List collection on Singular

How to get your collection listed on Singular marketplace
The Singular marketplace is the most advanced NFT marketplace to date with support for ERC-5773, ERC-6059, ERC-6220, ERC-6381, and ERC-6454 in addition to the support for ERC-721, ERC-2981, and other standard NFT-powering ERCs.
To ensure the best results when the collection is displayed, we prepared a list of suggested extensions to implement:
  • Ownable or OwnableLock: Used for access control or for access control with the ability to lock the operation of the smart contract
  • RMRKImplementationBase: Used to provide the basic collection information like name, symbol, and collection metadata and information about token supply and minting. Additionally, it contains a secondary sale royalties configuration compatible with ERC-2981
  • RMRKTokenURIPerToken or RMRKTokenURIEnumerated: Used to provide token URI
In order to be eligible for your collection to be listed on the Singular marketplace, it MUST implement and contain the following:

Access control

We rely on the existence of the owner entity in order to verify the management operations done through the marketplace. This means the owner view function must be exposed in your collection.
As this is a common practice in all of the smart contracts implementing the Ownable pattern, you should be compatible using any version of it. We suggest you use the Ownable or OwnableLock from @rmrk-team/evm-contracts as it provides an additional management role compatible with the Singular marketplace called contributor. This allows you to appoint additional users to help you manage your collection via the marketplace.
If you are wondering why we are providing custom Ownable implementation, you can refer to the FAQ where we explain that.

Collection information

In order for the collection to be eligible to be presented in the Singular marketplace, it needs to have its name, symbol, maxSupply, and totalSupply exposed so that the marketplace can pick it up. Most of the metadata extensions contain it, but we suggest using any of the RMRK lego smart contracts from @rmrk-team/evm-contracts as they import the RMRKImplementationBase smart contract, which includes the name, symbol, maxSupply, and totalSupply values. Additionally, the RMRKImplementationBase contains the collectionMetadata providing metadata URI of the collection.

RMRK lego

As the Singular marketplace is specially equipped to present the next generation of Non-Fungible Tokens, it is crucial that your collection meets other advanced collections listed on Singular. If your collection was built without the powers of NFT 2.0, you can still wrap the tokens in order to power them up to reach the functionality of NFTs 2.0.
If you are still deciding on which RMRK lego to use and don't want to implement all of the base logic yourself, we encourage you to explore ready-to-use implementations that are documented in the Implementations section.

Additional notes

The @rmrk-team/evm-package offers many more powerful extensions to supercharge your collection. We invite you to explore them and build the best collection out there!


As there are more metadata-bearing resources when using NFTs 2.0, we prepared an overview of the expected metadata for each. You can refer to the structure of the metadata of collection, asset, and catalog part in the Metadata formatting section.