identity.json previously stored `privKeyHex` and `nsec` as plaintext fields.
0600 file perms keep other OS users out, but not another app running as the
same user — and that is the threat model the CLI actually cares about.
Introduce a SecretStore indirection:
* identity.json now persists only the public parts plus a typed
`secret: IdentitySecret` envelope (keychain | ncryptsec | plaintext).
* macOS uses `/usr/bin/security` (Keychain ACLs bind the item to the binary
that stored it, so other same-user apps need user consent).
* Linux uses `secret-tool` if a Secret Service is running on the session
D-Bus; the gain there is at-rest encryption while the keyring is locked.
* On any platform without a keychain, auto falls back to NIP-49
(scrypt + XChaCha20) with the passphrase read from --passphrase-file,
then $AMY_PASSPHRASE, then a TTY prompt. Another same-user app can read
the blob but cannot decrypt it without the passphrase.
* `--secret-backend=plaintext` is an explicit opt-in for dev scripts and
the interop test harness.
Legacy identity.json files that still carry top-level privKeyHex/nsec are
read transparently and auto-migrate on the next save.
whoami, `create` / `login` existence checks, and init-re-run now use a
metadata-only load path so they do not trigger a keychain prompt or ask
for a passphrase just to echo the npub.
Tests: cli/tests/ setups wire --secret-backend=plaintext through the amy_a
/ amy_d wrappers so headless CI runs do not stall on a TTY passphrase
prompt.
https://claude.ai/code/session_01SqdMfLdXvb3GskFLcEj739
Claude
b507cb5986