Introduction to SatSigner

Privacy-first Bitcoin signer with complete UTXO control. Built for users who demand full sovereignty over their Bitcoin.

What is SatSigner?

SatSigner is a comprehensive Bitcoin wallet application built for users who demand complete control over their Bitcoin. Built on the Bitcoin Development Kit (BDK), SatSigner provides native support for single-signature, multi-signature, and watch-only accounts across mainnet, testnet, and signet networks.

SatSigner is open source and fully auditable. The codebase is available on GitHub under the MIT license.

Core mission

SatSigner focuses on user experience for everyday Bitcoin use while providing powerful features for advanced users. It enables easy movements between Bitcoin layers, enhancing the utility of your sats through:

Complete UTXO control

Visual bubble charts and detailed selection tools for granular coin management

Privacy first

No third-party tracking, encrypted storage, and privacy-enhancing features

Multi-signature support

M-of-N multisig wallets with per-cosigner PSBT tracking

Bitcoin-native terminology

Uses Bitcoin’s true language: UTXOs, transactions, signers, and sats

Built for Bitcoin sovereignty

SatSigner provides everything you need to achieve true Bitcoin sovereignty:

Full control over your coins

Every satoshi you own is represented as a UTXO (Unspent Transaction Output). SatSigner gives you complete visibility and control over each UTXO through:

• Interactive bubble charts that visualize UTXO sizes and relationships
• Manual coin selection for every transaction
• Privacy-enhancing coin selection algorithms like STONEWALL
• BIP329 labeling for comprehensive transaction and UTXO metadata

// Example: UTXO selection with privacy optimization
const { inputs, fee, privacyScore } = selectStonewallUtxos(
  utxos,
  targetAmount,
  feeRate,
  {
    minInputs: 4,
    maxInputs: 10,
    minOutputs: 2,
    maxOutputs: 4
  }
);

Security and privacy

Your keys and data are protected with:

• AES-256-CBC encryption with PIN-protected access
• PBKDF2 key derivation with 10,000 iterations
• Seed dropping capability to remove mnemonics after key extraction
• Duress PIN support for emergency scenarios
• No telemetry or tracking - your data stays on your device

Always backup your seed phrase before enabling seed dropping. Once the mnemonic is removed, you cannot recover it from the app.

Network flexibility

SatSigner supports multiple Bitcoin networks and backend options:

Networks

• Mainnet: Production Bitcoin network
• Testnet: Bitcoin test network for development
• Signet: Signature-based test network

Backends

• Electrum Protocol: Connect to any Electrum server
• Esplora API: REST API for blockchain data
• Both support Tor for private communications

Script types

All Bitcoin script versions are supported:

• P2PKH (Legacy)
• P2SH-P2WPKH (Nested SegWit)
• P2WPKH (Native SegWit)
• P2TR (Taproot)
• P2WSH (Witness Script Hash)
• P2SH-P2WSH (Nested WSH)
• P2SH (Script Hash)

Beyond Bitcoin layer 1

While SatSigner focuses on Bitcoin on-chain as the safe layer of last resort, it also supports additional Bitcoin layers:

Lightning Network integration

Connect to your own LND node via REST API to:

• Create and pay Lightning invoices
• View channel balances and status
• Manage Lightning liquidity
• Seamlessly move sats between on-chain and Lightning

eCash (Cashu) support

Private digital cash with:

• Mint management and discovery
• Token operations (receive, send, melt)
• Privacy-preserving payments
• Bearer token custody

Nostr integration

Decentralized label synchronization via Nostr protocol:

• Sync transaction labels across devices
• Encrypted Nostr DMs for secure sync
• Relay management
• Trusted device configuration

Open source ethos

SatSigner embraces open source principles:

All dependencies are open source. The entire codebase is auditable. No closed-source libraries are used for critical functionality.

Technology stack

Backend:

• Bitcoin Development Kit (BDK) via RN-BDK
• Blockstream Electrs for backend connectivity
• Photon SDK for mobile Bitcoin development
• Tor for private communications

Frontend:

• React Native with TypeScript
• Expo for cross-platform development
• Zustand for state management
• React bubble charts and D3 for visualizations

Design inspiration

SatSigner builds upon powerful features from:

• Sparrow: Clean native Bitcoin signer management
• FullyNoded: Remote full node management
• BitFeed: Beautiful blockchain visualization
• Mempool.space: Comprehensive block explorer
• Zeus: Lightning node management

Who should use SatSigner?

SatSigner is built for:

Bitcoin power users

Users who want complete control over coin selection, privacy, and UTXO management. Perfect for those who understand Bitcoin at the UTXO level and want granular control.

Privacy-conscious individuals

Anyone who values financial privacy and wants to avoid blockchain analysis. SatSigner provides tools for coin control, transaction obfuscation, and private backend connectivity.

Multi-signature coordinators

Teams and individuals managing multi-signature setups. SatSigner supports full PSBT workflows with per-cosigner tracking and air-gapped signing.

Bitcoin educators

Teachers and learners who want to understand Bitcoin’s technical details. SatSigner uses Bitcoin-native terminology and provides visual tools to understand UTXOs, transactions, and fees.

Mobile-first users

Anyone who wants a powerful Bitcoin wallet on their mobile device without sacrificing functionality. SatSigner brings desktop-class features to iOS and Android.

Getting started

Ready to take control of your Bitcoin? Follow our quickstart guide to create your first wallet, or explore the features to learn what SatSigner can do.

Quickstart

Set up SatSigner and create your first wallet in minutes

Feature overview

Explore all capabilities and features in detail

Why SatSigner?

Learn about the philosophy and design principles

Installation

Download and install SatSigner on your device