Sundae V4 Launches on Cardano With Two RealFi Pools

Sundae Labs launched Sundae V4 on Cardano mainnet on October 1, 2026, opening two pools alongside RealFi’s mainnet debut. The deployment connects USDCx liquidity with RealFi’s new stablecoin and its staked counterpart.

SundaeSwap is a decentralized exchange on Cardano that enables token swaps and liquidity provision through smart contracts. V4 introduces configurable pool structures and a new order execution system.

Two RealFi Pools Start the V4 Rollout

Pi Lanningham, CTO of Sundae Labs, clarified that two V4 pools were live at launch: USDCx/USDrf Linear Swap and USDrf/sUSDrf stableswap. Sundae Labs described the release as a gradual rollout to support testing and its RealFi partnership.

RealFi issues $USDrf, a stablecoin designed to track the U.S. dollar with backing from real-world financial assets. Its staked counterpart, $sUSDrf, represents a share of the protocol’s staking vault.

RealFi calculates sUSDrf’s redemption value by dividing the value backing its staking vault by the number of sUSDrf tokens in circulation. As portfolio income is allocated, the amount of USDrf represented by each sUSDrf can increase.

This distinction shapes the two opening markets. USDCx/USDrf connects dollar assets at a fixed exchange ratio. USDrf/sUSDrf trades between the base stablecoin and a token with a changing redemption value.

According to Sundae Labs, the stableswap’s reference ratio follows that value as returns accrue. Movement in the reference ratio is separate from trading slippage, which occurs when an order pushes the pool away from its reference price.

Linear Swaps and Routing in One Transaction

The Linear Swap pool exchanges USDCx and USDrf at a 1:1 ratio with a predictable percentage fee. According to the team, increasing the order size does not move the exchange rate within available reserves.

A conventional constant product pool changes its quoted price as trades alter the balance between its assets. Linear Swap keeps the exchange ratio fixed. Sundae designed this model for stablecoin conversions in payment flows and other applications that require predictable amounts.

Its capacity depends on inventory. If demand drains one token from the pool, orders requiring that asset can no longer be filled there until reserves are replenished. The available balance limits execution without progressively worsening the exchange rate.

Lanningham said atomic routing connects the two opening pools within a single Cardano transaction. A USDCx to sUSDrf swap passes through the Linear Swap pool to obtain USDrf, then through the stableswap pool to obtain sUSDrf. The reverse route follows the same markets in the opposite direction.

The user submits one routed order, with both exchange steps settling together. This process purchases existing sUSDrf from pool liquidity. Depositing USDrf into RealFi’s staking vault and receiving newly issued sUSDrf remains a separate protocol operation.

Modular Pools and Further V4 Deployment

V4’s modular architecture separates a pool’s reserves and liquidity provider claims from configurable components such as pricing curves, execution rules, and permissions.

The design allows specialized markets to share Sundae’s interface and routing infrastructure. Builders can adapt pool behavior to an asset or product while connecting to the exchange’s existing order flow.

V4’s broader routing model allows orders to specify the desired asset and minimum output while execution searches available paths. Sundae states that any additional output produced through improved routing goes to the user.

The wider design includes concentrated liquidity, custom vaults, limit orders, and partial fills. Their mainnet availability was not confirmed in the initial launch announcements.

Access to the underlying tokens remains subject to RealFi’s eligibility rules. Its documentation excludes users in the United States, European Union, European Economic Area, United Kingdom, Hong Kong, and other restricted jurisdictions.

RealFi’s mainnet launch now has dedicated markets for both its base stablecoin and staked token on Sundae V4.