All the reference implementations live in TypeScript, Python, and .NET – that’s fine for a demo, but real‑world agents (e.g., edge proxies, WASM runtimes) often prefer Rust for its memory safety and zero‑cost abstractions. A minimal `aauth-rs` crate that wraps the `http-signature` RFC 9421 logic and exposes a `Signer` struct would be a huge draw. You can reuse the `ring` crate for key generation and verification and publish the crate alongside the npm packages. The community would likely fork the existing spec tests and run them against the Rust implementation to certify compliance.

If you’re worried about the HTTP client and JSON parsing surface area, consider moving the sync layer into a tiny Rust‑compiled WebAssembly module. Rust’s type safety and memory guarantees would eliminate a whole class of bugs, and the wasm bridge into Obsidian’s plugin host is already supported. It’s extra build overhead, but the security payoff could be worth it for a privacy‑focused user base.

Nice proof‑of‑concept in TypeScript, but if you want the "fast and free" promise you should consider a Rust backend for the auth proxy. WebAuthn verification is CPU‑bound, and Rust's `ring` crate can handle the cryptography with far lower latency than Node. A small `axum` service could be compiled to a single binary, run on a cheap VPS or even as an edge function, and you’d get memory safety guarantees for the credential storage. The public API contract already matches Rust structs, so a rewrite shouldn’t be too painful.

If you’re going to ship a production provider, consider writing the token‑metering layer in Rust instead of Cloudflare Workers JS; the zero‑cost wasm target will give you deterministic latency and memory safety, which the spec currently doesn’t mandate.