Overview
FeesaSwap is a fee-payment tool that lets Cardano users pay transaction fees in supported tokens instead of ADA. Token holders who do not yet have ADA can sign a transaction with the token they already have; FeesaSwap quietly swaps a slice of it for ADA, pays the network fee, and submits the transaction in one step. It is positioned as infrastructure that any wallet or app can plug into so its users get the same convenience without leaving the app.
On Cardano, every transaction needs a small amount of ADA to cover the network fee. New users who arrive holding only a project's own token usually have to detour through an exchange just to buy enough ADA to start. FeesaSwap is built by MLabs and runs on Cardano mainnet, with an underlying smart contract referred to in its documentation as Pisa.
Key Features
- One-step token-only payments. A user signs a transaction with their token, and FeesaSwap automatically converts enough of it to ADA, settles the fee, and submits the transaction — no separate swap or wallet preload.
- Shared liquidity market. Liquidity providers post a single position to an open on-chain pool, and any FeesaSwap-integrated wallet or app can draw on that liquidity, instead of every project running its own private fee fund.
- Drop-in React component. Builders can install @mlabs-haskell/feesaswap-components — a packaged interface element that handles wallet selection, the underlying swap, and submission with a few lines of code.
- Underlying SDK for any stack. A separate SDK package serves projects that do not use React, exposing the same functionality through a more general programming interface.
- Multiple network support. The component works against Cardano mainnet as well as the preprod and preview test networks, so teams can build and test before going live.
What to Expect
The home page at feesaswap.io is a one-page site aimed at developers, with a short three-step explainer, a "Connect Wallet" demo, and a code snippet showing how to embed the React component. Listed wallets include Lace, Eternl, and VESPR, with more noted as coming. Day-to-day, most people will encounter FeesaSwap not on this page but inside another app or wallet that has integrated it: the experience is meant to feel like paying a fee normally, with the difference being that the wallet shows the fee in the token being used.
For builders, the integration documentation explains the four-step balancing flow — building an unbalanced transaction, picking a liquidity position, sending the transaction to the FeesaSwap balancer service, and signing and submitting the result. The user-facing component and SDK are published as open source under the MIT license. The team has said in its Project Catalyst Fund 15 proposal that the protocol is being arranged for an external CertiK audit; a public audit report has not yet been identified.
