Quick Start: Hardhat

import { HardhatUserConfig } from 'hardhat/config';
import '@nomicfoundation/hardhat-toolbox';
import '@cofhe/hardhat-plugin';

const config: HardhatUserConfig = {
  solidity: {
    version: '0.8.28',
    settings: {
      evmVersion: 'cancun',
    },
  },
};

export default config;

// SPDX-License-Identifier: UNLICENSED
pragma solidity ^0.8.28;

import '@fhenixprotocol/cofhe-contracts/FHE.sol';

contract MyContract {
  euint32 public storedValue;

  function setValue(externalEuint32 inValue, bytes calldata inputProof) external {
    storedValue = FHE.asEuint32(inValue, inputProof);
    FHE.allowThis(storedValue);
    FHE.allowSender(storedValue);
  }
}

import hre from 'hardhat';
import { CofheClient, Encryptable, FheTypes } from '@cofhe/sdk';
import { HardhatEthersSigner } from '@nomicfoundation/hardhat-ethers/signers';
import { expect } from 'chai';

describe('MyContract', () => {
  let cofheClient: CofheClient;
  let signer: HardhatEthersSigner;

  before(async () => {
    [signer] = await hre.ethers.getSigners();
    cofheClient = await hre.cofhe.createClientWithBatteries(signer);
  });

  it('stores and decrypts an encrypted value', async () => {
    const Factory = await hre.ethers.getContractFactory('MyContract');
    const contract = await Factory.deploy();

    // 1. Encrypt the input, bound to the contract that will consume it
    const [valueHash, signature] = await cofheClient
      .encryptInputs([Encryptable.uint32(42n)])
      .setConsumingContract(await contract.getAddress())
      .execute();

    // 2. Send to contract
    await (await contract.setValue(valueHash, signature)).wait();

    // 3. Read the stored handle and decrypt
    const ctHash = await contract.storedValue();
    const decrypted = await cofheClient
      .decryptForView(ctHash, FheTypes.Uint32)
      .execute();

    expect(decrypted).to.equal(42n);
  });
});