Core concepts

The Cometh NFT Marketplace API is a comprehensive solution designed to help developers build innovative applications and platforms leveraging NFTs and marketplace features. With support for ERC721 tokens, our API provides access to essential features necessary to build a marketplace, ensuring a seamless experience for developers.


Key API entities include:

  1. Project: A project is a set of collections on a specific EVM network. For each project, you have an API key and secret to authenticate the calls.

  2. Collections: A collection is a specific ERC721 contract that is registered on our system.

  3. Assets: An asset represents an ERC721 token with its associated metadata.

  4. Orders: Orders can be both purchase or sale orders. They are based on the 0x protocol.

  5. Transfers: Transfers occur when ownership of an NFT changes, either through a manual ERC721 transfer or upon order completion.

On-chain order operations

The simplest way of creating an order is to use the on-chain pre-sign operation on the 0x protocol. All orders, created either on-chain or off-chain, will be filled or canceled with on-chain operations.

User transactions generate event logs that are processed by our indexer. From the evolving on-chain 0x order data, we maintain our own enriched copy which is the one our API will provide.

Some of the most important fields from an order are the following ones:

  • Maker: The address that created the order

  • Direction: Whether this is a purchase or sale order

  • Taker: The address that filled the order (address 0 if the order is not filled)

  • Status: The current status of the order

The operations available for an order are the following:

  • pre-signing: This is equivalent to listing the order

  • canceling: This permanently cancels the order

  • filling: Allows a taker to fill an order, executing the final transfer of ERC20 tokens for the ERC721. The transfer's direction will follow the order's direction.

More information can be found about orders in Order flowand Preparing for transactions.

Last updated