Definition
Fedimint is an open-source protocol for running federated Chaumian ecash mints on Bitcoin. It lets a community establish a trust-minimized, privacy-preserving custody solution operated not by one party but by a group of "guardians." Users deposit bitcoin into the federation and receive blind-signed ecash notes that are 1:1 claims against those deposits, redeemable on-chain or over Lightning.
The guardian model
Where a single-operator design like Cashu relies on one mint, Fedimint distributes custody across a threshold of guardians — typically four or more, each running their own server. A quorum must sign off on deposits and withdrawals, so user funds sit in a guardian multisignature wallet rather than under one operator's control. Guardians also assist with backup and account recovery. This spreads counterparty risk and makes a single dishonest or offline guardian non-fatal.
Privacy and scaling
Inside the federation, members transact in ecash notes whose blinded signatures hide who is paying whom; the guardians cannot see internal balances or transaction graphs. Because everyday payments happen as ecash rather than as separate on-chain or Lightning transactions, Fedimint also functions as a scaling layer, batching a community's activity and only touching the base chain on deposit and withdrawal.
Fedimint pairs federated custody with cash-like privacy, occupying a middle ground between full self-custody and trusting a single mint. It is often used alongside the Lightning Network and other sovereignty tools; for context on the underlying primitive, see blinded signature.
In Simple Terms
Fedimint is an open-source protocol for running federated Chaumian ecash mints on Bitcoin. It lets a community establish a trust-minimized, privacy-preserving custody solution operated not…