@aztec/noir-contracts

Noir contracts

This package contains the source code and the Aztec ABIs for the example contracts used in tests.

Setup

Installing Noir

• Install noirup

  curl -L https://raw.githubusercontent.com/noir-lang/noirup/main/install | bash
  

• Nix is already globally installed but path to this installation needs to be added in $HOME/.zshenv so correct configuration can be found by VSCode, do so with:

  echo -e '\n# Nix path set globally\nexport PATH="$HOME/.nix-profile/bin:/nix/var/nix/profiles/default/bin:$PATH"' >> $HOME/.zshenv
  

• Enable nix flake command in ~/.config/nix/nix.conf with commands:

  mkdir -p $HOME/.config/nix && echo -e '\nexperimental-features = nix-command\nextra-experimental-features = flakes' >> $HOME/.config/nix/nix.conf
  

• Install direnv into your Nix profile by running:

  nix profile install nixpkgs#direnv
  

• Add direnv to your shell following their guide

  echo -e '\n# Adds direnv initialization\neval "$(direnv hook zsh)"' >> $HOME/.zshenv
  

• VSCode needs to be resterted so direnv plugin can notice env changes with:

  kill -9 ps aux | grep $(whoami)/.vscode-server | awk '{print $2}'
  

• Restart shell

• Clone noir repo:

  git clone https://github.com/noir-lang/noir.git
  

• Checkout aztec3 branch

  cd noir
  git checkout aztec3
  

• Enable direnv

  direnv allow
  

• Restart shell

• Go to the noir dir and install Noir:

  cd noir
  noirup -p ./
  

Building the contracts

• In the aztec-packages repository, go to the directory yarn-project/noir-contracts

• Use the noir:build:all script to compile the contracts you want and prepare the ABI for consumption

  yarn noir:build:all
  

  Alternatively you can run yarn noir:build CONTRACT1 CONTRACT2... to build a subset of contracts:

  yarn noir:build zk_token public_token
  

  To view compilation output, including errors, run with the VERBOSE=1 flag:

  VERBOSE=1 yarn noir:build zk_token public_token
  

Creating a new contract package

1. Go to src/contracts folder.

2. Create a new package whose name has to end with _contract. E.g.:

   nargo new example_contract
   

3. Add the aztec dependency to nargo.toml:

   [package]
   authors = [""]
   compiler_version = "0.7.1"
   
   [dependencies]
   aztec = { path = "../../libs/noir-aztec" }
   

4. Replace the content of the generated example_contract/src/main.nr file with your contract code.

5. Go to noir-contracts root folder and run yarn noir:build example to compile the contract.

6. Export the abi in src/examples/index.ts to be able to use the contract in the rest of the project:

   import ExampleContractJson from './example_contract.json' assert { type: 'json' };
   export const ExampleContractAbi = ExampleContractJson as ContractAbi;
   

7. ???

8. Profit.