What Is SunSwap? How TRON's AMM Exchange Works

SunSwap is the trading layer of SUN.io. SUN.io describes itself as a single DeFi platform on TRON for swaps, stablecoin swaps, liquidity mining and governance ¹. The platform started in September 2020 as a SUN token mining program. It merged in JustSwap, TRON's earlier DEX, in October 2021 ².

The Terms of Use say the website is provided by the "SUN team" and that the interface runs on facilities in Singapore ⁸. They also say the team is not registered with the Monetary Authority of Singapore. No incorporated company, address or registration number is given. The Terms separate the website (the "interface") from the SUN protocol, which they describe as open-source or source-available software running on the blockchain ⁸.

The design follows the AMM model used by Uniswap. Prices come from pool balances, not an order book. See what a DEX is for the general mechanism.

1. Get a TRON wallet. The docs use TronLink as the example. Any wallet that supports TRON and connects to sun.io works ⁵.
2. Connect the wallet on sun.io.
3. Pick the tokens and amount. The Smart Router shows the expected output and the route. You can inspect the route before you confirm ⁵.
4. Approve the token the first time you sell it. This gives the contract permission to move that token from your wallet ⁵.
5. Confirm and sign. The trade settles on TRON within seconds ⁵.

Approvals stay in place after the swap. If a contract you approved were ever compromised, it could move the approved token. Revoking unused approvals limits that exposure.

SunSwap fees go to liquidity providers and, in some versions, to SUN buybacks. They depend on the pool you trade through ³⁴:

On top of the pool fee, every TRON transaction uses network resources (energy and bandwidth). If your wallet hasn't staked TRX for those resources, they are paid in TRX ⁴. Large trades in shallow pools also lose value to price impact, which is separate from the fee. On V4 pools with dynamic fees, high price impact raises the fee itself ⁴.

SUN DAO governs SUN.io. To vote, you lock SUN and receive veSUN. One veSUN equals one vote ⁷. A proposal needs a creator holding more than 30 million veSUN. It passes if yes votes exceed 90 million and outnumber no votes. The cycle is a two-day review, a three-day vote and a two-day lock before execution ⁷. veSUN holders also vote on liquidity-mining weights and receive half of the stablecoin-pool fees ¹.

Part of the protocol's revenue goes to buying back SUN and burning it, as listed in the fee table above ³.

The Terms of Use (January 2022, the only version found) bar sanctioned persons. They also bar citizens, residents and organizations of mainland China, Taiwan, Hong Kong, the United States and Singapore ⁸. Users must be of legal age in their jurisdiction, and the Terms say the interface may not be available elsewhere ⁸. Because the contracts are on-chain, they can be reached without the sun.io site. The Terms still apply to anyone using the site.

There is no account or identity check. The site does log your wallet address, transaction hashes and the tokens you trade. It uses TronGrid, Cloudflare and Google Analytics, and it may share data with blockchain-analytics firms to detect financial crime ⁸.

SUN.io states that its smart contracts were audited by SlowMist. It adds that an audit cannot remove risk and advises against depositing funds you cannot afford to lose ⁶. The docs link no public report, date or scope for that audit.

Risks to weigh:

• Smart-contract risk. Pools, routers and hooks are code. V4 hooks add custom logic per pool.
• Token risk. Anyone can create a pool for any TRC-20 token, including copies of real tokens. SunPump launches add many new, thinly traded tokens. Check the contract address, not just the ticker.
• Liquidity-provider risk. Impermanent loss applies. On V3/V4, a position stops earning fees when the price leaves its range. SunCurve LPs face permanent depeg risk if a stablecoin loses its peg ⁶.
• Chain dependence. SunSwap runs only on TRON. If the network stalls, so does trading (see the incident record).
• Phishing. The official domain is sun.io. Fake "SunSwap" sites and support accounts ask for seed phrases. No real service does. See how to avoid crypto scams.

The Terms cap the team's liability at the amount you paid it or $100, whichever is higher. Disputes go to binding arbitration in Singapore, and class actions are waived ⁸.