Pooled NFT

Pooled NFT is a protocol that enables fractionalizing NFTs into fungible ERC-20 tokens. This is useful in connecting NFT collections to DeFi. For example, adding liquidity to a uniswap market. ERC-20 tokens are fully backed 1:1 by specific NFT collections. There are no fees.

Overview

Pooled NFT consists of a collection of smart contracts for wrapping and unwrapping NFTs as ERC-20 tokens. The smart contracts work with the ERC-721 standard.

ERC721PoolFactory

A smart contract that is responsible for creating and registering new pools. Factories deploy their child smart contracts via CREATE2, which enables computing the pool smart contract address deterministically at the client side using only the seed as input. An example for logic that could be used to compute a CREATE2 address could be found here.

ERC721Pool

Responsible for managing the NFTs and the ERC-20 (Pooled NFT) tokens, and operates as follows:

• Any user can deposit NFTs to the pool in order to have an equivalent amount of the pool ERC-20 token minted and sent to their wallet address.
• Any user can pull out any NFT from the pool by trading in an equivalent amount of the pool ERC-20 token to be burnt by the pool.
• Any user can swap NFTs they hold in their wallet with an equivalent number of the same collection NFTs that are in the pool.

Development

Pre Requisites

You will need the following software on your machine:

• Git
• Node.Js
• Yarn

In addition, familiarity with Solidity, TypeScript and Hardhat is requisite.

Set Up

Install the dependencies:

$ yarn install

Create a .env file and follow the .env.example file to add the requisite environment variables. Now you can start making changes.

Deployment

To deploy and verify the factory smart contract, you would need to run the following line:

$ yarn hardhat deploy:contract:erc721-pool-factory --confirmations 5 --verify true

Integration

The following examples demonstrate how to interact with the factory smart contract to register new pools, or interact with individual pools to initiate deposits or withdrawals.

Examples

• How to enumerate through all active pools using the PooledNFT factory smart contract:

// To interact with the factory contract, you will need its abi.
// You can find that in the repository or on etherscan.
const pooledNftFactoryAbi = [...]
// The current factory pool address is: 0xb67dc4b5a296c3068e8eec16f02cdae4c9a255e5
const pooledNftFactory = new ethers.Contract(
    "0x...",
    pooledNftFactoryAbi,
    provider
)

const numberOfPools = await pooledNftFactory.allPoolsLength()
for (let i = 0; i < numberOfPools.toNumber(); i++) {
    const pool = await pooledNftFactory.allPools(i)

    // do something with pool here
}

• How to deposit an NFT into a pool:

// Add the ABI of the pool contract
const pooledNftPoolAbi = [...]
// Add the address of the pool contract
const poolAddress = "0x..."

// Add the ABI of the NFT contract
const nftAbi = [...]
// Add the address of the NFT contract
const nftAddress = "0x..."

const pooledNftPool = new ethers.Contract(
    poolAddress,
    pooledNftPoolAbi,
    signer
)

const nftContract = new ethers.Contract(nftAddress, nftAbi, signer)

// Add all token ids that you want to deposit into the pool
// You may also use only one token id in the array
const idsToDeposit = [1, 2, 3]

// Approving the pool to transfer the NFTs
for (const id of idsToDeposit) {
    console.log(id)
    const approveTx = await nftContract.approve(pooledNftPool.address, id)
    await approveTx.wait()
}

// Depositing the NFTs into the pool
const depositTx = await pooledNftPool.deposit(idsToDeposit)
await depositTx.wait()

• How to extract a specific NFT from a pool:

// Add the ABI of the pool contract
const pooledNftPoolAbi = [...]
// Add the address of the pool contract
const poolAddress = "0x..."

const pooledNftPool = new ethers.Contract(poolAddress, pooledNftPoolAbi, signer)

// Add all token ids that you want to extract from the pool
const idsToWithdraw = [1, 2, 3]

// Depositing the NFTs into the pool
const withdrawTx = await pooledNftPool.withdraw(idsToWithdraw)
await withdrawTx.wait()

License

GPLv3 © Hifi Labs.