Welcome to the NZRT Wiki Podcast. Today we’re looking at ERC-20 Tokens.

So, what exactly is ERC-20? It’s the standard that Ethereum uses for fungible tokens. Fungible just means that every token is identical and interchangeable — one ITSL token is worth exactly the same as any other ITSL token, the same way one dollar bill is the same as any other dollar bill. At NZRT, ERC-20 is directly relevant because our ITSL token is built on this standard and lives on the Base network, which is an Ethereum Layer 2 chain.

Now, the ERC-20 standard defines a set of functions that every compliant token contract must include. Think of these as a minimum feature set — a kind of API contract that lets wallets, exchanges, and other smart contracts interact with your token without needing to know anything else about it. Let’s walk through each one.

First, there’s total supply. This does exactly what it sounds like — it tells you how many tokens exist in total. Then there’s balance of, which takes an address and returns how many tokens that address holds. So if you want to check your own token balance, this is the function doing that work under the hood.

Next is transfer. This is how you send tokens directly from your own wallet to someone else’s. You provide the recipient’s address and the amount, and the tokens move. Then there’s approve, which is where things get a little more interesting. Approve lets you authorise a third party — called a spender — to use up to a certain number of your tokens on your behalf. This is critical for things like decentralised exchanges, where a smart contract needs permission to move your tokens without you handing over full control of your wallet.

Closely related to approve is allowance. This function lets you check how many tokens a spender is still authorised to use. So if you approved someone to spend a hundred tokens and they’ve already used thirty, allowance would come back with seventy.

Finally, there’s transfer from. This is the function that actually executes a third-party transfer — the spender you previously approved uses this to move tokens from your address to another one, within the limit you already set.

On top of these functions, ERC-20 also defines two events. An event called Transfer fires every time tokens move between addresses, and an event called Approval fires whenever an approval is granted. These events are how external tools like block explorers and wallets track activity on-chain without having to read every piece of contract state directly.

Now let’s look at how NZRT’s own ITSL token is implemented. The contract code shows a Solidity smart contract that extends two components from the OpenZeppelin library — the standard ERC-20 base contract, and an Ownable module that restricts certain privileged actions to the contract’s owner. The constructor sets the token’s name to Iteasel Token and its symbol to ITSL, assigns ownership to whoever deploys the contract, and immediately mints the full initial token supply to that same deployer address. The supply calculation accounts for decimals by multiplying the number you pass in by ten to the power of eighteen — which brings us neatly to the token’s properties.

The ITSL token has a name of Iteasel Token, a ticker symbol of ITSL, and uses eighteen decimal places. That’s the default for ERC-20 tokens, and it means one token is stored on-chain as a whole number with eighteen zeros behind it. This is how you get precise fractional amounts when transacting. The token lives on Base Mainnet and is built using the OpenZeppelin ERC-20 implementation, which is the industry-standard audited library for this kind of contract.

There is also a mint function in the contract. This is a post-deployment function that only the contract owner can call. It lets the owner create and send additional tokens to any address at any time after launch — useful if you need to distribute tokens in stages rather than all at once at deployment.

If you want to go deeper, the wiki cross-references three related topics: OpenZeppelin, which provides the base contract code; the ITSL Token page, which covers deployment specifics and tokenomics in more detail; and the Contract Deployment page, which walks you through the process of actually getting a contract live on the Base network.

That’s it for this episode of the NZRT Wiki Podcast. Thanks for listening.