Tools · L3 — ecash & scaling layers

Fedimint

Federated Bitcoin custody plus Chaumian ecash — a guardian federation holds the coins under threshold security while issuing private, Lightning-interoperable tokens.

What it is

Fedimint is an open-source, module-based protocol for running federated Chaumian ecash mints. Instead of one operator custodying the backing Bitcoin (as in single-mint Cashu), a federation of guardians — typically 4–13 — jointly custodies it under threshold signatures: no single guardian can defect or be compromised in isolation. The federation issues private Chaumian ecash and interoperates with the wider Lightning Network through gateway nodes. It ships with Bitcoin, Lightning, and ecash modules.

It is the heavier-trust, higher-robustness option at the L3 bearer-ecash layer: more coordination overhead than Cashu, but no single point of custodial failure.

When to use it

• Community or institutional custody where distributing trust across multiple operators matters.
• Bearer-ecash deployments that want better defection-resistance than a single mint.
• Settings where you can stand up and operate a federation of guardians, not just a lone mint.

Dependencies

A Fedimint client and a federation to join — trust is distributed across its guardians under threshold security rather than a lone operator — plus a Lightning gateway for ecash↔Lightning. Running your own federation means coordinating multiple guardian operators.

Quick start

Clone github.com/fedimint/fedimint and follow the developer docs at docs.fedimint.org to run a federation or build against the modules; the Fedi operator docs cover running guardians in production. Check the repo’s releases page for the current version and per-module maturity before deploying.

Gotchas

• Trust is reduced, not eliminated: a majority-malicious or colluding guardian set can still compromise funds. The model assumes an honest threshold. For how to vet a specific federation (solvency proofs, guardian track record, ratings/uptime), see Evaluating an ecash mint.
• Running a federation means coordinating multiple guardian operators; Lightning gateways that bridge ecash ↔ Lightning need their own liquidity.
• Some features have shipped beta- or Signet-only in recent releases — confirm maturity per module before relying on it.