OGBank

Private lending protocol powered by ZK proofs on Avalanche. Users supply ZEC collateral, borrow USDC via Aave V3, and prove repayment with zero-knowledge proofs to withdraw collateral — all without linking deposit and withdrawal addresses.

Architecture

packages/
  circuits/     Noir ZK circuit (borrow + auth modes)
  contracts/    Solidity contracts (OGBankContract, Verifier, mocks)
apps/
  landing/      Marketing landing page
  webapp/       Protocol dashboard (connect wallet, view balances)

Prerequisites

Tool	Version	Install
Node.js	>= 18	https://nodejs.org
Foundry (forge, anvil)	latest	curl -L https://foundry.paradigm.xyz | bash && foundryup
Nargo (Noir)	1.0.0-beta.19	https://noir-lang.org/docs/getting_started
bb (Barretenberg)	latest	Installed with Nargo
jq	any	brew install jq

Setup

# Install all workspace dependencies
npm install

# Install Foundry dependencies
cd packages/contracts && forge install && cd ../..

Local Development (anvil)

1. Start anvil

The HonkVerifier contract exceeds the default EVM contract size limit, so anvil must be started with --code-size-limit:

npm run anvil:start

This runs anvil --code-size-limit 50000 on http://127.0.0.1:8545.

2. Deploy contracts

In a separate terminal:

npm run contracts:deploy:anvil

This does three things:

1. Deploys HonkVerifier, MockERC20 (ZEC + USDC), MockAavePool, and OGBankContract to anvil
2. Mints 10,000 ZEC and 10,000 USDC to the default anvil account (0xf39F...2266)
3. Writes all contract addresses to apps/webapp/.env

3. Start the webapp

npm run webapp:dev

Open http://localhost:5173, connect with MetaMask (import anvil's first private key: 0xac0974bec39a17e36ba4a6b4d238ff944bacb478cbed5efcae784d7bf4f2ff80), and you should see your native ETH balance plus 10,000 ZEC (collateral) and 10,000 USDC (borrow).

ZK Circuits

# Compile the Noir circuit
npm run circuits:build

# Run circuit tests
npm run circuits:test

# Regenerate the Solidity verifier from the compiled circuit
npm run circuits:verifier

After regenerating the verifier, rebuild contracts with npm run contracts:build.

Smart Contracts

# Build
npm run contracts:build

# Run all tests
npm run contracts:test

# Unit tests only
npm run contracts:test:unit

# Integration tests only
npm run contracts:test:integration

# Coverage
npm run contracts:coverage

Testnet Deployment

Avalanche Fuji

Create packages/contracts/.env:

FUJI_RPC=https://api.avax-test.network/ext/bc/C/rpc
FUJI_DEPLOYER_NAME=my-fuji-deployer

Then:

cd packages/contracts
npm run deploy:fuji

Sepolia

Create packages/contracts/.env:

SEPOLIA_RPC=https://eth-sepolia.g.alchemy.com/v2/YOUR_KEY
SEPOLIA_DEPLOYER_NAME=my-sepolia-deployer

Then:

cd packages/contracts
npm run deploy:sepolia

All Root Scripts

Script	Description
npm run anvil:start	Start local anvil node
npm run contracts:deploy:anvil	Deploy to anvil + write webapp .env
npm run contracts:build	Compile Solidity contracts
npm run contracts:test	Run all Forge tests
npm run contracts:test:unit	Run unit tests
npm run contracts:test:integration	Run integration tests
npm run contracts:coverage	Generate coverage report
npm run circuits:build	Compile Noir circuit
npm run circuits:test	Run circuit tests
npm run circuits:verifier	Regenerate Solidity verifier
npm run webapp:dev	Start webapp dev server
npm run webapp:build	Build webapp for production
npm run landing:dev	Start landing page dev server
npm run landing:build	Build landing page