Onchain NFTs

Smart contracts for testing the compatibility of various wallets, portfolio managers and marketplaces with on-chain NFTs. In particular, this checks for ERC721 tokenURI() functions returning data URIs wherein all the metadata is stored on-chain, including the image data.

The metadata looks something like:

{
  "name": "Onchain #1",
  "description": "image prop - PNG data URI (big - 4286 bytes)",
  "attributes": [
    {
      "display_type": "date",
      "trait_type": "When",
      "value": "2024-09-09"
    }
  ],
  "image": "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAlgAAAJYCAIAAAAxBA+LAAAK2UlEQVR4nOzXvasQ1B/H8d8VxeHX0D... (3802 bytes total)"
}

For preliminary findings, see:

Example gas costs:

Calling setTokenURI() with JSON metadata containing 3802 byte PNG image: 0.074858856538066125 ETH (497077 gas * 150.598109625 gwei)

On-chain addresses

Polygon: 0xB4D3973637369692981C7C40f7a733a04b2D0E9c
- See the NFTs: https://polygon.nftscan.com/0xB4D3973637369692981C7C40f7a733a04b2D0E9c

Developer guide

Install pre-requisites:

Foundry
Bun

Then run:

$ bun i
$ bun prepare

To compile the contracts:

$ bun compile

To run a local devnet:

$ bun devnet

Deployment - local

To deploy contracts:

$ bun local:dep

To set values (substitute the correct CONTRACT_ADDRESS value):

$ CONTRACT_ADDRESS="0x.." bun local:set

Deployment - public network

To deploy contracts:

$ export PRIVATE_KEY="0x..."
$ export RPC_URL="http://..."
$ export CHAIN_ID="..."
$ bun public:dep

To set values (substitute the correct CONTRACT_ADDRESS value):

$ CONTRACT_ADDRESS="0x.." bun public:set

Debugging

Useful tools for debugging NFT metadata and testing images:

https://viewer.etovass.xyz/ (github: https://github.com/etovass/svg-nft-tutorials/tree/main/nextjs-tooling/nft-viewer)
https://polygon-nfts.com/ - view NFTs on polygon by contract address, etc.
https://nftscan.com/ - multi-chain NFT viewer

License

GPLv3 - see LICENSE.md

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/.