Most crypto APIs require signup, email verification, and API key management. This guide lists the free APIs that don't — just make a request and get data.

TL;DR​

swapapi is a drop-in alternative to 1inch's Swap API. No API key, no SDK, no account. One GET request returns the same calldata you're used to — across 46 EVM chains instead of ~10.

TL;DR​

You can swap any ERC-20 token on 46 EVM chains with a single GET request to swapapi. No API key, no SDK, no account. The response includes executable calldata ready for on-chain submission.

TL;DR​

Price impact measures how much your trade moves the market price. Slippage is the maximum deviation you'll accept between quoted and executed price. swapapi returns both values so you can protect users from unfavorable trades.

TL;DR: Swap USDC, USDT, and DAI across 46 EVM chains with a single GET request. No API key required. Watch out for decimal differences on BSC and Rootstock.

swapapi supports 46 EVM-compatible blockchains. Use the chain ID in your API requests.

TL;DR​

swapapi is the only DEX aggregator API that AI agents can use without API keys. A single GET request returns executable calldata — no authentication, no SDK, no state management.

TL;DR​

A DEX aggregator searches multiple decentralized exchanges simultaneously to find the best swap rate for a token trade. Instead of checking Uniswap, SushiSwap, and Curve individually, a DEX aggregator checks all of them in one request and routes your trade through the optimal path.

TL;DR​

Every major DEX aggregator API — 1inch, 0x, Paraswap, Li.Fi — requires an API key. swapapi doesn't. It's free, requires no signup, and works with a single GET request. Here's why.