Show HN: 1seed – Derive all your crypto keys from a single seed

I built 1seed because I was tired of managing separate SSH keys, age keys, and signing keys across machines.

Also something about brain wallets is romantic to me, admittedly.

One seed derives everything deterministically: SSH keys, age encryption keys, Ed25519 signing keys, and site-specific passwords. Same seed + same realm = same keys, always.

Storage is automatic: tries OS keychain (macOS Keychain, Linux Secret Service, Windows Credential Manager), falls back to ~/.1seed if unavailable. No config files.

Written in Rust. MIT licensed.

Use cases: - Same SSH key across all your machines without copying files - Deterministic age encryption keys for secrets management - Password derivation with rotation (increment counter when compromised) - BIP39 mnemonic generation (with appropriate warnings)

Not a replacement for hardware keys on high-value targets, but solid for everyday dev work and personal infra.

The fallback behavior means it works on headless servers without a keyring daemon, which was the main pain point that led me to write it.