Fedimint

• Name: Fedimint
• URL: https://fedimint.org/
• Category: Bitcoin community custody infrastructure / federated e-cash protocol / privacy-preserving payments middleware
• Tags: bitcoin-ecosystem
• Summary: Fedimint is the protocol anchor in this community-custody lane: an open-source framework for federated Bitcoin applications whose main live use case is shared custody plus private e-cash payments. Its official website, guardian docs, technical reference, SDK docs, and public GitHub surfaces show a layered system spanning threshold Bitcoin custody, blind-signature-style e-cash issuance, Lightning gateway integration, modular federation software, and wallet/app SDKs, so it belongs under community-custody and privacy-preserving payments infrastructure rather than in a generic wallet bucket.
• What it does:
  • Lets communities form federations of trusted guardians that jointly custody Bitcoin in threshold multisig and run the Fedimint protocol together
  • Issues privacy-preserving e-cash inside those federations so users can transact privately and instantly within the federation environment
  • Connects federations to Bitcoin and Lightning through built-in wallet and Lightning modules plus a separate gateway role for broader Lightning interoperability
  • Exposes a modular architecture where ecash, wallet, Lightning, and metadata functions are implemented as modules and additional modules can be added at federation setup
  • Provides client libraries, a WebAssembly-capable SDK, CLI tools, and wallet integrations so apps can join federations, manage balances, and send/receive ecash and Lightning payments
  • Publishes an implementation-heavy Rust codebase and technical reference documentation that make the protocol and deployment surface unusually transparent for an early Bitcoin payments stack
• Key claims:
  • The official homepage describes Fedimint as “open-source federated e-cash for Bitcoin, built for privacy and scale” and highlights a three-sided surface for users, guardians, and builders
  • The user introduction says Fedimint is a “community custody protocol” run by trusted community members that provides privacy, scalability, and extensibility without accounts or KYC
  • The guardian docs make the trust model unusually explicit: guardians are expected to be known community members who hold one key each in a multi-signature wallet and operate Fedimint nodes for the people they serve
  • The federation-architecture docs explain that guardians coordinate with AlephBFT consensus, hold Bitcoin in threshold multisig, and rely on ecash, wallet, Lightning, and meta modules as the core protocol building blocks
  • The GitHub README broadens the frame from e-cash mint to a “module based system for building federated applications,” while also stating that Bitcoin, Lightning, and Chaumian ecash ship as the three default modules
  • The SDK docs show that Fedimint is trying to become app infrastructure, not just federation software, by exposing Rust/WebAssembly client components for federation joining, ecash payments, Lightning payments, and wallet-state management
• Whitepaper: No single canonical Fedimint whitepaper or litepaper surfaced in this pass. The clearest current source of truth is the official website, guardian/user docs, technical reference documentation, SDK docs, and public GitHub repositories; see ../whitepapers/fedimint-primary-sources-2026-04-28.md.
• Sources:
  • https://fedimint.org/
  • https://fedimint.org/users/intro
  • https://fedimint.org/guardians/intro
  • https://fedimint.org/guardians/how-federations-work
  • https://docs.fedimint.org/
  • https://sdk.fedimint.org/
  • https://github.com/fedimint/fedimint
  • https://github.com/fedimint

Internal linkages

• Best comparison point: cashu.

• Keep application-shell comparisons like Fedi downstream; this note should not spend scarce linkage budget promoting weaker wrappers.

• Last reviewed: 2026-06-02 UTC