x402 Cross Chain Confidential Payment

Overview

• This is the x402 Cross Chain Confidential Payment built on Aztec Network, which the smart contract is written in Noir.
  • Also, this project is built on the Aztec EVM Bridge (powered by Substance Labs) to enable the cross chain confidential payment.

Technical Stack

• Smart Contract: Noir

  • nargo/noirc: v1.0.0-beta.16

• Blockchain: Aztec Network (Ethereum L2 Rollup)

  • aztec package: v3.0.0-devnet.2

Remarks

• This repo is originally forked from the aztec-workshop repo.

Setup

1. Install Aztec by following the instructions from their documentation.
2. Install the dependencies by running: yarn install
3. Ensure you have Docker installed and running (required for Aztec sandbox)

SC Compile & Build

The complete build pipeline includes cleaning, compiling Noir contracts, and generating TypeScript artifacts:

yarn ccc

This runs:

• yarn clean - Removes all build artifacts
• yarn compile - Compiles Noir contracts using aztec-nargo
• yarn codegen - Generates TypeScript bindings from compiled contracts

NOTE:

• Currently, the partial_att_verifier is moved to the nr/pending directory - due to compile errors-caused by the aztec-packages version mismatch (v3.0.0-devnet.2 and v3.0.0-devnet.5).

Smart Contract Test

Noir tests only

Test your contract logic directly:

yarn test:nr

e2e Test

TypeScript integration tests only

Test contract interactions through TypeScript:

yarn test:js

Resources

• Aztec Documentation
• Noir Language Documentation
• Aztec Sandbox Quickstart
• Aztec Contracts Guide