This is the source of the official Boltz Backend powering swaps at boltz.exchange. It enables non-custodial swaps between different Bitcoin layers. Boltz Backend exposes a RESTful HTTP API that can be used to query information like supported pairs as well as to create and monitor swaps.
Don't integrate the API directly. Use an official SDK or client library. They handle the cryptography, the swap state machine, and fund-recovery edge cases for you. See Clients, SDKs & Libraries.
See the Boltz API documentation.