TODO : Replacing signing scheme with metamask V4
TODO: Put data automaticallyh in decentralized storage (IPFS ?) https://www.arweave.org/
The work in progress of an universal NFT bridge.
A codebase for deploying and running opinionless EVM NFT bridges allowing the transfer of NFTs between them trough third party relays who are themselves free to implement their own trust mechanism.
Substrate modules, support for other signing methods than Ethereum Web3, and support for NFTs outside of the ERC-721 standard are planned.
The goal is that any bridge deployed on Mainnet/Rinkeby/Ropsten/Binance Chain/Moonbeam/Moonbase Alpha/Other EVM will be able to send NFTs to any parachain implementing the substrate module or an appropriate bridge smart contract. Once this is achieved, substrate module to substrate module communication between parachain trough the relay chain will also be implemented. Finally, more chains supporting NFTs (Wax, Flow) will be added to the migration ecosystem. Those might only be able to interact with the substrate module bridges, depending on the relevant technical challenges and limitations.
Decentralized blockchains allow you to truly own things trough your wallet without the need for third parties such as banks and other middlemen holding your assets for you, and NFTs are just the technical representation of unique assets on a blockchain. However, an NFT is always created in a single chain, and owners might want to move their unique assets to a different chain. How to transfer the NFT and the asset it represents from a token to another?
This is an open ended question with no correct answers, only compromises. Many solutions already exist, each with their own advantages and drawbacks, and more are poised to appear as time goes by. This could lead to issues:
- Many competing and incompatible projects is an overload of information for users and marketplaces. A lack of transparency and understanding will lead to a lack of trust.
- Many projects are focusing on the decentralized proof of state of the owner "burning" a token and minting it in an another chain. However, without the consent of the NFT publisher content, the minted token could be considered a counterfeit. Marketplaces might not be willing to take that risk and will refuse to sell the privately minted token as the original, meaning that essentially the migration would have failed as the new ownership is not recognized by anyone else.
- Separates two concepts : A Bridge is a smart contract serving as an escrow/messaging system for NFT migrations (think of it as an airport 🛄), Relays are the one trusted by both token publishers and token owners to actually perform the migration (think of them as airlines
✈️ ). - Can take tokens in escrow in order to mint a deed to them in an another chain.
- Can give back tokens in escrow when the deed to them is reclaimed in the bridge the deed was minted.
- Allow token publishers to veto their token being represented as deeds by third parties.
- Can take tokens in escrow in order for the original token publisher to mint them in an another chain.
- Can give back tokens in escrow when the token to them is migrated back in a fashion defined by the original token publisher.
- Allow token publishers to specify the only allowed migration destinations for a proper cross-chain NFT migration as well as hooking callbacks for it.
- Can provably show declared previous owner intent to migrate.
- Allow token publishers to designate relays.
- Allow users to chose a relay.
- Allow NFT owners to migrate tokens in a single operation : allowing a relay as the token operator.
This NFT bridge is based on the model described in "A protocol for NFT Migration", drafted as part of a Web3 Foundation grant: https://docs.google.com/document/d/1c5Uor2By5igFWXimipcKhsWjTAG8OWrl9bSVWTPsi6U/edit?usp=sharing
- NodeJS 12+ is supported
- Windows, Linux or macOS
This is the recommended installation method if you want to improve the Perpetual-Altruism-Ltd/myNFT-Bridge project.
Clone this repository and install the required npm dependencies:
git clone [email protected]:Perpetual-Altruism-Ltd/myNFT-Bridge.gitcd myNFT-Bridge/Codebase/Relay
yarncd myNFT-Bridge/Codebase/Bridge_Frontend
yarnThe backend hold a conf.json file here Codebase/Relay/conf.json.
You will need :
- A wallet private key with fund on each of the universes you want to interact
- An infura account with IPFS enabled (projectId and projectSecret)
- A bridge deployed on each universes you want to support with the wallet given before
- A IOU enabled ERC721 contract on each of the IOU destination universes, deployed with the wallet given before
Here a description of the configuration options :
{
"relayPrivateKey": "xxxxx", // Your relay wallet private key (must have been used to deploy IOU and bridge contracts)
"infuraIpfs": { // Your infura informations
"host": "ipfs.infura.io", // Default value
"port": 5001, // Default value
"protocol": "https", // Default value
"projectId": "205glgJgV59a6lg5A3w9qCWCS8k", // Your infura project id
"projectSecret": "78db432020396e4d0bf8963731a6b17a" // Your infura project secret
},
"port": 5000, // The port on which the http server of the relay will listen on
"universes": [ // A list of universes and worlds on which your relay will be operating
{
"name":"Ethereum Testnet Rinkeby", // The universe name
"rpc": "wss://rinkeby.infura.io/ws/v3/xxx", // The websocket enabled RPC on which your relay will be operating for this universe
"uniqueId": "0x07dac20e", // A unique id for your universe, will be used to communicate with the frontend (should be the same each side)
"bridgeAdress": "0x75Fcc7880A3C7FCaa0540c3307Cf00FC301fD242", // The bridge contract address
"explorer" : "https://rinkeby.etherscan.io/", // The explorer address to display transactions informations to users
"worlds": [ // A list of contract your relay will be using to emit IOU. One is usually enough
{
"address": "0xf2E02E4ee09428755C78658a636B31a289d772B6", // Contract address
"name": "MyContract", // Contract name
"tokenName": "TOKENNAME", // Token name
"owner": "0x00" // Owner of the contract
}
]
},
{
"name":"Ethereum Testnet Kovan",
"rpc": "wss://kovan.infura.io/ws/v3/d2b2cc5abf7e4632a6dc2d85d7d479de",
"chainID": 42,
"networkID": 42,
"uniqueId": "0xee0bec75",
"bridgeAdress": "0xF7c4fD79E2e121A69f1feD6224C332E9087706e5",
"explorer" : "https://kovan.etherscan.io/",
"worlds": [
{
"address": "0x3c1F63bDb0Ea3Fb6d5cf06195BFD7C48a29eDDBd",
"name": "MyContract",
"tokenName": "TOKENNAME",
"owner": "0x00"
}
]
}
]
}The frontend hold three configuration files :
Codebase/Bridge_Frontend/conf.json=> Configure the port the frontend server will be listening toCodebase/Bridge_Frontend/public/network_list.json=> Configure the networks available to this frontend and which migration route the token can migrate, as well as through which relaysCodebase/Bridge_Frontend/public/relay_list.json=> Configure the relay servers available to the frontend
{
"port": 8080 // Which port you want the frontend server to listen to
}{
"networks": [ // List of the networks
{
"name":"Ethereum Testnet Kovan", // Network name
"chainID": 42, // Chain id
"networkID": 42, // Network id
"uniqueId": "0xee0bec75", // Universe unique id
"bridgeAdress": "0xF7c4fD79E2e121A69f1feD6224C332E9087706e5", // Bridge address
"explorer" : "https://kovan.etherscan.io/", // Explorer address
"targetList": [
{
"relayIds": [1], // You can go from this(42) network
"networkId": 4 // To this network(4) through relay id 1
},
{
"relayIds": [1], // You can go from this(42) network
"networkId": 42 // To this network(42) through relay id 1
}
]
},
{
"name":"Ethereum Testnet Rinkeby",
"chainID": 4,
"networkID": 4,
"uniqueId": "0x07dac20e",
"bridgeAdress": "0x75Fcc7880A3C7FCaa0540c3307Cf00FC301fD242",
"explorer" : "https://rinkeby.etherscan.io/",
"targetList": [
{
"relayIds": [1],
"networkId": 4
},
{
"relayIds": [1],
"networkId": 42
}
]
}
]
}This project is a truffle project. There are multiple files in the contracts folder and you can select between:
MyNFTBridge.sol: This is the base bridge interface.Implementation/Implementation/ERC721.sol: This is the base ERC-721 token interface.
/Implementation/BridgeFeatures/ folder contains the different functions of the bridge.
The bridge implements the ERC-1538 proxy pattern in order to be upgradable:
ImplBridgeFunMigrateFromERC721.sol: This implements logic data of the arrival bridge (IOU minting / transfert / ...).ImplERC721TokenReceiver.sol: Handle the receipt of an NFT, the ERC721 smart contract calls this function on the recipient after atransfer.ImplMyNFTBridgeFunInit.sol: This implements logic data of a bridge initialization.ImplMyNFTBridgeFunMigrateToERC721.sol: This implements logic data of the departure bridge (migration intent / escrow and signature hash generation)
/Implementation/Proxification/ folder contains the different functions of the ERC-1538 proxy pattern for Bridge deployment. Get more infos here
/Implementation/Test/ folder contains an implementation of a token ERC-721 and a custom ERC-721 with premint functions (IOU)
Make sure that everything has been set up correctly:
$ truffle test
Update truffle-config.js with your credentials and network data:
networks : {
rinkeby: {
provider: () => new HDWalletProvider('yourprivatekey', `your_rpc_url`),
network_id: 4, // (eg : 4 = Rinkeby)
gas: 5500000, // Rinkeby has a lower block limit than mainnet
confirmations: 2, // # of confs to wait between deployments. (default: 0)
timeoutBlocks: 200, // # of blocks before a deployment times out (minimum/default: 50)
skipDryRun: true // Skip dry run before migrations? (default: false for public nets )
},
}
Deploy all contracts on this network (migration/bridge/erc721/iou):
$ truffle migrate rinkeby
If you only need to deploy a bridge, you can run:
$ truffle migrate --from 2 --to 2
The Web3 Foundation for supporting the creation of an NFT Migration protocol, which was the foundational work to build this NFT bridge, and to everyone who contributed to it.