Types

TREA is statically typed.

Primitive Types

bool
u8
u16
u32
u64
u128
u256
i64
i128
Address
String
AssetId
Hash256
Percent

Address is a real account or contract address. It is non-zero by default: runtime effects and storage writes reject the empty/zero address. Do not use a zero address as an absence marker or burn sink; model absence with explicit state, and use ledger burn/retirement mechanisms for destruction.

Financial Types

Money[ASSET]
Account[ASSET]

Money[...] exists in the type system, but the executable safety envelope rejects it in:

• public ABI;
• executable storage;
• typed executable local bindings.

For current executable contracts, represent amounts as integers and use posting helpers for accounting meaning.

Collections

Vec[T, MAX]
Map[K, V]
Map[K, V, MAX_ENTRIES]

Use bounded collection forms for runtime safety. Sparse map and vector storage is supported.

Nested `Map` (`Map[K, Map[...], N]`) is not supported on the IR runtime (the backend used by IrContractInstance, the default for new contracts compiled via compile_contract/compile_contract_artifact and executed at runtime). The verifier rejects it at IrContractInstance::new(...) time with a clear "nested Map storage is not supported" error rather than letting it fail silently at read/write time. Instead, model the second key dimension with a composite/derived key in a single Map, e.g.:

storage:
    beneficiary_category_funded: Map[Address, u128, 4096]

def derived_key(category: Address, beneficiary: Address) -> Address:
    return derive_child_id(category, beneficiary, "cap_v1")

or split the nested dimension into a child contract instead. The legacy ContractInstance evaluator (used by hand-written fixtures such as BasicToken/ERC20) does support nested Map — but new contracts should not rely on it, since the IR backend is the supported execution path going forward. See issue #54.

Structs

Struct[Name{field: Type, other: Type}]

Structs group related fields under a single storage variable.

storage:
    terms: Struct[LoanTerms{
        principal: u128,
        rate_ppm: u64,
        active: bool
    }]

Access struct fields with .:

self.terms.principal
self.terms.active = True

Restrictions:

• Structs are for storage and internal contract use only.
• Structs cannot appear in public entrypoint parameters or return values.
• Money[...] inside a struct field is rejected by the compiler.

ABI Types

Public entrypoint parameters and returns should use currently executable types such as:

• bool;
• unsigned/signed integers;
• Address;
• String;
• AssetId;
• Hash256;
• Percent.

Do not expose Money[...] in a public entrypoint.