Sui in one paragraph
Sui is a Layer 1 blockchain secured by delegated proof of stake. Validators process transactions, and SUI holders delegate stake to them through system transactions; stake changes and rewards are settled at epoch boundaries.[1]
The total supply of SUI on Mainnet is capped at 10,000,000,000 tokens. The token pays gas fees, backs validator stake and funds the storage fund that pays for data kept on chain.[1]
The source code is public in the MystenLabs/sui repository on GitHub, and its README points to the Sui Foundation for governance, decentralization and developer grants.[6]
See also: Sui project card · Best Layer 1 blockchains
Objects instead of account balances
On Ethereum, a token balance is a number inside a contract's storage. On Sui, the basic unit of storage is an object. Each object carries a 32-byte ID derived from the digest of the transaction that created it, an 8-byte version that increases every time a transaction modifies it, and the 32-byte digest of the last transaction that produced it.[2]
The docs list five ownership options. An address-owned object belongs to one 32-byte address. A consensus-address owned (party) object also has a single owner but is sequenced through consensus. A shared object can be used by anyone. An immutable object cannot be changed, transferred or deleted. A wrapped object sits inside another object's struct.[2]
Transactions form a graph: if an output object of transaction A is an input of transaction B, there is an edge from A to B. That graph is how Sui tracks which transactions depend on each other and which can run in parallel.[2]
Why declared inputs enable parallel execution
Move on Sui has no global storage. Every input object of a transaction is named up front by its unique ID, which lets the network schedule transactions with non-overlapping inputs in parallel. A payment that only touches coins you own does not contend with a trade in someone else's pool.[3]
Shared objects, like a DEX pool that many people trade against, are different: the order of transactions in the consensus output decides the order in which they operate on each shared object. Transactions touching different shared objects still execute in parallel on multiple cores. Developers choose the ownership type when they write the Move module, so contention is a design decision, not a network setting.[4]
Mysticeti consensus
Transactions are ordered by Mysticeti, a DAG-based Byzantine fault tolerant protocol. It needs only 3 rounds of messages to commit blocks, which the Sui docs say is the same as practical BFT and matches the theoretical minimum, and it lets multiple validators propose blocks in parallel.[4]
The docs report consensus commitment in about 0.5 seconds on average in benchmarks with sustained throughput of 200,000 transactions per second, 300,000 transactions per second with 10 nodes before latency crosses 1 second, and 400,000 with 50 nodes. The docs state these are controlled benchmark figures from the Mysticeti whitepaper, not production metrics.[4]
An epoch lasts about 24 hours on both Mainnet and Testnet. Validator set changes, staking, unstaking and the distribution of staking rewards are processed at epoch boundaries.[4]
Sui Move
Smart contracts on Sui are written in Sui Move, a variant of the Move language adapted to the object model. Assets are Move structs stored as objects, so the language's type rules decide what can be copied, dropped or transferred.[3]
The practical cost is porting. A Solidity contract from Ethereum cannot be deployed as is; it has to be rewritten in Move and redesigned around objects. Wallet support is also separate: Phantom's card lists Sui next to Solana, EVM networks and Bitcoin, while EVM-only wallets such as Rabby do not cover it.[3]
See also: Phantom wallet · Best software wallets
How a Sui gas fee is calculated
Sui publishes the formula in its docs: total gas fees = computation units x reference gas price + storage units x storage price. Computation is bucketed from 1,000 to 5,000,000 units, and a transaction above 5 million units aborts. Storage is linear at 100 storage units per byte.[5]
Worked example from the docs' own table: a basic transaction storing 10 bytes uses 1,000 computation units at a reference gas price of 1,000 MIST, plus 1,000 storage units at a storage price of 75 MIST, for 1,075,000 MIST in total. The docs give the minimum gas budget as 2,000 MIST (0.000002 SUI), which puts 1 SUI at 1 billion MIST, so this fee works out to 0.001075 SUI.[5]
The docs set the storage rebate at 99% of the storage fee paid. By that rate, deleting the object later would return 74,250 of the 75,000 MIST, and 750 MIST would stay non-rebateable. The minimum gas budget is 2,000 MIST.[5]
| Component | Units x price | Cost in MIST |
|---|---|---|
| Computation | 1,000 x 1,000 MIST | 1,000,000 |
| Storage | 1,000 x 75 MIST | 75,000 |
| Total fee | Computation + storage | 1,075,000 (0.001075 SUI) |
| Rebate if deleted | 99% of storage fee | 74,250 |
Staking, the storage fund and bridges
SUI holders stake by sending a transaction that calls the staking function in the system Move package. Rewards compound through a staking pool exchange rate that updates at each epoch boundary, and holders can withdraw or move stake before a new epoch begins. Reference gas prices are set at the start of each epoch, and the tokenomics docs say the reward distribution encourages validators to set low gas fees while operating with viable business models.[1]
Storage fees do not go straight to validators. They accumulate in the storage fund, which earns a share of staking rewards in proportion to its size relative to total stake. That is how Sui pays future validators for data written years earlier, and it is why deleting an object can refund most of its storage fee.[1]
Assets reach Sui from other chains through bridges. The Sui docs list four: the native Sui Bridge, which is operated and governed by Sui validators, plus Wormhole Connect, Wormhole Portal Bridge and ZetaChain. Each has its own supported assets, limits and finality rules, so check the docs page for the asset you plan to move.[7]
See also: Cross-chain bridges explained · Best bridges
The bottom line
Sui is worth learning if you build apps where most actions touch assets a single user owns, such as games or collectibles, because those transactions do not contend with other users' inputs. For DeFi pools and other shared state, order comes from Mysticeti, whose sub-second figures come from benchmarks. Check the storage part of gas before you design an app that writes a lot of data, since you pay for bytes up front and get 99% of that back only on deletion.[5]
Educational content, not financial advice. Crypto assets are volatile; do your own research.