Numa Wallet: Air-gapped Signer

Numa Wallet — Bitcoin Watch-Only & Air-Gapped Signer

Your keys, your coins. No compromises.

Numa Wallet is a Bitcoin-only wallet built for self-custody. Use it as a watch-only wallet to monitor your holdings, or turn an old phone into a fully air-gapped hardware signer — no internet, no third-party servers touching your keys, no hardware purchase needed.

— WATCH-ONLY MODE —

Import your xpub, ypub, zpub, or full output descriptor to track balances and transactions in real time. Supports all major address types: Native SegWit (bech32), Taproot (bech32m), Nested SegWit, and Legacy. Build unsigned transactions (PSBTs) and exchange them with your signer via animated QR codes.

• Multiple wallets with instant switching • Full transaction history with fee and confirmation details • Receive addresses with QR codes • Replace-By-Fee (RBF) for stuck transactions • Fiat conversion in 10+ currencies • Multisig support (2-of-3 and beyond)

— SIGNER MODE —

Transform any phone into a dedicated signing device. Signer mode blocks all internet access at the code level — your seed phrase never leaves the device and never touches a network. Sign transactions by scanning QR codes from your watch-only wallet.

• 100% air-gapped — no Wi-Fi, no cellular, no Bluetooth required • BIP39 seed phrase import (12, 15, 18, 21, or 24 words) • Optional BIP39 passphrase support • Export xpub via QR for easy pairing with your watch-only wallet • Temporary signer mode — keys held in memory only, wiped on exit • PSBT exchange via animated QR (supports UR and BBQr encoding)

— SECURITY FIRST —

Your seed phrase is encrypted locally with AES-256-GCM using a key derived from your PIN via Argon2id (winner of the Password Hashing Competition) combined with a hardware-bound device key stored in the Secure Enclave. Even if someone extracts your encrypted data, they cannot decrypt it without both your PIN and the physical device.

• Argon2id key derivation (64 MiB, memory-hard — brute-force resistant) • AES-256-GCM authenticated encryption • Hardware-backed device key (Secure Enclave / Keystore) • Face ID / Touch ID for quick unlock • Auto-wipe after 5 failed PIN attempts • No analytics, no tracking, no accounts, no registration

— PRIVACY —

Numa Wallet never asks for your name, email, or phone number. There are no accounts, no cloud sync, and no telemetry. Your financial data stays on your device.

— SUPPORTED LANGUAGES —

English, Portuguese, Spanish, German, Italian.