Icon LinkSRC-8: Bridged Asset

The following standard attempts to define the retrieval of relevant on-chain metadata for any bridged Native Assets Icon Link. Any contract that implements the SRC-8 standard MUST implement the SRC-7 and SRC-20 standards.

Icon LinkMotivation

The SRC-8 standard seeks to enable relevant data for bridged assets on the Fuel Network. This data includes the origin chain, address, ID, decimals, and any arbitrary data. All metadata queries are done through a single function to facilitate cross-contract calls.

Icon LinkPrior Art

The use of generic metadata for Native Assets Icon Link is defined in the SRC-7 standard. This standard integrates into the existing SRC-7 standard.

Icon LinkSpecification

Icon LinkAsset Creation

The SubId of the asset MUST be the digest of the sha256(origin_chain_id, origin_asset_address, origin_asset_id) hash where:

• origin_chain_id is a String of the chain ID where the asset was originally minted.
• origin_asset_address is a b256 of the asset's address on the chain where the asset was originally minted.
• origin_asset_id is a b256 of the asset's ID such as an NFT's ID on the chain where the asset was originally minted. IF there is no ID, b256::zero() SHALL be used.

Icon LinkSRC-20 Metadata

Any bridged assets MUST use the name and symbol of the asset on the chain where the asset was originally minted.

Icon LinkSRC-7 Metadata

Icon Linkbridged:chain

The key bridged:chain SHALL return an String variant of the chain ID where the asset was originally minted.

Icon Linkbridged:address

The key bridged:address SHALL return a B256 variant of the asset's address on the chain where the asset was originally minted. Native assets of a chain that do not have an address such as Ether on Ethereum SHALL use b256::zero().

Icon Linkbridged:id

The key bridged:id MAY return a B256 variant of the asset's ID such as an NFT's ID on the chain where the asset was originally minted. IF there is no ID, None SHALL be returned.

Icon Linkbridged:decimals

The key bridged:decimals MAY return an Int variant of the asset's decimals on the chain where the asset was originally minted. IF there are no decimals, None SHALL be returned.

Icon LinkRationale

The SRC-8 standard should allow for data on any bridged assets on the Fuel Network. This standard builds off existing standards and should allow other contracts to query any relevant information on the bridged asset.

Icon LinkBackwards Compatibility

This standard is compatible with Fuel's Native Assets Icon Link, the SRC-20 standard, and the SRC-7 standard.

The standard is also compatible with both tokens and NFTs native to other ecosystems by introducing a token ID element of the original chain.

Icon LinkSecurity Considerations

This standard does not call external contracts, nor does it define any mutations of the contract state.

Icon LinkExample

impl SRC7 for Contract {
    fn metadata(asset: AssetId, key: String) -> Option<Metadata> {
        if (asset != AssetId::default()) {
            return Option::None;
        }
 
        match key {
            String::from_ascii_str("bridged:chain") => {
                Option::Some(String::from_ascii_str("1"))
            },
            String::from_ascii_str("bridged:address") => {
                let origin_asset_address = b256::zero();
                Option::Some(Metadata::B256(origin_asset_address))
            },
            String::from_ascii_str("bridged:id") => {
                let origin_asset_id = b256::zero();
                Option::Some(Metadata::B256(origin_asset_id))
            },
            String::from_ascii_str("bridged:decimals") => {
                Option::Some(Metadata::Int(1))
            },
            _ => Option::None,
        }
    }
}
 
impl SRC20 for Contract {
    fn total_assets() -> u64 {
        1
    }         
 
    fn total_supply(asset: AssetId) -> Option<u64> {
        match asset { 
            AssetId::default() => Option::Some(1),
            _ => Option::None,
        }
    }
 
    fn name(asset: AssetId) -> Option<String> {
        match asset { 
            AssetId::default() => Option::Some(String::from_ascii_str("Name")),
            _ => Option::None,
        }
    }
 
    fn symbol(asset: AssetId) -> Option<String> {
        match asset { 
            AssetId::default() => Option::Some(String::from_ascii_str("Symbol")),
            _ => Option::None,
        }
    }
 
    fn decimals(asset: AssetId) -> Option<u8> {
        match asset { 
            AssetId::default() => Option::Some(0u8),
            _ => Option::None,
        }
    }
}