5 Best DEX APIs for Solidity Smart Contracts

Solidity accounts for roughly 65% of all smart contract deployments across EVM-compatible chains. With decentralized exchanges processing over $876 billion in spot volume in Q2 2025 alone and the DEX-to-CEX ratio climbing to 21.2% as of late 2025, integrating swap functionality directly into smart contracts is no longer optional for serious DeFi protocols. But here is the problem: on-chain routing is expensive and complex. Splitting a trade across dozens of liquidity pools, computing optimal pat