The problem Multichain NFT-AI-Companion solves

The tool is designed so that NFT holders can prove on other EVM chains (supported by Hashi) that they hold an NFT on mainnet (the specific implementation here is for the Based Ghouls NFT) and to mint a derivative of that NFT on any destination chain whose Hashi implementation stores the eth blockheader.

This infrastructure was a necessary unlock for the project we wanted to build (an AI powered NFT companion), as most people associate with a PFP that lives on Mainnet, yet it is expensive to bridge to another chain or launch this application ON mainnet (the one downside is that we cannot enforce continuous proofs of ownership under the current implementation).

Considering how greatly people identity with their NFTs, and their communities we thought it’d be interesting to allow them to verify their ownership on a cheaper chain, then converse with the NFT in a chat like interface.

Challenges we ran into

Our biggest challenge was getting the merkle tree verification to work. It was very difficult to find storage slots of ownership of specific NFTs among already deployed contracts (we tried Azuki and Pudgy for the majority of the weekend). In the end we went with @cometh’s existing implementation of the Based Ghoul contract storage slots finder and MPT verifier, though we still spend most of Saturday night debugging an updated blockheader, blocknumber, NFT owner and consequent proof.

At the end it was coffee and sheer will that won over type mismatches and incorrect inputs (and setting gwei 100x above average).