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Creating a Custom Coin in Sui

In this tutorial, we will demonstrate how to create a custom coin in Sui. The process is relatively simple and requires using a One Time Witness. We will create a new coin type and initialize a treasury cap to control the minting and burning of the custom coin.

Follow these steps to create a custom coin:

  1. Create the mycoin module: Define a new module examples::mycoin to create the custom coin.
module examples::mycoin {
    use std::option;
    use sui::coin;
    use sui::transfer;
    use sui::tx_context::{Self, TxContext};
}
  1. Define the MYCOIN struct: Create a MYCOIN struct as the type identifier of the custom coin.
struct MYCOIN has drop {}
  1. Create the module initializer: Define the init function, which is called once on module publish. The function takes a witness and a mutable transaction context as arguments. It creates a treasury cap and a metadata object, and sends the treasury cap to the publisher, who then controls minting and burning.
fun init(witness: MYCOIN, ctx: &mut TxContext) {
    let (treasury, metadata) = coin::create_currency(witness, 6, b"MYCOIN", b"", b"", option::none(), ctx);
    transfer::public_freeze_object(metadata);
    transfer::public_transfer(treasury, tx_context::sender(ctx))
}

The Coin<T> is a generic implementation of a coin in Sui. The owner of the TreasuryCap gets control over the minting and burning of coins. Further transactions can be sent directly to the sui::coin::Coin with the TreasuryCap object as authorization.

Now you have successfully created a custom coin in Sui. The publisher can control the minting and burning of the coin using the TreasuryCap.