Token template walkthrough

Follow the token template file by file, from the contract to the web app, so you know what to change and what to leave alone.

Ready. This template is published in uzolabs/templates and has been deployed and verified on testnet. It’s a learning template and hasn’t been audited. Use test funds only.

Project layout

contracts/UzoToken.sol        the token
test/UzoToken.t.sol           Solidity tests, run by Foundry and by Hardhat
script/Deploy.s.sol           Foundry deploy script
ignition/modules/UzoToken.ts  Hardhat Ignition deploy module
scripts/deploy.ts             runs either deployer, then saves the result
scripts/verify.ts             runs either verifier with the saved arguments
scripts/transfer.ts           sends tokens from the command line
scripts/lib/                  network selection, mainnet guard, Ignition fee hook, helpers
frontend/                     Vite + React + wagmi web app
deployments/<chainId>.json    written by deploy

The contract

contracts/UzoToken.sol combines three OpenZeppelin contracts:

Parent	What it adds
`ERC20`	Balances, transfers and allowances
`ERC20Permit`	Approvals by signature (EIP-2612), so a user can approve without a separate transaction
`Ownable`	One owner, the only account that can call `mint`

The constructor takes (name, symbol, initialSupply, owner) and mints the initial supply to the owner. The deploy scripts pass the deployer as the owner.

Tests

test/UzoToken.t.sol holds 18 Solidity tests. forge test and hardhat test solidity both run the same file, so you write each test once.

Terminal

npm test
npm run test:hardhat

Two toolchains, one project

foundry.toml and hardhat.config.ts both point at contracts/ and test/, and both compile with Solidity 0.8.28 for the cancun EVM. Foundry finds imports through remappings.txt. Hardhat finds them in node_modules. OpenZeppelin and forge-std come from npm, so there are no git submodules to update.

Deploying

scripts/deploy.ts does the same work for either toolchain:

Reads the network from @uzolabs/sdk/chains and checks that the RPC reports the chain ID you asked for.
Checks that your wallet has gas. On mainnet it also asks you to type MAINNET.
Runs forge script script/Deploy.s.sol, or hardhat ignition deploy with --tool hardhat.
Confirms there is code at the new address.
Writes deployments/968.json, frontend/.env and frontend/src/abi.ts.

BOT Chain blocks have a base fee of 0. Hardhat Ignition reads that as free gas and would send a fee of 0, which the node rejects with “transaction underpriced”. scripts/lib/ignition-fees.ts is a Hardhat network hook, registered as the uzo-ignition-fees plugin, that fills in the fee the RPC asks for (20 gwei on testnet). Foundry gets this right on its own.

Verifying

scripts/verify.ts reads the address and constructor arguments from deployments/968.json and prints the command it runs. With Foundry:

Terminal

forge verify-contract <address> contracts/UzoToken.sol:UzoToken --chain 968 --verifier blockscout --verifier-url https://scan.bohr.life/api/ --watch --constructor-args <abi-encoded args>

With Hardhat:

Terminal

npx hardhat verify blockscout --network botTestnet <address> "Uzo Token" UZO 1000000000000000000000000 <owner address>

BOTScan runs Blockscout, so neither command needs an API key. See Verify contracts.

Sending from the command line

Terminal

npm run transfer -- 0xRecipientAddress 25

scripts/transfer.ts sends 25 tokens from your .env wallet and prints both balances before and after.

The web app

File	What it does
`frontend/src/wagmi.ts`	Sets up wagmi with the injected connector. With more than one wallet extension, “Connect wallet” lists each by name (EIP-6963)
`frontend/src/App.tsx`	Reads name, symbol, total supply, owner and your balance in one batched call, every 10 seconds, and sends transfers
`frontend/src/theme.css`	The Uzo Labs look: colours, cards and buttons in plain CSS
`frontend/src/styles.css`	Styles for this app only

Each transaction shows “confirm in wallet”, then “pending” with a BOTScan link, then “confirmed” or a readable error. Status lines sit in an aria-live region so screen readers announce them. The app doesn’t subscribe to events, because BOT Chain’s public RPCs don’t serve eth_getLogs. See Events without getLogs.

Using a local node

Set VITE_RPC_URL in frontend/.env to point the web app at another RPC, such as anvil --chain-id 968. The batched reads go through Multicall3, which a fresh anvil doesn’t have. Copy its code from testnet with cast code and set it with anvil_setCode.

Overview

Templates

Contributing

Token template walkthrough

Project layout

The contract

Tests

Two toolchains, one project

Deploying

Verifying

Sending from the command line

The web app

Using a local node

Next steps

Customize

USDT and decimals

​Project layout

​The contract

​Tests

​Two toolchains, one project

​Deploying

​Verifying

​Sending from the command line

​The web app

​Using a local node

​Next steps

Customize

USDT and decimals

Project layout

The contract

Tests

Two toolchains, one project

Deploying

Verifying

Sending from the command line

The web app

Using a local node

Next steps