protons

Protons is a high-performance Protocol Buffers v3 transpiler that converts .proto files into TypeScript. Current stable version is 8.1.1 (March 2026), with active development under the IPFS project. It differs from protobuf.js by supporting only proto3 semantics, using BigInts for 64-bit types (not Longs), representing optional unset fields as undefined, and deserializing map fields as ES6 Maps. Protons also allows limiting repeated/map element sizes for security and supports streaming decode since v8.0.0. Ships TypeScript types and requires both protons (dev) and protons-runtime (runtime) packages.