Privacy Protocol

Privacy Protocol is a relayer-first privacy middleware for EVM dApps built on Arbitrum. It lets developers easily build confidential dApps by adding an incognito execution path to new and existing dApps without rewriting their core contracts or building custom ZK systems from scratch.

What It Includes

• Privacy pool contracts for note-based private execution.

• Noir circuits for proof generation and verification.

• Browser-ready TypeScript SDK package (privacy-protocol) with privacy-protocol/core and privacy-protocol/hooks.

• Rust relayer service for batching and on-chain submission.

• Next.js demo frontend (DAO voting + DeFi swap) showing public vs private flow.

Tech Stack

Layer	Stack
Contracts	Solidity, Foundry
Circuits	Noir, Poseidon dependency
SDK	TypeScript, Ethers, @noir-lang/noir_js, @aztec/bb.js, tsup
Relayer	Rust, Axum, Tokio, Ethers-rs, Serde, Tracing
Frontend	Next.js, TypeScript, Wagmi, Viem, ConnectKit, Tailwind CSS

Deployments (Arbitrum Sepolia)

Chain ID: 421614

Contract	Address
PrivacyProtocolPool	0xA0806cf43f5E9A2C42c8291676EE814b39A6413e
DemoDao	0x0B25AbD0136f6Ed5C220604Ec27026522515194f
DemoDefi	0xA8DCc58D83Cae0FfF1076832Ef7E5a5D9B96D9d7
HonkVerifier	0x4eE4661b8Ad32Ca08fED028Fe1490303f6D61BDA

Source: contracts/src/Constants.sol

Public Infra Endpoints

• Relayer endpoint: https://privacy-protocol-relayer.onrender.com/relay

• Explorer: https://sepolia.arbiscan.io

• Docs site: https://privacy-protocol-hi8x.vercel.app/docs

Frontend Setup (Only)

This section is only for running the demo frontend locally, after cloning the repo.

1. Install dependencies

cd frontend
npm install --legacy-peer-deps

2. Configure environment

Create frontend/.env.local:

NEXT_PUBLIC_WALLET_ID=<your_walletconnect_project_id>
NEXT_PUBLIC_ALCHEMY_ID=<your_alchemy_api_key>

Optional overrides:

NEXT_PUBLIC_DOCS_URL=https://privacy-protocol-hi8x.vercel.app/docs
NEXT_PUBLIC_PRIVACY_PROTOCOL_RELAYER_URL=https://privacy-protocol-relayer.onrender.com
NEXT_PUBLIC_PRIVACY_PROTOCOL_RELAYER_ENDPOINT=/relay

3. Run the app

npm run dev

Open http://localhost:3000.

4. Production build check

npm run build
npm start