claude-dev-suite Fedimint
Open-source protocol for federated Chaumian e-cash mints integrated with Lightning Network. Each "federation" of trusted guardians (typically 3-15 entities) collectively manages funds.
Repos: github.com/fedimint/fedimint (Rust).
Concept
- Users deposit BTC (via on-chain or Lightning) → receive Chaumian e-cash notes signed blindly by guardians.
- Notes are bearer instruments (whoever holds them owns them).
- Spending: present notes to mint, get new notes (preventing double-spend).
- Withdrawal: redeem notes for BTC (LN gateway / on-chain).
Why federated
Single-mint Chaumian e-cash (e.g., Cashu) → trust one operator. Fedimint distributes trust among guardians:
- ~67% (2-of-3, 4-of-5, etc.) threshold for any guardian action.
- Fewer than threshold cannot withdraw funds.
Use cases: communities, geographies, organizations (church, town, DAO, etc.).
Privacy via blind signatures
Mint signs notes blindly — guardians don't see what they're signing or who is depositing. Privacy properties:
- Mint can't link deposits to withdrawals.
- Users have within-mint privacy.
- Cross-user payments via passing notes — no chain footprint.
Lightning gateway
Each federation runs a gateway: a Lightning node that bridges between Lightning and Fedimint:
- Pay LN invoice from Fedimint → gateway settles via LN.
- Receive on LN → gateway issues fresh notes to Fedimint user.
Gateway is operationally trusted but economically bonded — malicious gateway loses bond.
Fedi (mobile app)
- Mobile + web app for Fedimint federations.
- Native multi-mint support.
- Lightning + on-chain via federation gateway.
- Multi-sig guardian creation flow ("G-bot" assistant).
Components
- fedimintd — guardian daemon.
- fedimint-cli — admin CLI.
- fedimint-lnv2-client — gateway integration.
- Fedi mobile app.
Compared to Cashu
| Aspect | Fedimint | Cashu |
|---|---|---|
| Custody | Federated multisig | Single mint operator |
| Trust | Threshold | Single |
| Setup complexity | Higher (require guardians) | Lower (run mint solo) |
| Maturity | Beta production | Beta production (NUTs spec evolving) |
| Mobile | Fedi app | Many wallets |
Use cases
- Community banking in rural / underbanked areas.
- Family / org wallet with shared custody.
- Privacy-first payments without on-chain footprint.
Limitations
- Federation trust — k-of-n collude → funds risk.
- Mint requires operator unlike fully decentralized chains.
- Notes can be reused if owner not careful (bearer instrument).
- Backup is harder — losing notes = losing funds (unlike seed recovery for HD wallet).
Recent (2025-2026)
- Fedi multi-sig guardian creation simplified via G-bot UI.
- Stealth-to-scale milestone: federations expanding from <10 to hundreds of communities.