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Creates a slabbed NFT from provably owned NFTs across multiple chains onto Polygon, factoring in numerous quality related attributes; imitating PSA from traditional trading cards


Created At

Road to Web3

Winner of


🏊 Polygon Pool Prize

Project Description

The project allows for existing, approved NFTs across well known blockchains to be graded and "slabbed" to be immortalised forever. Each existing NFT can only ever be minted once and the grade will depend on a range of factors, including number of transfers and amount of time held. This process is akin to traditional card grading and continuing with this project I'm planning to turn digital NFTs into physical cards that can be delivered.

How it's Made

The infrastructure has quite a lot of moving parts. At its core there is a Node express server that allows for newly minted NFT meta data and NFT images to be generated on their first request and then stored for subsequent calls. To calculate our NFT grade I use the Chainlink AnyAPI so that I can access information off the blockchain which proved vital. In this external query I get the existing NFT's transfer history, confirm it currently belongs to the owner and how long it has been held. This gives us a numeric value out of 100 which is then written against the blockchain with some other data. We connect across chain with Moralis and do a lot of our grading logic through their Web3API.

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