Anonymice: 100% On-Chain, Randomly Generated, Free NFTs

6 min readSep 16, 2021

The Anonymice have arrived.

You just stumbled on a rare gem.

An NFT project designed from the ground up with two purposes:

1. Show off what’s possible with NFTs on the blockchain.
2. Not a cash grab.

But first, let’s do the bullet points:

  • 10,000 unique mice
  • 100% on-chain (no IPFS, no API)
  • Randomly generated by the smart contract when you mint
  • Free to claim the first 2k
  • Each mouse can be staked to generate 1 x $CHEETH per day
  • 0 Royalties on secondary sales

Now some important links:

…and back to the full explanation

Anonymice is a 100% on-chain, generative, PFP NFT that is free to mint.

No centralization, no cash grab.

Every single mouse is free to mint. The first 2,000 are totally free (just pay the gas to mint) and the next 8,000 can only be minted through owning a mouse first, staking it to generate $CHEETH and then spending that $CHEETH to generate the remaining 8k mice.

What about secondary royalties on OpenSea??


How do the devs plan to make any money?

We will be minting our own mice along with everybody else. If our project is popular, those mice will be more valuable and we can sell them to generate a profit for ourselves.

We’ve been really fortunate to be early to NFTs and have made a lot of money creating/buying/selling them this year. For this project, we wanted to do something fun that showed off what’s possible with smart contracts.

Ok, back to the technical stuff.

Every once in a while an NFT project launches that does something totally new and innovative with the tech. We hope to have a place in that short list of innovative projects.

So, this is how it works and why we think our concept deserves that coveted “innovative” tag.

There are 10k eventual mice to be minted. But they aren’t all available yet.

The first 2,000 can be claimed by anyone, for free. We set a one mouse per transaction limit to try and increase the distribution. When initially marketing the project we tried to drop hints in a variety of areas to hopefully grab a diverse set of initially minters.

Once you have a mouse, that’s where the fun starts.


You might be familiar with staking from DeFi but now we want to show what’s possible by using staking with NFTs.

Our Staking Contract:

If you’re not familiar, here’s a quick primer:

You stake a mouse. This means locking it into a contract. This isn’t permanent or time locked, you can unstake any time you want.

When you stake a mouse, it won’t be in your wallet anymore. It’s in the contract doing hard work each day to generate you more $CHEETH.

As soon as you stake, it starts generating rewards. Our reward token is called $CHEETH and it’s generated at a rate of 1 $CHEETH per mouse per day. So if you stake 5 mice, 24hrs later you’ll be able to claim 5 $CHEETH. 48 hours later you’ll have 10 $CHEETH, and so on.

Due to gas limitations, you can only stake a maximum of 10 mice per wallet address.

You can claim rewards at any time but you have to pay a gas fee each time you claim. So it’s usually best to only claim when you are planning to spend the rewards. Your rewards are never lost, they’ll keep accruing until you unstake.

You can unstake your mouse at any time. This removes it from our CHEETH Staking Contract and puts it back into your wallet. The unstake will also claim all remaining rewards left on that mouse.

The $CHEETH generated by staking your mice is really important because it’s the only way to mint the rest of the anonymice! (and do future stuff in the project like breeding, mutating and evolving your mice)

Here’s the cost breakdown of the entire 10k anonymice collection:

#0–1999: free to mint
#2000–3999: 1 $CHEETH to mint 1 mouse
#4000–5999: 2 $CHEETH to mint 1 mouse
#6000–7999: 3 $CHEETH to mint 1 mouse
#8000-#9999: 4 $CHEETH to mint 1 mouse

We increase the required $CHEETH at each tier because more and more mice can be staked, so $CHEETH emissions will slowly increase.

Sacrificing (Burning)

You can Sacrifice (also called “burn”) your mouse at any time to immediately mint a new one. This doesn’t cost any $CHEETH but your sacrificed mouse is gone forever.


This is a huge subject with a variety of different opinions so please give us a chance to explain what we mean when we say the mice are “on-chain”:

Our mice are 100% on-chain.

No IPFS, no API, no website. Just a smart contract, twitter account and these Medium articles.

In 50 years, if our website (and opensea) are gone, as long as Ethereum still works, your mice will still exist.

To verify this, visit our Smart Contract and read the tokenUri of a minted mouse:

Find function 14. tokenURI, enter 0 and click Query.

You’ll see a huge bunch of text. This is base64 encoded. Copy the entire block of base64 encoded text and decode it here:

Now you’ll see something a little more readable. You’ll see the metadata and all traits. The image itself is also base64 encoded so copy the text inside the image trait and paste it into a base64 image decoder like this:

Now you’ll see an image of your mouse! Everything is on-chain and easily readable by OpenSea.


We didn’t want to just build a pre-created collection of 10k mice. But we still needed to have some control over the appearance of them. So we first created a bunch of different traits (base mouse, hat, eyes, etc) and then we created a very simple set of instructions that the contract follows to generate your mouse.

The traits for your mouse are determined when you mint it. And it’s totally random each time.

When you mint a mouse, our contract generates a random number and assigns it to your NFT. We check to make sure this number has never been minted before and then assign it. Once your number is assigned to your NFT, it can never be changed.

Are there any rare traits?

Yep! We built some rules into our generation process to make sure that some numbers came up less often than others. The final trait distribution will depend on you minting each mouse and generating a new combination each time.

Can someone hack the process to mint specific traits?

Theoretically, yes they could. Since the blockchain is transparent and immutable, someone could analyze exactly how we are generating the random numbers for your mouse and they could write a script that waits until they can generate the exact combo they want.

But (and this is an important but), they couldn’t do this very often, and if rare traits are minted more often, they aren’t rare anymore! And now what we intended to be common traits are suddenly the rare ones. So if rare traits ultimately determine the value of a mouse, you are economically disincentivized to generate a lot of them.

And since each mouse is generative and depends entirely on data from the previous block, we don’t have any idea what future mice look like. There’s literally no hidden metadata for anyone to find. It doesn’t exist until that mouse is minted.

And that’s it!

We also setup a discord channel to discuss the project but we have no plans to expand it beyond what you see. Once all 10k mice are minted we plan to hand over the Discord to the community.

Join us on Discord:

We tried to design this collection to be fun, entertaining and a good way to show a little extra of what’s possible with NFTs through our staking and burning mechanics.

The devs will only profit if the mice they mint go up in value, just like you. This is done to motivate everyone to use the contract to buy/sell. No one gets any unfair advantage or access to any extras.

If you love collecting NFTs, we built this project for you! It’s free and easy to join.

If you create NFTs, we hope our mechanics inspire you to create something even more innovative.

What’s next?

We’re working on a few new ideas like breeding, mutating and evolving your mice. All 100% on-chain of course. But let’s get the first 10k minted and see what happens from there…




On-chain, generative NFT. Free to claim with defi mechanics. We don't have a website, just a smart contract.