OP-20 standard defines a comprehensive interface for fungible tokens on OP_NET, incorporating lessons learned from years of ERC-20 usage and billions of dollars in lost tokens. This standard introduces mandatory safe transfers with receiver validation, delta-based allowance modifications to prevent exploits, and signature-based approvals using Schnorr signatures.

Creating a New Standard

The ERC20 standard revolutionized blockchain tokens but revealed critical weaknesses through real-world usage:

• Billions in Lost Tokens: Users accidentally sending tokens to contracts that cannot process them.
• Front-Running Vulnerabilities: The approval race condition enabling double-spend attacks.
• Inefficient Data Retrieval: Multiple RPC calls needed for basic token information.
• Missing Features: No native burn, no receiver notifications.

OP-20 addresses these issues while introducing OP_NET specific optimizations:

• Contracts must acknowledge token transfers.
• Schnorr signature integration for cryptographic operations.
• Native support for the OP_NET memory model and storage pointers.
• Built-in domain separation using OP_NET's chain and protocol identifiers.
• Optimized for AssemblyScript/WebAssembly execution environment.

Comparison with ERC20