Introduction

This section provides an overview of the Noir Stylus Verifier.

What this project is

Noir Stylus Verifier (NSV) helps you generate and deploy Stylus-compatible verifier contracts for Noir circuits on Arbitrum Stylus. It automates:

  • Generating a verifier contract from a Noir circuit.
  • Checking Stylus compatibility and deployment cost.
  • Deploying the verifier to a Stylus chain.
  • Creating and verifying proofs for testing (locally or onchain).

Prerequisites

If you don't have them install them, otherwise ensure specified versions

  • Noir nargo 1.0.0-beta.6
  • Barretenberg bb 0.86.0
  • Rust
  • Cargo Stylus
  • Linux/MacOs. Currently Windows is not supported by Noir.

Install Noir and Barretenberg specific versions::

# Install Noir (nargo)
curl -L https://raw.githubusercontent.com/noir-lang/noirup/refs/heads/main/install | bash
noirup -v 1.0.0-beta.6

# Install Barretenberg (bb)
curl -L https://raw.githubusercontent.com/AztecProtocol/aztec-packages/refs/heads/master/barretenberg/bbup/install | bash
bbup -v 0.86.0

Install Rust with rustup as per indicated here

Install Cargo Stylus and WebAssembly target:

cargo install cargo-stylus
rustup target add wasm32-unknown-unknown

Install the NSV CLI

We strongly recommend going to the latest GitHub Release and following instructions from there. Then do run nsv --help to verify installation and see available commands.

Quick start: from a fresh Noir project to a deployed Stylus verifier

  1. Create a Noir project

With nsv

nsv new hello_world
cd hello_world

Or with nargo

nargo new hello_world
cd hello_world
  1. Generate the Stylus verifier contract

From the circuit’s root folder:

nsv generate

What happens:

  • Compiles the circuit to bytecode (unless you pass --bytecode-path)
  • Writes the verification key with bb write_vk (unless you pass --vk-path)
  • Generates a Stylus verifier project at contracts/

Notice the generated verifier encodes your vk in a call to a global verifier. The cli already provides some default addresses for these but feel free to do your own deployment as per instructed here and specify that while deploying.

  1. Check Stylus compatibility and estimated cost of the generated verifier. (It may take some time the first run as it downloads crates and compiles the contracts package)
nsv check --rpc-url https://sepolia-rollup.arbitrum.io/rpc
  1. Deploy the verifier to Stylus
nsv deploy --rpc-url <RPC_URL> --private-key <HEX_PRIVATE_KEY>

Notes:

  • If you omit --verifier-address, NSV will select a default for the chain when available (this the global stylus verifier).
  • Add --zk to deploy the zk-flavored verifier variant when needed (in this case helps preselecting the global verifier address, if --verifier-address is passed you have to consider this).
  1. Generate a proof for testing
nsv prove

By default this will:

  • Execute the circuit with Noir to produce a witness (unless --witness-path and --bytecode-path are provided)
  • Produce target/proof and target/public_inputs
  • Remember to add --zk if you're using the zk flavoured verifier.
  1. Verify the proof
  • Locally (Barretenberg):
nsv verify

By default this will:

  • Take proof from target/proof, public inputs from target/public_inputs and vk from contracts/assets/vk

  • Onchain (calls the deployed verifier):

nsv verify \
  --verifier-address <DEPLOYED_VERIFIER_ADDRESS> \
  --rpc-url <RPC_URL>

Also, remember to set the --zk flag if you're using a zk flavoured verifier. Check nsv verify --help for more options.

Troubleshooting

  • Missing dependencies: the CLI validates required versions of nargo, bb, and cargo stylus. Reinstall per the steps above if a version mismatch is reported.
  • Bytecode/VK paths: when supplying --bytecode-path or --vk-path, ensure files exist relative to the project root.
  • Package detection: run from your Noir project root or pass -p <package_name>.

Learn more