Overview
Atomic Swap is a peer-to-peer trading tool that lets two Cardano wallets exchange any mix of tokens and NFTs in a single move. Both sides sign the same trade, so either everyone walks away with what they agreed to, or nothing happens at all1. There is no listings page, no public order book, and no middleman holding the goods. The two traders agree directly, then settle on the blockchain in one shot.
Atomic Swap is built and maintained by Frank Hampus Weslien as a solo project2. Instead of running its own DApp code on Cardano, it uses a built-in feature of the network that requires two signatures on the same transaction before anything moves. The full trading history is visible at the project's proof address on Cardanoscan, where every completed swap shows up as a regular Cardano transaction1.
Key Features
- A trade only happens when both sides have signed. The assets sit safely in each wallet until everyone has agreed and signed the same transaction. Neither side can run off with the other's goods part way through1.
- Flat fee of 2 ADA per trade, split down the middle. Each side pays 1 ADA, no matter how many items are in the swap. There is no percentage cut and no extra charge for bigger trades2.
- No custom code to trust. The trade uses a standard Cardano network feature instead of bespoke smart contract code, which removes one common source of bugs and exploits1.
- Open source and free to host yourself. The full TypeScript code is published on GitHub under the GPL-3.0 license, so anyone can read it, copy it, or run their own version34.
- Public proof of every trade. Every completed swap lands on a public Cardanoscan address listed in the whitepaper, so the project's actual use is verifiable rather than just self-reported1.
What to Expect
Atomic Swap is for people who want to barter assets directly instead of listing them on a public marketplace. A typical use is trading one NFT for another, or moving a bundle of tokens between two friends or two project treasuries. You open a trading session in your browser, connect a Cardano wallet, agree on the contents with the other party, and sign once.
For organizations and project teams, the appeal is moving several assets between treasuries in one clean step, with no need to set up an escrow service. For developers, the project doubles as a working example: the whitepaper walks through the underlying transaction it builds, and the GitHub repository contains the full TypeScript client.
A small caveat for anyone digging in: the on-site FAQ still answers an older version of the question "is this open source?" with no. The changelog and the public GitHub repo are the up-to-date answer. Treat them as the source of truth rather than the older FAQ entry.
