Before PDD Kit, Microsoft Research says formal proofs required specialists and unfamiliar languages.
Now PDD Kit turns plain intent into Verus specs and proves Rust code for every input.
The kit also lists a standalone project page on GitHub Next according to the GitHub Next site.
The publication tests the flow inside GitHub Next Chopin on Pet Store, a 5,000-line Rust app according to the post.
The demo app uses Axum, SQLite and Leptos compiled to WebAssembly according to the post.
The team targeted login logic in backend/src/handlers/auth.rs with two rules about passwords and admin tokens.
PDD Kit asked decision cards to lock whether correct passwords must always produce tokens.
It then proved a new async login_flow function and left six wrappers trusted with explicit contracts according to the post.
Those wrappers cover bcrypt verify, sqlx lookups, jsonwebtoken signing, clock expiry and error mapping.
Empirical tests cover what proofs cannot, such as UI, timing and unwritten requirements.
The next public airing is Microsoft at SOSP 2026, listed in the post.
