Cryptotrunks

CryptoTrunks are generative NFTs that use oracles to create a specialized NFT trunk for each buyer, and users can mint an NFT tree that shows their crypto wallet’s environmental impact.The more CO₂ a collector has emitted, the bigger their trunk.Anyone can claim a free tree (except for gas fees). CryptoTrunks is working with Offsetra and Carbon.fyi to turn CryptoTrunks into a carbon-neutral or carbon-negative project. They plan to donate some of the proceeds from genesis trees to the Bull Run project, a reforestation program in Belize.

CryptoTrunks uses an oracle to look at a user's transaction history and calculates the total gas they have used. From this, an estimate is made of how many kilograms of CO₂ have been emitted and a random 100x100 pixel trunk is generated. A user can reroll as much as they like to see many different combinations available.

CryptoTrunks are available in two types, genesis and generative:

• Generative CryptoTrunks use oracles to look at a user's transaction history and build an NFT tree. There are 19500 generative trunks in total, with a variety of hidden elements and variations.
• Genesis CryptoTrunks are 1500 unique trunks that are set at a fixed price of 0.5 ETH. These are limited edition and contain assets that are not found in generative. They have been pre-generated and are selected for the buyer at random using chainlink VRF.

Ethereum uses a great deal of energy to run, which in turn means a lot of carbon is produced. CryptoTrunks uses an approach designed by Carbon.FYI to estimate the carbon cost of transactions initiated from a user's wallet. This works by multiplying the total gas spent from a user's address by an emissions factor based on the energy usage of the Ethereum network.

There are five tiers, based on how much gas a user has spent in their crypto wallet history. These are sapling, young, adult, elder and ancient; each size is an order of magnitude larger than the last.

To be sure that someone isn't taking all the generative trees for themselves, the price is increased for multiple growths. The goal is to have as many people as possible claim a free trunk, but a user can reroll until they get all the variations they desire. Larger trees carry a sense of prestige, so they are more expensive to grow. After a user's first purchase, additional trunks will cost more to mint. The cost per tier is the following:

Sapling - 0.05 eth

Young tree - 0.075 eth

Adult tree - 0.1 eth

Elder tree - 0.15 eth

Ancient - 0.25 eth

They then include a multiplier per mint:

2-5 - base price

6-20 - 1.5x

21-50 - 2x

51-100 - 2.5x

100+ - 3x

On May 23, 2021, two days after launch, CryptoTrunks temporarily paused generation of trunks, due to a sudden increase in popularity and increase in Ethereum's gas fees. CryptoTrunks wants to encourage as much free generative trunk minting as possible and cover the cost of the oracle transaction on their end, to be carbon negative. This means at higher gas prices, it becomes much more expensive for them to run the contract. Genesis exists partly as a way to subsidize the minting of free trunks. They resumed the project within hours as gas prices cooled, and now allow all paid generative minting as the prices are high enough to cover the transaction cost.