# Starknet ERC-20 Testnet Deployment Tutorial



By [Dev_Leo](https://paragraph.com/@iwantairdrop) · 2022-08-29

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Starknet is a Layer2 network over Ethereum for unlimited scale for its computation.Contracts are written in Cairo, a programming language for writing provable programs.

In this tutorial, we write a standard ERC-20 contacts and deploy to goerli Starknet.Compared to ERC-20 written with solidity, our implement are also based on OpenZeppelin's Cairo Library.

### Setting up the environment

We create a python virtual environment.And then install packages and dependencies inside the environment.

    python -m venv ~/cairo_venv
    source ~/cairo_venv/bin/activate
    

You should see(cairo\_venv) in the command line like the following screenshot.

![cairo_venv](https://storage.googleapis.com/papyrus_images/ae416ae483f2f41e53636b5b4cd0b2dc7303b39bcdec4a3b53bc17fb4b85c96a.png)

cairo\_venv

Install gmp.

On Ubuntu

    sudo apt install -y libgmp3-dev
    

On mac, you can use brew:

Install the cairo-lang python packages using:

    pip install cairo-lang
    

For this project, like we mentioned above, we will install OpenZapplin Contracts Library.And Nile, a development environment for Cairo.

    pip install cairo-nile openzeppelin-cairo-contracts
    

Finally, run nil init to initial cairo environment which includes a local network, a testing framework, and some sample codes.

    mkdir my-proj
    cd my-proj
    nile init
    

### Import the library

we'll create an ERC20 token contract base on OpenZeppline's Library with few lines. Create a MyToken.cairo file:

    %lang starknet
    from openzeppelin.token.erc20.ERC20 import constructor
    

This is a full functional ERC20 token implement with implemented Library.All basic logic are set in the library.

### Deploy to the testnet

Firstly we compile the code.

    nile compile
    

and then we can deploy to the testnet

    nile deploy MyToken <name> <symbol> <decimals> <initial_supply> <recipient> --alias my_token
    

Alternatively, some params should be passed as felt type, so we use nile's python api instead.

    # scripts/deploy.py
    def run(nre):
        print("Compiling contract…")
        nre.compile(["contracts/MyToken.cairo"]) # we compile our contract first
        print("Deploying contract…")
        name = str(str_to_felt("MyToken"))
        symbol = str(str_to_felt("MTK"))
        decimals = "18"
        recipient = "0x057e792bbff407d7a128e61a722721bcc5ca8cf0488d4fe2d72fadd577e1c194"
        params = [name, symbol, decimals, "100", "0", recipient]
        address, abi = nre.deploy("MyToken", params, alias="my_token")
        print(f"ABI: {abi},\nContract address: {address}")
    # Auxiliary functions
    def str_to_felt(text):
        b_text = bytes(text, "ascii")
        return int.from_bytes(b_text, "big")
    def uint(a):
        return(a, 0)
    

Execute it with nile run:

    nile run scripts/deploy.py
    

### Interacting with the token

We can call functions:

    nile call my_token totalSupply
    
    100 0
    

and we can check the contract at [voyager's testnet explorer](https://goerli.voyager.online/).

![](https://storage.googleapis.com/papyrus_images/57457157e6a7d4272d737e89db49927144c715d96e456ded3e7b20824eea8fec.png)

### Conclusion

As above, we had written few lines and deployed contracts to testnet. With the help of OpenZeppline’s library, developing a ERC20 contract is quite easy for beginners.Hope this tutorial can open the door for you to the Starknet’s zk world!

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*Originally published on [Dev_Leo](https://paragraph.com/@iwantairdrop/starknet-erc-20-testnet-deployment-tutorial)*