Icon LinkSupply Functionality

For implementation details on the Asset Library supply functionality please see the Sway Libs Docs Icon Link.

Icon LinkImporting the Asset Library Supply Functionality

In order to use the supply functionality of the Asset Library, the Asset Library and the SRC-3 Icon Link Standard must be added to your Forc.toml file and then imported into your Sway project.

To add the Asset Library and the SRC-3 Icon Link Standard as a dependency to your Forc.toml file in your project, use the forc add command.

forc add [email protected]
forc add [email protected]

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NOTE: Be sure to set the version to the latest release.

To import the Asset Library Supply Functionality and SRC-3 Icon Link Standard to your Sway Smart Contract, add the following to your Sway file:

use asset::supply::*;
use src3::*;

Icon LinkIntegration with the SRC-3 Standard

The SRC-3 Icon Link definition states that the following abi implementation is required for any Native Asset on Fuel which mints and burns tokens:

abi SRC3 {
    #[storage(read, write)]
    fn mint(recipient: Identity, sub_id: Option<SubId>, amount: u64);
    #[payable]
    #[storage(read, write)]
    fn burn(vault_sub_id: SubId, amount: u64);
}

The Asset Library has the following complimentary functions for each function in the SRC3 abi:

• _mint()
• _burn()

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NOTE The _mint() and _burn() functions will mint and burn assets unconditionally. External checks should be applied to restrict the minting and burning of assets.

Icon LinkSetting Up Storage

Once imported, the Asset Library's supply functionality should be available. To use them, be sure to add the storage block below to your contract which enables the SRC-3 Icon Link standard.

storage {
    total_assets: u64 = 0,
    total_supply: StorageMap<AssetId, u64> = StorageMap {},
}

Icon LinkImplementing the SRC-3 Standard with the Asset Library

To use either function, simply pass the StorageKey from the prescribed storage block. The example below shows the implementation of the SRC-3 Icon Link standard in combination with the Asset Library with no user defined restrictions or custom functionality. It is recommended that the Ownership Library is used in conjunction with the Asset Library's supply functionality to ensure only a single user has permissions to mint an Asset.

The _mint() and _burn() functions follows the SRC-20 standard for logging and will emit the TotalSupplyEvent when called.

use asset::supply::{_burn, _mint};
use src3::SRC3;
 
storage {
    total_assets: u64 = 0,
    total_supply: StorageMap<AssetId, u64> = StorageMap {},
}
 
// Implement the SRC-3 Standard for this contract
impl SRC3 for Contract {
    #[storage(read, write)]
    fn mint(recipient: Identity, sub_id: Option<SubId>, amount: u64) {
        // Pass the StorageKeys to the `_mint()` function from the Asset Library.
        _mint(
            storage
                .total_assets,
            storage
                .total_supply,
            recipient,
            sub_id
                .unwrap_or(b256::zero()),
            amount,
        );
    }
 
    // Pass the StorageKeys to the `_burn_()` function from the Asset Library.
    #[payable]
    #[storage(read, write)]
    fn burn(sub_id: SubId, amount: u64) {
        _burn(storage.total_supply, sub_id, amount);
    }
}

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NOTE The _mint() and _burn() functions will mint and burn assets unconditionally. External checks should be applied to restrict the minting and burning of assets.