MoonCats are procedurally generated pixel cats which are deterministically generated based on blockchain data.^[1][2]

How this works

Before you begin to rescue or adopt cats, you will need to connect to this site with Metamask, an extension for the Chrome browser. Install the plugin and create an account. You'll need to fund your account with some ether, which you can purchase directly through MetaMask. Rescuing a cat costs about $0.50 in gas. Metamask will prompt you whenever you need to spend ether - simply click "submit" to proceed or "reject" if you would rather not.^[1]

Rescuing Cats

After you have connected to this site with your Ethereum account, all you need to do is start your search for a MoonCat. You will have the option to decide how many CPU cores to devote to the task. We recommend using one less than the maximum, so you can find MoonCats quickly, but your computer won't hang. It takes anywhere from a few seconds to a few minutes to find a MoonCat. The process is very similar to how Ether is mined, so the timing depends on the power of your computer and the kiss of lady luck.

After you have found a MoonCat, you will be prompted to decide whether to rescue it or leave it on the moon. If you choose to rescue it, you will become its new owner and give it a home on the blockchain. You can choose to put your MoonCat up for adoption or give it to someone else. You can also choose to name your MoonCat if you please. MoonCats can only be named once though, so think carefully about names! Once you choose one, it will be permanent, even if it is adopted by someone else.

Offering Requesting, & Adopting Cats

If you do not want to search for a MoonCat, then you can go straight to the Adoption Center. In the Adoption Center you can view all of the rescued MoonCats and Genesis MoonCats. You can also adopt cats that are up for adoption, request a MoonCat from someone else, or give away MoonCats. All transactions are handled on the Ethereum blockchain in Ether, the currency of the moon.

Mining off the Chain

Instead of selling all of the MoonCats as the contract owner or giving all of the MoonCats away, we have given people the opportunity to find MoonCats by using their computers to generate a seed that hashes to an available and unique catId. This seed can then be submitted to the contract to rescue the corresponding MoonCat. The resulting MoonCat is initially owned by the Ethereum address that submitted it.

An off chain algorithm, the MD5 checksum of which is stored in the contract, parses the catId into its unique corresponding MoonCat image. This allows you to verify that your catId corresponds to your MoonCat image.

Additionally, the search seed is not known before the contract is activated. The search seed is generated based on the hash of the most recently mined block when a special activate function is called. This prevents the contract owners from using a known search seed to premine all of the MoonCats, and guarantees that the contract owners do not have a mining advantage over the rest of the community. Once the contract has been activated, it cannot be deactivated.

Procedural Generation

There are over 4 billion unique MoonCats possible. However, only 25,600 MoonCats can be added to the contract. This combination of mining with procedural generation allows for a unique experience that cannot be predicted before the contract is launched. Rescuers have the power to choose whether they want specific MoonCats to become part of the contract or not.

Irrevocable Naming

MoonCats can be named, but they can only be named once. Owners have to decide whether they want to name their MoonCat or keep it unnamed. We think that this creates an interesting dynamic. Owners can leave their mark by being the first and only person to name a MoonCat. However, it is our guess that unnamed MoonCats will fetch a premium in the Adoption Center.

Notable Sales

The platform since coming alive on a return to the NFT market saw their items (NFTs) experience a surge . One of the notable sales which occurred in the Secondary marketplace Opensea on the 27th of August ,2021 was the MoonCat #527: 0xff13000ca7 which sold out for 160 Ethereum which stands a whooping $216,635.20 on estimation.