How are funds sent within & across federations?

Funds can be sent into and out of Fedimint federations, including from one federation to another, on the Bitcoin blockchain or via the Lightning network. While you can send funds from any federation wallet to an on-chain address, whether a federation supports receiving funds on chain is case by case.

Transactions within the same federation are kept anonymous by leveraging Chaumian eCash, which allows for the creation, transacting, and redemption of notes that represent blinded claims on an equivalent amount of bitcoin. eCash notes are redeemed from the mint for bitcoin before funds are transferred out.