pnpm releases version 12 with Rust-based core rewrite

The JavaScript package manager pnpm has released version 12, featuring a significant rewrite of its core implementation in Rust. This transition from TypeScript and Node.js aims to reduce startup and filesystem overhead while maintaining full backward compatibility with pnpm 11 workflows, including commands, flags, settings, and lockfile formats.

Internal benchmarks indicate substantial performance gains. A clean install of a file-heavy fixture dropped from 8.2 seconds to 5 seconds. In scenarios involving existing caches and lockfiles, installation times fell from 472 milliseconds to 15 milliseconds. Independent testing by Socket reported that Vercel’s Turborepo workspace saw median installation time reductions ranging from 64.4% to 90.5%.

The new version is approximately 65.9% Rust and 33.5% TypeScript. While the native Corepack artifact is slightly larger—resulting in an 11.1% slower first uncached startup—cached startup performance improved by 74.7%. The update also introduces project-aware global binaries and a new Rust-based registry server called pnpr to further enhance performance.