Sui on Bitsy Wiki

The Object Model

Mon, 01 Jan 0001 00:00:00 +0000

Sui has no accounts holding balances in the Ethereum sense. Everything on-chain — coins, NFTs, AMM pools, published smart contract code, configuration — is a discrete, typed object. State is a graph of these objects rather than a global key-value store keyed by address.

Objects vs. the Account Model#

On Ethereum, a contract owns a slice of a single global storage trie. An ERC-20 balance is an entry in a mapping inside the token contract’s storage; the tokens are a number the contract attributes to an address. Reading or writing that mapping touches shared contract state, so the protocol cannot know in advance whether two transactions will collide — it must execute them one after another to be safe.

Sui Move

Mon, 01 Jan 0001 00:00:00 +0000

Move is a resource-oriented programming language created at Meta for the Diem (Libra) project. When that project wound down, the language survived its sponsor: it now underpins several chains, of which Sui is the most prominent. Sui Move is Mysten Labs’ dialect, adapted to fit Sui’s object model rather than the account storage of the original (“core”) Move and its other major descendant, Aptos Move. IOTA runs the same Mysten dialect, so the material here applies there too.

Programmable Transaction Blocks

Mon, 01 Jan 0001 00:00:00 +0000

A Programmable Transaction Block (PTB) is a single Sui transaction built as an ordered sequence of commands that execute atomically: either every command succeeds and the whole block commits, or any failure reverts the entire block. The defining feature is that the output of one command can be fed as the input to a later one. Results behave like registers — typed, transient values that live only for the duration of the transaction — so you can wire heterogeneous operations together: Move calls, object transfers, coin splits and merges, package publishing, and building Move vectors, all in one shot.

Consensus

Mon, 01 Jan 0001 00:00:00 +0000

Most blockchains funnel every transaction through a single global agreement step: validators must agree on one total order for all transactions before any of them execute. That step is the throughput bottleneck, and it is also where ordering games — front-running, sandwiching — become possible. Most transactions do not need a global order at all. Whether a transaction needs consensus depends entirely on the object model: specifically, whether it touches owned objects or shared objects.

Gas & Storage

Mon, 01 Jan 0001 00:00:00 +0000

Sui prices a transaction with two meters, not one. Every transaction pays a computation fee for the work the validators do, and a storage fee for the bytes it leaves behind on-chain. The two are quoted, accrued, and reasoned about independently. Ethereum bundles both into one volatile per-unit price set by an auction. Sui separates them because running a computation once and storing its output forever are different economic problems: one cost lands on the validators processing the transaction, the other on whoever is running the network years later.

zkLogin

Mon, 01 Jan 0001 00:00:00 +0000

zkLogin is Sui’s native primitive for controlling an on-chain address with an existing Web2 login. A user signs in with Google, Apple, Facebook, Twitch, or any other OpenID Connect provider, and from that login alone derives and operates a fully self-custodial Sui address — no seed phrase, no browser extension, no private key for the user to back up. It is the mechanism behind the onboarding pitch in the Sui overview: log in with Google, start transacting.

Walrus

Mon, 01 Jan 0001 00:00:00 +0000

Walrus is Mysten Labs’ decentralized blob-storage network, built to give Sui applications a place to put large data that no blockchain is designed to hold. It went to mainnet on March 27, 2025, alongside its native WAL token, and forms the storage leg of Sui’s emerging privacy-and-data stack.

The Problem#

On-chain state is expensive precisely because every validator stores and re-executes against it. Sui’s storage fund is engineered for small state — owned objects, balances, contract data — and prices it accordingly: every validator keeps a full copy forever. Putting megabytes of media, datasets, NFT artwork, website front-ends, AI model weights, or data-availability blobs through that mechanism is economically absurd.

DeFi on Sui

Mon, 01 Jan 0001 00:00:00 +0000

Sui’s DeFi ecosystem is young, fast-growing, and architecturally distinct from the EVM world. The object model and parallel execution that define the chain are not just performance footnotes here — they enable a class of on-chain primitive, the native order book, that is impractical on a globally-locked chain like Ethereum.

DeepBook — the native order book#

The flagship Sui DeFi primitive is DeepBook (now DeepBook v3), a fully on-chain central limit order book (CLOB) maintained by Mysten Labs. Rather than another application competing for users, DeepBook is positioned as a public good: a shared-liquidity layer that other protocols route through. Aggregators, AMMs, and wallets can all source liquidity from the same order book, so depth is pooled rather than fragmented across a dozen siloed pools.