# Welcome to FIRST 721 CLUB [CryptoKitties](https://www.cryptokitties.co/) is a blockchain game centered around breedable, collectible. The first CryptoKitties [Genesis #1](https://www.cryptokitties.co/kitty/1) was born on 2017-11-23. As of 2022-09-15, the total trade volume of CryptoKitties has reached around 71K ETH, with 750K kitties been traded, 2.01M kitties been born, and 134K holders. The [first ERC-721 draft](https://github.com/ethereum/EIPs/issues/721) was proposed by [Dieter Shirley](https://github.com/dete)( CTO of CryptoKitties team) on 2017-09-20 (09-20 has been recognized as International NFT Day). ERC-721 is the first ERC(Ethereum Request for Comment) for NFT(Non-Fungible Tokens). [KittyCore](https://etherscan.io/address/0x06012c8cf97bead5deae237070f9587f8e7a266d) contract was written with ERC-721 draft as a reference, so CryptoKitties is recognized as the world's first ERC-721 NFT project. Generation (Gen) is an important property of CryptoKittes. All kitties were directly or indirectly bred from Gen0 kitties. The max supply of Gen0 kitties is 50,000, limited by the KittyCore contract. So far, 38,015 Gen0 kitties have been minted, and the remaining Gen0 kitties will not be available for sale and will only be used for special events. Gen0 kitties are scarce, and are the cornerstone of the CryptoKitties world. FIRST 721 CLUB currently selects [Gen0](https://www.cryptokitties.co/search?include=sale\&search=gen:0) as a requirement to join the CLUB. Welcome to FIRST 721 CLUB! We're waiting for you in Discord: Let's build the CryptoKitties community together! **References**： * [https://www.cryptokitties.co](https://www.cryptokitties.co/) * * * * --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://www.first721.com/page/en/first-721-club.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.