Deploying Your First Token

This guide walks through creating and deploying a basic ERC20 token on CointMU using OpenZeppelin 4.9.x and the cmu CLI.

Prerequisites

Requirement	Details
Running CointMU node	Geth `1.10.26` running on Chain ID `1912`.
Nginx proxy	Available at `http://10.64.24.101:8585`.
Funded deployer account	Its private key, and enough CMU for gas. `cmu` signs locally.
Active miner	At least one miner running so transactions are included in blocks.
CointMU project	A project scaffolded with `cmu create` or an existing compatible structure.

1. Scaffold the Project

If you don't have an existing project, create one using the erc20 template:

bash

cmu create my-token --template erc20 --language typescript
cd my-token

This generates the full project structure including contracts/, deploy/, and artifacts/.

The erc20 template already contains contracts/StandardERC20.sol and deploy/01_standarderc20.ts. Delete both if you only want the token below; otherwise cmu deploy runs that script too.

2. Install Dependencies

bash

npm install
npm install @openzeppelin/contracts@4.9.6

WARNING

Do not install @openzeppelin/contracts@5.x. Version 5 requires solc 0.8.20+ which emits the PUSH0 opcode, causing an invalid opcode error on Geth 1.10.26. Always use 4.9.x.

See Supported Libraries for the full compatibility reference.

3. Write the Token Contract

Create the token contract in contracts/CMUS.sol:

solidity

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;

import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
import "@openzeppelin/contracts/access/Ownable.sol";

contract CMUS is ERC20, Ownable {
    constructor() ERC20("CointMU Token", "CMUS") {
        _mint(msg.sender, 1_000_000 * 10 ** decimals());
    }
}

INFO

The pragma matches the ^0.8.20 used by every built-in template. Compatibility with Geth 1.10.26 comes from the EVM target rather than the pragma: cmu compile sets evmVersion: "paris", which suppresses the PUSH0 opcode that the compiler would otherwise emit under its default shanghai target. See Supported Libraries.

4. Add the Deployment Script

Create deploy/01_deploy_cmus.ts and point it at the Nginx proxy URL:

typescript

import { ethers } from "ethers";
import fs from "node:fs";
import path from "node:path";

async function main() {
  const rpcUrl = process.env.CMU_RPC_URL ?? "http://10.64.24.101:8585";
  const provider = new ethers.JsonRpcProvider(rpcUrl, 1912);

  const wallet = new ethers.Wallet(process.env.PRIVATE_KEY as string, provider);

  const artifactPath = path.resolve("artifacts", "CMUS.json");
  const artifact = JSON.parse(fs.readFileSync(artifactPath, "utf8"));

  const factory = new ethers.ContractFactory(
    artifact.abi,
    artifact.evm.bytecode.object,
    wallet,
  );

  console.log("Deploying CMUS token...");
  const token = await factory.deploy();
  await token.waitForDeployment();

  console.log("CMUS deployed to:", await token.getAddress());
}

main().catch((error) => {
  console.error(error);
  process.exitCode = 1;
});

TIP

The script reads CMU_RPC_URL and PRIVATE_KEY from environment variables. These are injected automatically by cmu deploy — no manual .env configuration is needed when running through the CLI.

5. Point the Project at the Server

cmu deploy and cmu mine choose their network in different places, so both need to point at the server. See Which Network a Command Uses.

In cmu.config.ts, give the scaffolded mainnet entry the server's URL — it ships with an empty url — and make it the default:

typescript

  defaultNetwork: "mainnet",
  networks: {
    // ...
    mainnet: {
      url: "http://10.64.24.101:8585",
      chainId: 1912,
      symbol: "CMU",
    },
  },

symbol: "CMU" is already there in projects created by cmu create 1.7.0 or later; in an older project, add it so cmu explorer labels balances CMU instead of ETH.

Then save the deployer key as a wallet, activate it in the project, and point the session at the same server:

bash

cmu wallet save deployer
cmu wallet use deployer
cmu network save http://10.64.24.101:8585 --name cointmu --symbol CMU
cmu network use cointmu

cmu wallet save prompts for the private key and a new password; cmu wallet use makes it the key cmu deploy signs with. See cmu wallet.

--symbol CMU makes cmu wallet balance, cmu wallet transfer and cmu mine show amounts on this network in CMU instead of ETH. Since 1.7.0; see Coin Symbol.

6. Start the Miner

Before deploying, ensure the network is actively producing blocks. Open the Geth console and start the miner:

bash

geth attach ./data/geth.ipc

miner.start(1);

Or use the cmu CLI, which mines to the session wallet on the session's network:

bash

cmu mine status
cmu mine start

cmu mine start moves the node's mining rewards to your wallet for everyone mining on it. Check cmu mine status first on a shared server. See cmu mine.

If no miner is running, the deployment transaction remains pending and the contract will never be mined into a block.

7. Compile

bash

cmu compile

cmu compile resolves OpenZeppelin imports from node_modules automatically. Compiled artifacts are written to artifacts/CMUS.json.

8. Deploy

bash

cmu deploy

cmu deploy triggers a recompile, resolves the network from defaultNetwork in cmu.config.ts, prompts once for the session password, and executes deploy/01_deploy_cmus.ts sequentially.

Expected output:

bash

warning: the following project files will be executed as code:
      cmu.config.ts       ->  /home/you/my-token/cmu.config.ts
      01_deploy_cmus.ts   ->  /home/you/my-token/deploy/01_deploy_cmus.ts

? Execute these files? Yes

Compiling contracts...
Compiling 1 Solidity file(s)...
Compiled CMUS
? Session password for 0x...: *************

--- Deploy configuration ---
Network      : mainnet
RPC endpoint : http://10.64.24.101:8585
Chain ID     : 1912
Deployer     : 0x...
----------------------------

Found 1 deploy script(s); running them in order...

========================================
Running 01_deploy_cmus.ts
========================================

Deploying CMUS token...
CMUS deployed to: 0x...

All deploy scripts completed.

--- Deployed on 'mainnet' (chain 1912) ---
CMUS  0x...  block <n>  -> deployments/mainnet/CMUS.json
----------------------------------------

The last block is the deployment record: the address is saved in deployments/mainnet/CMUS.json, which is meant to be committed.

INFO

The first prompt is the trust gate: deploy scripts run with your decrypted PRIVATE_KEY in their environment, so the CLI lists every project file it is about to execute and asks before running any of it. Pass -y, --yes in a pipeline. See the trust model.

9. Verify the Deployment

After deployment, confirm the contract is live by checking the deployed address in the Explorer or querying it directly:

typescript

const token = new ethers.Contract(
  "0x<deployed_address>",
  artifact.abi,
  provider,
);

console.log("Name:", await token.name());
console.log("Symbol:", await token.symbol());
console.log("Total Supply:", ethers.formatEther(await token.totalSupply()));

Or confirm it from the CLI. cmu explorer --contract shows the code at the address and checks it against the record, and getDeployed in cmu console loads the recorded contract:

bash

cmu explorer --contract 0x<deployed_address>
cmu console

bash

cmu> const token = await getDeployed("CMUS")
cmu> await token.symbol()
'CMUS'

Deploying Your First Token ​

Prerequisites ​

1. Scaffold the Project ​

2. Install Dependencies ​

3. Write the Token Contract ​

4. Add the Deployment Script ​

5. Point the Project at the Server ​

6. Start the Miner ​

7. Compile ​

8. Deploy ​

9. Verify the Deployment ​

Deploying Your First Token

Prerequisites

1. Scaffold the Project

2. Install Dependencies

3. Write the Token Contract

4. Add the Deployment Script

5. Point the Project at the Server

6. Start the Miner

7. Compile

8. Deploy

9. Verify the Deployment