Build a web application

Using a template

fhevmjs is working out of the box and we recommend you to use it. We also provide three GitHub templates to start your project with everything set.

React + TypeScript

You can use this template to start an application with fhevmjs, using Vite + React + TypeScript.

VueJS + TypeScript

You can also use this template to start an application with fhevmjs, using Vite + Vue + TypeScript.

NextJS + Typescript

You can also use this template to start an application with fhevmjs, using Next + TypeScript.

Using directly the library

First, you need to install the library.

# Using npm
npm install fhevmjs

# Using Yarn
yarn add fhevmjs

# Using pnpm
pnpm add fhevmjs

fhevmjs uses ESM format. You need to set the type to "module" in your package.json. If your node project use "type": "commonjs" or no type, you can force the loading of the web version by using import { createInstance } from 'fhevmjs/web';

To use the library in your project, you need to load the WASM of TFHE first with initFhevm.

import { initFhevm } from "fhevmjs";

const init = async () => {
  await initFhevm(); // Load needed WASM
};

Once the WASM is loaded, you can now create an instance. An instance receives an object containing:

• chainId (optional): the chainId of the network

• network (optional): the Eip1193 object provided by window.ethereum (used to fetch the public key and/or chain id)

• networkUrl (optional): the URL of the network (used to fetch the public key and/or chain id)

• publicKey (optional): if the public key has been fetched separately (cache), you can provide it

• gatewayUrl (optional): the URL of the gateway to retrieve a reencryption

• coprocessorUrl (optional): the URL of the coprocessor

import { initFhevm, createInstance } from "fhevmjs";

const init = async () => {
  await initFhevm(); // Load TFHE
  return createInstance({
    network: window.ethereum,
    gatewayUrl: "https://gateway.zama.ai/",
  });
};

init().then((instance) => {
  console.log(instance);
});

You can now use your instance to encrypt parameters or do a reencryption.