Installation

Add Cipher to your project


npm install @privacy-protocol/cipher-contracts @fhevm/solidity @openzeppelin/contracts

This installs:

@privacy-protocol/cipher-contracts — the Cipher Solidity sources (the adapters)
@fhevm/solidity — Zama’s FHE library (peer dependency)
@openzeppelin/contracts — standard contract primitives (peer dependency)

Hardhat configuration

Cipher contracts target Solidity 0.8.27 on the Cancun EVM, and FHE needs the fhEVM plugin:


// hardhat.config.ts
import { HardhatUserConfig } from "hardhat/config";
import "@nomicfoundation/hardhat-toolbox";
import "@fhevm/hardhat-plugin";
import "dotenv/config";
 
const config: HardhatUserConfig = {
  solidity: {
    version: "0.8.27",
    settings: {
      optimizer: { enabled: true, runs: 10 },
      evmVersion: "cancun",
    },
  },
  networks: {
    sepolia: {
      url: process.env.SEPOLIA_RPC_URL ?? "",
      accounts: process.env.PRIVATE_KEY ? [process.env.PRIVATE_KEY] : [],
    },
  },
};
 
export default config;


npm install --save-dev @fhevm/hardhat-plugin @nomicfoundation/hardhat-toolbox dotenv

Some adapters include a large on-chain verifier; the low optimizer runs (10) keeps deployment bytecode within limits. If you only deploy your own contracts (and reuse a shared verifier), you can raise it.

Off-chain dependencies

If your app generates proofs or encrypts inputs, add the client stack (see the adapter’s docs for pinned versions):


npm install @noir-lang/noir_js @aztec/bb.js @zama-fhe/relayer-sdk

Verify the install

Cipher ships Solidity sources under @privacy-protocol/cipher-contracts/src/.... Import a symbol from the adapter you plan to use and compile. For the Private DAO Adapter:


// contracts/TestImport.sol
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.27;
 
import {IPrivateDaoAdapter} from
    "@privacy-protocol/cipher-contracts/src/DaoToolkit/interface/IPrivateDaoAdapter.sol";
 
contract TestImport {
    IPrivateDaoAdapter public adapter;
    constructor(address _adapter) {
        adapter = IPrivateDaoAdapter(_adapter);
    }
}


npx hardhat compile

If it compiles, you’re ready. Delete TestImport.sol and head to Adapters.

Next steps

Adapters — choose an adapter and start integrating