Building an NFT Marketplace with JamOnBread's Smart Contract

Technology 13.05.2024

We've set ourselves on a mission to not only build a sweet marketplace for the community but also provide SDKs and tooling for builders to utilize our solutions and smart contracts. Thanks to the revenue-sharing smart contracts, our approach is more universal and easily adoptable by anyone in Cardano and beyond.

Current meta

As you can see below, there are several obstacles when building a new marketplace on Cardano. Each new marketplace has to build the backend and frontend for their platform and design, develop, and audit their own smart contracts - the current meta is that each marketplace must have its own smart contract to earn revenues from sales. Marketplaces can aggregate listings from other marketplace's smart contracts, but when those sell, they don't earn any revenue as it always goes back to the marketplace that deployed the smart contract on the blockchain.

This design ultimately forces the marketplace to either utilize another marketplace's smart contract but have no revenue from it, or go through the long and expensive route to develop and audit its own smart contract. But the journey doesn't end here - actually earning revenue requires significant marketing efforts to attract people to trade the NFTs through their own smart contract. Additionally, if each marketplace uses different smart contracts, users would have to check all marketplaces separately as the listings would be isolated and market disconnected.

Different approach

We didn't like this design as it's gatekeeping from new builders and businesses and leads to the monopolized market. We've decided to go through the hard route to design, develop, and audit our own smart contracts, but only so the next marketplaces don't have to. Our design is slightly different.

The goal for us was to create a more universal smart contract that can be utilized by absolutely anyone. We've made the design so it's capable of sharing revenue with all sales contributors, ensuring anyone can utilize it and get a fair share of the service fee for doing so.

How does it work? The smart contract can recognize on which marketplace the NFT was listed and on which marketplace the NFT got sold. Once the trade happens, it shares the revenue among the two parties in a fair manner. If both actions happen on one marketplace, it keeps both of the parts. There is more to the revenue sharing as it also has an on-chain affiliate layer on top of it, but for the sake of this article, let's keep it simpler for now—you can read more in our GitBook.


The calculation for the price is 100 ADA, and a typical set of treasuries and 5% royalty:

  • 92.5 ADA to the seller
  • 1 ADA to the marketplace where NFT was listed
  • 1.25 ADA to the marketplace where NFT was sold
  • 0.25 ADA to JoB treasury
  • 5 ADA to project royalties

Why is it innovative? When a new marketplace wants to enter the market, the entry barriers are extremely high as we mentioned above. Thanks to the revenue sharing, they can simply utilize our smart contract for their platform, instantly access all the listings that are in the smart contract, and be able to earn a fair share of the service fee revenue for actions coming through their marketplace. Now there are finally incentives to use universal smart contract that fairly rewards all marketplaces and unites listings and liquidity to make the experience better on all sites for the users. 👇

This massively lowers the entry barriers for building a marketplace on Cardano. Now, we can expect more niche or collection-specific marketplaces to emerge as they finally can make economical sense. Additionally, the adoption of Cardano NFTs for cross-chain marketplaces is now at the tips of their hands—they can now simply utilize this smart contract, instantly get access to all the listings and revenue.

To make the adoption even easier, we've developed an SDK & examples on how to interact with the smart contract to make the adoption even easier. If you're an building looking to build your own marketplace with JamOnBread smart contracts under the hood - start here, we also have a dedicated developer support channels on our Discord.

We're here not only to build innovative solutions but also to lower the entry barriers and make building for others easier.

It's time to make building on Cardano easier!


In summary, the innovative smart contract design tackles the challenges of marketplace creation on Cardano, promoting inclusivity and accessibility. With universal revenue-sharing and user-friendly SDKs, we're streamlining the process for builders, leading to a more diverse marketplace ecosystem. Our goal is to empower entrepreneurs and foster growth on Cardano by making building easier and more rewarding for all.