What Is Soroswap? Stellar's Soroban AMM and Aggregator

Soroswap by the numbers (October 2026)

Measure	Value	Source
TVL	$1.21M	DefiLlama, 8 Oct 2026
Largest holdings	EURC $509K, USDC $396K, XLM $294K	DefiLlama
Peak TVL	$9.80M (18 Jul 2025)	DefiLlama
Pool volume, last 30 days	$15.2K	DefiLlama
Pool volume, last 12 months / all time	$18.4M / $36.0M	DefiLlama
Pairs created	214	Factory all_pairs_length
Protocol fee switch	Off	Factory fees_enabled
Active aggregator adapters	Soroswap, Phoenix, Aquarius	Aggregator get_adapters

The volume trend is stark. DefiLlama shows $8.4M of Soroswap pool volume in July 2025 and $4.7M in November 2025, then a slide to $221K in May 2026 and close to zero in June, July and September 2026. Over the same 30 days, Stellar DEX volume tracked by DefiLlama was about $96.4M, almost all of it on Aquarius. Network-wide context: Stellar DeFi TVL in 2026.

How to choose whether to use it

• You want to swap at the best price: the aggregator or API is the useful part, because it can reach Aquarius and Phoenix liquidity as well as Soroswap's own pools.
• You want to provide liquidity: the pools pay only the 0.30% fee, and with little volume that fee income is small. Compare with reward-paying pools in the best DEX on Stellar.
• You are building an app: the API offers quotes, routing, transaction building and sponsored trustlines behind a free API key.
• You want the fewest moving parts: a direct swap through the non-upgradeable router avoids the aggregator's extra contracts.

The AMM — pairs, factory and router

Soroswap's AMM is a Rust port of Uniswap V2. A factory creates one pair contract per token pair, each pair prices swaps with the constant-product formula x × y = k, and a router handles multi-hop swaps and slippage checks. The pair contract describes itself as a "constant product AMM with a .3% swap fee".

Liquidity providers deposit both tokens and receive pool tokens; the first deposit burns a minimum of 1,000 units of pool tokens, as in Uniswap, to limit rounding problems. The router can chain swaps through intermediate pairs (A to B to C) when no direct pool exists. The documentation's router page notes that it checks tokens against a list of known, validated assets to keep malicious tokens out of routes.

One Uniswap feature did not carry over in practice: the docs still include Uniswap's flash-swap page, but the Soroswap pair's swap function takes no callback data, so the flash swaps described there cannot be triggered through it. Pairs also follow Uniswap's accounting, in which tokens are sent to the pair first and the pair works out what arrived from its balances. Stellar Classic assets need a Stellar Asset Contract to be used in Soroban pools, which the app can create for you. Background on the platform: Soroban smart contracts.

Fees — fixed at 0.30%

Every swap pays 0.30% of the input, which is added to the pool's reserves and accrues to liquidity providers in proportion to their share. A protocol fee of 0.05%, a sixth of the total, can be switched on in the factory; it would come out of the LPs' share, not add to the trader's cost.

The fee is hard-coded in the pair contract (three thousandths of the input), so no governance vote can change it. The 0.05% switch follows Uniswap V2: when enabled, the protocol's cut is collected when liquidity is added or removed rather than on every swap. A read-only call to the factory on 8 October returned fees_enabled = false. For comparison, Aquarius pools choose from tiers between 0.01% and 1%.

The aggregator — splitting trades across AMMs

The Soroswap aggregator is a separate contract that splits one trade across several Soroban AMMs through adapter contracts, using a distribution worked out off-chain. On 8 October 2026 its on-chain registry held three unpaused adapters: Soroswap, Phoenix and Aquarius. Its code also defines Comet, but no Comet adapter was registered.

The documentation lags the chain. One page labels Aquarius "Coming Soon" and another "currently in testing", which is why an issue filed in Soroswap's docs repository on 17 September 2026 pointed out that the mainnet Phoenix and Aquarius adapters were already configured and unpaused. We re-ran the same get_adapters call and got the same answer. The aggregator excludes the Stellar DEX order book because, in the docs' words, it is "incompatible with Soroban smart contracts".

DefiLlama does not list a separate Soroswap aggregator volume series for Stellar; the two aggregators it tracks there, BIM and LumAgg, handled about $90K and $40K over 30 days. Volume Soroswap routes into Aquarius pools is counted as Aquarius volume.

The API — quotes, routes and sponsored trustlines

The Soroswap API is what wallets and apps integrate. It returns quotes and optimal routes across Soroswap, Phoenix, Aquarius and the Stellar DEX, builds the transaction for the user to sign, and can submit it. Access needs a free API key.

Its most practical feature for new users is "Gasless Trustline". A sponsor account fronts the roughly 0.5 XLM reserve for a trustline the user does not have yet, and the user repays it inside the same swap, so someone holding only bridged USDC can receive a new asset without first acquiring XLM. It runs on the Stellar DEX through path payments and applies only to a user's first swap into an asset. The trustline mechanics are covered in Stellar transaction fees.

Audits and upgradeability

OtterSec audited the core contracts in February 2024 and Runtime Verification audited the aggregator in August 2024; both reports are in Soroswap's GitHub. The two layers differ on upgrades: the pair, factory and router contracts contain no upgrade function, while the aggregator has one that only its admin can call.

That split is reasonable. Pools that hold LP money cannot be changed underneath their depositors; the routing layer, which holds nothing between transactions, can be fixed or extended. The aggregator's own disclaimer spells out the remaining risk: it calls other protocols' contracts, those protocols or tokens "may upgrade their WebAssembly (WASM) code", and a transaction that passes its checks could still lose funds if a called contract turned malicious. What an audit does and does not cover: smart contract audits.

Who builds it

Soroswap is developed by PaltaLabs, a Latin America-based blockchain studio, and its code is open source under the Apache 2.0 licence. The same team builds DeFindex, the Stellar vault infrastructure, and the two connect: DeFindex's Blend strategy sells its BLND rewards on Soroswap before re-supplying the proceeds.

That link is one reason Soroswap still matters with small TVL. Its router is a dependency for other products, and its API sits behind several wallets' swap screens. For how DeFindex uses it, see what is DeFindex.

Risks

• Thin liquidity. With $1.2M across 214 pairs, many pools are tiny. A direct swap in a small pool can lose far more to price impact than to the fee.
• Low LP income. Fee revenue scales with volume, and tracked volume has been near zero for months.
• Aggregator dependency. Routed trades inherit the risk of every adapter, pool and token they touch, and the aggregator itself is upgradeable by its admin.
• Documentation drift. Pages disagree on which venues the aggregator uses; check on-chain state or the API rather than the docs.
• Token risk. Anyone can create a pair for any token. Check the issuer before buying.

How the pieces fit together

Soroswap began as Stellar's first Soroban AMM and has turned into routing infrastructure. Its pools are simple and immutable, but liquidity moved to Aquarius, where AQUA emissions pay LPs to stay. The aggregator and API now treat Aquarius and Phoenix as sources, and products such as DeFindex rely on the router for reward swaps. Users can reach Soroswap without opening its app.

The takeaway

Use Soroswap as a router, not as a place to park liquidity. Its contracts are among the simplest and best-audited on Stellar, and its aggregator can find better prices by reaching other AMMs. Its own pools are too thin, and too quiet, to pay LPs much until volume returns.

Sources: DefiLlama protocol, summary/dexs/soroswap and overview/dexs and aggregators endpoints, 8 October 2026; read-only simulations of the Soroswap factory (all_pairs_length, fees_enabled) and aggregator (get_adapters), 8 October 2026; Soroswap documentation (fees, router, SDEX, aggregator, supported AMMs, audits, disclaimer, API, gasless trustline, about us); github.com/soroswap/core and soroswap/aggregator source and audit reports; soroswap/docs issue #47.