What is wasi-auth-middleware?

Wasi Auth Middleware is a toolkit that handles user login and authentication for web apps built in Rust. Instead of writing your own login flows from scratch, you get a bundle of ready-made options: email one-time passwords, magic links, OAuth2 logins through providers like Google and GitHub, two-factor authentication with TOTP codes, and WebAuthn passkeys. It also ships with pre-built UI components so your login screens look polished out of the box. At a high level, it works as a middleware layer that sits in front of your app and intercepts incoming requests to check whether users are authenticated before letting them through. It manages sessions using JWT tokens and can plug into various storage backends, Redis, DynamoDB, SQLite, or others, so you can pick whichever fits your infrastructure. A notable technical detail is that it runs on WebAssembly, meaning the authentication logic can run in lightweight, sandboxed environments rather than requiring a traditional server runtime. The main audience is Rust developers building web applications who need a complete, flexible authentication system. A concrete use case: you are building a SaaS product and want users to log in with Google, set up two-factor authentication, and use passkeys, this project gives you all of that without stitching together a dozen different libraries. It also includes a demo app showing every auth flow wired up, which helps you see how things fit together before integrating into your own codebase. What stands out is the modular design. The project is split into focused pieces, core auth logic, trait abstractions for storage and email, UI components, OAuth2 provider presets, and the standalone proxy interceptor. You can adopt just the parts you need. The tradeoff is that it targets a relatively new WebAssembly standard and requires a recent Rust version, so it assumes some comfort with bleeding-edge tooling. The project is dual-licensed under MIT and Apache 2.0, which is standard for Rust open-source libraries and lets you use it in commercial projects.