Installation

Install and configure @cofhe/sdk for your project

Prerequisites

• Node.js 18+
• TypeScript 5+
• Viem 2+

Install packages

npm

npm install @cofhe/sdk@^0.5.1 @fhenixprotocol/cofhe-contracts@^0.1.3

pnpm add @cofhe/sdk@^0.5.1 @fhenixprotocol/cofhe-contracts@^0.1.3

yarn add @cofhe/sdk@^0.5.1 @fhenixprotocol/cofhe-contracts@^0.1.3

Package	Version	Purpose
@cofhe/sdk	^0.5.1	Client-side encryption, decryption, and permit management
@fhenixprotocol/cofhe-contracts	^0.1.3	FHE.sol — the Solidity library imported by your contracts

@fhenixprotocol/cofhe-contracts@0.1.3 requires @cofhe/sdk version >= 0.5.1.

For Hardhat projects

If you are using Hardhat for development and testing, also install the plugin:

npm

npm install @cofhe/hardhat-plugin@^0.5.1 @cofhe/sdk@^0.5.1 @fhenixprotocol/cofhe-contracts@^0.1.3

pnpm add @cofhe/hardhat-plugin@^0.5.1 @cofhe/sdk@^0.5.1 @fhenixprotocol/cofhe-contracts@^0.1.3

yarn add @cofhe/hardhat-plugin@^0.5.1 @cofhe/sdk@^0.5.1 @fhenixprotocol/cofhe-contracts@^0.1.3

Package	Version	Purpose
@cofhe/hardhat-plugin	^0.5.1	Extends Hardhat with hre.cofhe, deploys mock contracts automatically
@cofhe/sdk	^0.5.1	Client-side encryption, decryption, and permit management
@fhenixprotocol/cofhe-contracts	^0.1.3	FHE.sol — the Solidity library imported by your contracts

See the Hardhat Plugin Getting Started guide for configuration details.

For Foundry projects

If you are using Foundry for development and testing, install the Foundry plugin and its peer packages as dev dependencies:

npm

npm install -D @cofhe/foundry-plugin@^0.5.1 @cofhe/mock-contracts@^0.5.1 @fhenixprotocol/cofhe-contracts@^0.1.3 @openzeppelin/contracts
forge install foundry-rs/forge-std

pnpm add -D @cofhe/foundry-plugin@^0.5.1 @cofhe/mock-contracts@^0.5.1 @fhenixprotocol/cofhe-contracts@^0.1.3 @openzeppelin/contracts
forge install foundry-rs/forge-std

yarn add -D @cofhe/foundry-plugin@^0.5.1 @cofhe/mock-contracts@^0.5.1 @fhenixprotocol/cofhe-contracts@^0.1.3 @openzeppelin/contracts
forge install foundry-rs/forge-std

Package	Version	Purpose
@cofhe/foundry-plugin	^0.5.1	CofheTest and CofheClient — Solidity test base and per-user SDK shim
@cofhe/mock-contracts	^0.5.1	Mock CoFHE contracts used by the Foundry plugin
@fhenixprotocol/cofhe-contracts	^0.1.3	FHE.sol — the Solidity library imported by your contracts

The Foundry plugin uses Solidity-only abstractions — no @cofhe/sdk (JS) needed for tests.

See the Foundry Plugin Getting Started guide for foundry.toml and remappings.txt setup.

Runtime entrypoints

Import from the entrypoint that matches your runtime:

// Browser apps (React, Next.js, etc.)
import { createCofheConfig, createCofheClient } from '@cofhe/sdk/web';

// Node.js scripts, backends, Hardhat tests
import { createCofheConfig, createCofheClient } from '@cofhe/sdk/node';

// Shared types (works in any runtime)
import { Encryptable, FheTypes } from '@cofhe/sdk';

Next steps

• Quick Start — write your first FHE contract and test
• Client Setup — configure and connect the SDK client