Assets

Native programmable assets are a core concept in MOI. Asset rules (minting, burning, transfers, approvals) are enforced at the protocol level through asset logic written in Coco.

Asset Logic

Declare an asset logic with the asset keyword:

coco asset MyToken

Asset logic has privileged access to the asset engine via the asset global object.

Asset Engine Methods

Lifecycle

Method	Description
asset.Define(symbol, decimals, manager, creator, max_supply, enable_events)	Define asset properties (call in deploy)

Transfers & Ownership

Method	Description
asset.Transfer(token_id, beneficiary, amount)	Transfer from Sender to beneficiary
asset.TransferFrom(token_id, benefactor, beneficiary, amount)	Transfer from benefactor (requires approval)
asset.Mint(token_id, beneficiary, amount)	Mint new tokens
asset.MintWithMetadata(token_id, beneficiary, amount, static_metadata)	Mint with metadata
asset.Burn(token_id, amount)	Burn tokens from Sender
asset.Lockup(token_id, beneficiary, amount)	Lock tokens
asset.Release(token_id, benefactor, beneficiary, amount)	Release locked tokens
asset.Approve(token_id, beneficiary, amount, expires_at)	Approve spending
asset.Revoke(token_id, beneficiary)	Revoke approval

Queries

Method	Returns	Description
asset.BalanceOf(token_id, address)	U256	Balance of address
asset.Symbol()	String	Asset symbol
asset.Creator()	Identifier	Creator address
asset.Manager()	Identifier	Manager address
asset.Decimals()	U64	Decimal places
asset.MaxSupply()	U256	Maximum supply
asset.CirculatingSupply()	U256	Current supply
asset.EnableEvents()	Bool	Whether events enabled

Metadata

Method	Description
asset.SetStaticMetadata(key, value)	Set asset-level static metadata
asset.SetDynamicMetadata(key, value)	Set asset-level dynamic metadata
asset.GetStaticMetadata(key)	Read static metadata → Bytes
asset.GetDynamicMetadata(key)	Read dynamic metadata → Bytes
asset.SetStaticTokenMetadata(token_id, key, value)	Per-token static metadata
asset.SetDynamicTokenMetadata(token_id, key, value)	Per-token dynamic metadata
asset.GetStaticTokenMetadata(token_id, key)	Read per-token static → Bytes
asset.GetDynamicTokenMetadata(token_id, key)	Read per-token dynamic → Bytes

Example

my_token.coco

coco asset MyToken

event TransferEvent:
    topic from Identifier
    topic to Identifier
    field amount U256

endpoint Transfer(to Identifier, amount U256):
    if asset.EnableEvents():
        emit TransferEvent{from: Sender, to: to, amount: amount}

    asset.Transfer(token_id: 0, beneficiary: to, amount: amount)

endpoint Mint(to Identifier, amount U256):
    if Sender != asset.Manager():
        throw "Unauthorized"

    asset.Mint(token_id: 0, beneficiary: to, amount: amount)

Calling Asset Logic

Regular logic cannot access the asset engine directly. It must call asset logic through an interface.

payment.coco

coco Payment

interface Token:
    asset:
        Transfer(to Identifier, amount U256)

endpoint Pay(token_id Identifier, recipient Identifier, amount U256):
    memory token = Token(token_id)
    token.Transfer(to: recipient, amount: amount)

Creating Assets

Assets are created via MOI interactions, not directly in Coco. In Cocolab:

compile MyToken from manifest(mytoken.yaml)
create MyToken(symbol: "MTK", decimals: 18, manager: user1, max_supply: 1000000)

Key Points

• Only asset logic can access the asset global object
• Regular logic must use interfaces to interact with assets
• This separation ensures security and programmability