Create a Coin

Publishing a coin on Sui is nearly as straightforward as publishing a new type. The main difference is the requirement of a one-time witness when creating a coin.

module examples::mycoin {
    use std::option;
    use sui::coin;
    use sui::transfer;
    use sui::tx_context::{Self, TxContext};

    /// The type identifier of coin. The coin will have a type
    /// tag of kind: `Coin<package_object::mycoin::MYCOIN>`
    /// Make sure that the name of the type matches the module's name.
    struct MYCOIN has drop {}

    /// Module initializer is called once on module publish. A treasury
    /// cap is sent 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 on 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 TreasuryCap object as authorization.