sui-move-object

1. Structs

All structs must be declared public. Ability declarations go after the fields:

// ✅
public struct Pool has key {
    id: UID,
    balance_x: Balance<SUI>,
    balance_y: Balance<USDC>,
}

public struct PoolCap has key, store {
    id: UID,
    pool_id: ID,
}

// ❌ Legacy — no public keyword
struct Pool has key {
    id: UID,
}

Object rule: Any struct with the key ability must have id: UID as its first field. Use object::new(ctx) to create UIDs — never reuse or fabricate them.

Naming conventions

Capabilities must be suffixed with Cap:

// ✅
public struct AdminCap has key, store { id: UID }

// ❌ Unclear it's a capability
public struct Admin has key, store { id: UID }

No Potato suffix — a struct's lack of abilities already communicates it's a hot potato:

// ✅
public struct Promise {}

// ❌
public struct PromisePotato {}

Events named in past tense — they describe something that already happened:

// ✅
public struct LiquidityAdded has copy, drop { ... }
public struct FeesCollected has copy, drop { ... }

// ❌
public struct AddLiquidity has copy, drop { ... }
public struct CollectFees has copy, drop { ... }

Dynamic field keys — use positional structs (no named fields):

// ✅
public struct BalanceKey() has copy, drop, store;

// ⚠️ Acceptable but not canonical
public struct BalanceKey has copy, drop, store {}

Constants naming

Error constants use EPascalCase. All other constants use ALL_CAPS:

// ✅
const ENotAuthorized: u64 = 0;
const MAX_FEE_BPS: u64 = 10_000;

// ❌
const NOT_AUTHORIZED: u64 = 0;   // error should be EPascalCase
const MaxFeeBps: u64 = 10_000;   // non-error should be ALL_CAPS

2. Object Abilities Cheat Sheet