cred-rs

Named secrets in the operating system's native credential vault, built entirely on the Rust standard library. Zero dependencies: no keyring crate tree, no libc/windows/security-framework. The OS boundary is this crate's own small, audited extern blocks.

One concern: bytes under names, in the vault the OS already guards.

cred::set("myapp", "api-key", b"sk-example-123")?;
cred::get("myapp", "api-key")?;        // Some(b"sk-example-123".to_vec())
cred::entries("myapp")?;               // ["api-key"]        (Windows)
cred::delete("myapp", "api-key")?;     // true
# std::io::Result::Ok(())

Secrets are namespaced by a service string and identified by a name within it. Size is capped at MAX_SECRET (2560 bytes, the Windows generic-credential limit, adopted everywhere for portability): this is a key/token store, not a blob store.

Platform support, stated honestly

OS	Backend	Status
Windows	Credential Manager (CredWriteW/CredReadW/CredDeleteW/CredEnumerateW, advapi32)	tested against the real vault
macOS	Keychain (SecKeychain* generic-password C API, deprecated by Apple but stable; a fraction of the SecItem* FFI surface)	compile-checked; no macOS runner yet, so treat as beta
Linux / other Unix	Secret Service requires a D-Bus client: planned, not faked	every call returns ErrorKind::Unsupported

Deliberately no file fallback. A platform without a supported vault gets an honest Unsupported error. Silently writing secrets to plaintext files would betray exactly the promise this crate exists to keep. entries() is Windows-only for now (Keychain enumeration is a much larger FFI surface); callers needing portable listing keep their own index entry.

What's deliberately out of scope

• Key formats and vendor semantics: it stores bytes; what they mean is the caller's business (the akey app layers Anthropic-specific profiles on top).
• Networking, caching, encryption of our own: the OS vault is the security boundary; we add nothing beside it.

Correctness

On Windows the integration tests run against the real Credential Manager: set/get/delete round-trip, overwrite, a full 0–255 binary secret, the exact MAX_SECRET boundary, service-scoped enumeration, each in a unique per-process namespace, cleaned up afterward. On non-macOS Unix the tests assert the Unsupported contract (and that input validation still fires first with InvalidInput). Input validation rejects empty names, /, NUL, and control characters before anything reaches the OS.

Development

python dev.py check   # zero-dependency guard + cargo test (the pre-push gate)
python dev.py test    # cargo test
python dev.py fmt     # cargo fmt --check
python dev.py guard   # zero-dependency guard

dev.py is a stdlib-only runner, so python dev.py check is the same one-command local gate used across every nativelite package. The guard fails if Cargo.toml declares any dependency, runtime, build, or dev.