Welcome
o1js is a TypeScript SDK for writing zero knowledge proofs. o1Labs is committed to building a better internet powered by programmable cryptography, and o1js the tool of choice for developers looking to supercharge their applications with ZK.
o1js is a complete toolkit that runs in node or on the browser, and it can be integrated into any existing TypeScript codebase. It is also compatible with the Mina blockchain, and can be used to write ZkApps for Mina, Protokit, and Zeko.
Installation
Just like any Typescript project, o1js can be installed via your preferred package manager
npm i o1js
Is it Really "Just Javascript"?
No! The SDK itself is written in TypeScript, but the advanced cryptography being used by o1js is actually accessed via a bindings layer to rust and ocaml code. o1js can produce constraint systems, often called "circuits", which are a system of gates and wires that represent a mathematical function. The execution strategy of o1js is to dry-run the execution in JavaScript, and if there are no issues, call the constraint system for real.
TODO: Would be nice to have a graphic that visualizes the execution steps of provable code!
Browser Compatibility
o1js balances browser support and feature richness. Most modern browsers, including many mobile browsers
are supported. We use WebAssembly and SharedArrayBuffer to improve prover performance on the browser,
which does impact compatibility with older browsers. See below for a full list of supported browsers.
Check supported browsers on Browserlist
SharedArrayBuffer requires Cross-Origin-Opener-Policy and Cross-Origin-Embedder-Policy headers to be set.
Cross-Origin-Opener-Policy: same-origin
Cross-Origin-Embedder-Policy: require-corp