Microsoft Research's PDD Kit formally verifies agent-written full-stack web apps

Microsoft Research introduced PDD Kit, a research prototype that turns a developer's plain-language intent into a Verus formal specification, proves the coding agent's Rust code meets it for every input, and falls back to tests where a proof cannot reach. In a demo inside GitHub Next's Chopin, the team used PDD Kit to verify the login logic of Pet Store, a roughly 5,000-line Rust full-stack app, with the developer reviewing the intent artifact rather than the generated code line by line. PDD Kit only verifies Rust today, and its guarantees rest on six developer-approved trusted pieces, including the bcrypt password check and the two database lookups.