# Lightning Swap

> Pay a Lightning invoice with SOL, ETH, USDT or USDC. The HTTP API is a FixedFloat-compatible subset (https://ff.io/api) with HMAC-signed requests.

Every link below is raw markdown — fetch it directly, no browser needed.

## Start here

- [Agent directions: API reference](https://lightning-swap.com/api_docs.md): short; tells your agent to download the full reference with its shell
- [API reference (full)](https://lightning-swap.com/api_docs/full.md): the same content as https://lightning-swap.com/api_docs