Tushar Shrivastava (Backend-Associate Consultant L1 - Development)

A bonding curve is a mathematical curve that depicts how pricing and token supply are linked. This bonding curve states that a token's price grows as its supply increases. As numerous individuals become engaged with the initiative and continue to buy tokens, for instance, the cost of each subsequent buyer increases slightly, providing early investors with a chance to profit. If early buyers identify profitable businesses, they may eventually make money if they buy curve-bonded tokens early and then sell them. For more related to crypto exchange, visit our crypto exchange development services. 

Check this blog | Tokenization of RWA (Real-World Assets): A Comprehensive Guide

Bonding Curve Design: Key Considerations :

1. Token pricing can be best managed by using unique purchasing and selling curves.
2. Those who adopt first are often entitled to better benefits to promote early support.
3. Inspect for any price manipulation and deploy measures to protect the integrity of the token sale.
4. As the last price system, the bonding curve will ensure that tokens are valued equitably in line with supply and demand.
5. After a rapid initial development phase, your project will probably follow an S-curve growth pattern, resulting in a more stable maturity phase.
6. Aim for an enormous increase in the token's value over time. Pre-mining tokens should be carefully considered and backed by the project's specific requirements.

7. Make sure that token pricing is in line with the project's long-term value proposition and set reasonable fundraising targets.

    

How Bonding Curves Are Used?

1. Market Prediction 

Bonding curves are used by platforms such as Augur to generate dynamic markets for upcoming events. The price of each share varies according to market demand, and users can buy shares that reflect particular outcomes.

2. Crowdfunding and ICOs

Fundraising efforts can be streamlined by using bonding curves. For example, during initial coin offerings (ICOs), Bancor's protocol uses a bonding curve to control its token supply. This system ensures liquidity and reduces price volatility by enabling investors to buy tokens at a dynamic pricing.

An example of a bonding curve interaction:

• To enable users to mint or purchase a new token (such as the Bonding Curve Token, or BCT) with a designated reserve currency (let's say CWEB), a smart contract is developed.
  The price of BCT is algorithmically calculated in relation to its current circulating supply and shown in its reserve currency, CWEB.

   

• A smart contract will allow the user to purchase the new BCT token using the reserve currency. The sold CWEB is maintained in the smart contract as collateral and is not distributed to any individual or team.

   

• After the user completes their purchase, the price of the token will move along the bonding curve per the amount of supply the user has just created (probably increasing the price for future buyers).

   

• The decision to sell or burn a BCT token back to the curve can be made at any time. After their first purchase, the user will probably sell at a profit (less petrol and fees) if the price keeps rising. Following approval of their sale, the smart contract will return the bonded CWEB to the user.

   

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Bancor Formula 

The Bancor Formula calculates the price of a Continuous Token as it changes over time. The Reserve Ratio, which is determined as follows, is a constant used in the formula:

Reserve Token Balance / (Continuous Token Supply x Continuous Token Price) = Reserve Ratio

Implementation of Bancor Formula in Solidity :

        // SPDX-License-Identifier: UNLICENSED
        pragma solidity ^0.8.27;
        import "./SafeMath.sol";
        import "./Power.sol";

        contract BancorFormula is Power {
            using SafeMath for uint256;
            uint32 private constant MAX_RESERVE_RATIO = 1000000;
           
            function calculatePurchaseReturn(
            uint256 _supply,
            uint256 _reserveBalance,
            uint32 _reserveRatio,
            uint256 _depositAmount) public view returns (uint256)
            {
            // validate input
            require(_supply > 0 && _reserveBalance > 0 && _reserveRatio > 0 && _reserveRatio <= MAX_RESERVE_RATIO, "Invalid inputs.");
            // special case for 0 deposit amount
            if (_depositAmount == 0) {
                return 0;
            }
            // special case if the ratio = 100%
            if (_reserveRatio == MAX_RESERVE_RATIO) {
                return _supply.mul(_depositAmount).div(_reserveBalance);
            }
            uint256 result;
            uint8 precision;
            uint256 baseN = _depositAmount.add(_reserveBalance);
            (result, precision) = power(
                baseN, _reserveBalance, _reserveRatio, MAX_RESERVE_RATIO
            );
            uint256 newTokenSupply = _supply.mul(result) >> precision;
            return newTokenSupply.sub(_supply);
            }
           
            function calculateSaleReturn(
            uint256 _supply,
            uint256 _reserveBalance,
            uint32 _reserveRatio,
            uint256 _sellAmount) public view returns (uint256)
            {
            // validate input
            require(_supply > 0 && _reserveBalance > 0 && _reserveRatio > 0 && _reserveRatio <= MAX_RESERVE_RATIO && _sellAmount <= _supply, "Invalid inputs.");
            // special case for 0 sell amount
            if (_sellAmount == 0) {
                return 0;
            }
            // special case for selling the entire supply
            if (_sellAmount == _supply) {
                return _reserveBalance;
            }
            // special case if the ratio = 100%
            if (_reserveRatio == MAX_RESERVE_RATIO) {
                return _reserveBalance.mul(_sellAmount).div(_supply);
            }
            uint256 result;
            uint8 precision;
            uint256 baseD = _supply.sub(_sellAmount);
            (result, precision) = power(
                _supply, baseD, MAX_RESERVE_RATIO, _reserveRatio
            );
            uint256 oldBalance = _reserveBalance.mul(result);
            uint256 newBalance = _reserveBalance << precision;
            return oldBalance.sub(newBalance).div(result);
            }
        }

Implement Interface of IBondingCurve:

// SPDX-License-Identifier: UNLICENSED
        pragma solidity ^0.8.27;

        interface IBondingCurve {
           
            function getContinuousMintReward(uint _reserveTokenAmount) external view returns (uint);
            function getContinuousBurnRefund(uint _continuousTokenAmount) external view returns (uint);
        }

Implement Bancor Bonding Curve :

// SPDX-License-Identifier: UNLICENSED
        pragma solidity ^0.8.27;
        import "../math/BancorFormula.sol";
        import "../interface/IBondingCurve.sol";

        abstract contract BancorBondingCurve is IBondingCurve, BancorFormula {
            uint32 public reserveRatio;
            constructor(uint32 _reserveRatio) {
            reserveRatio = _reserveRatio;
            }
            function getContinuousMintReward(uint _reserveTokenAmount) public view returns (uint) {
            return calculatePurchaseReturn(continuousSupply(), reserveBalance(), reserveRatio, _reserveTokenAmount);
            }
            
            function getContinuousBurnRefund(uint _continuousTokenAmount) public view returns (uint) {
            return calculateSaleReturn(continuousSupply(), reserveBalance(), reserveRatio, _continuousTokenAmount);
            }
            // These functions are unimplemented in this contract, so mark the contract as abstract
            function continuousSupply() public view virtual returns (uint);  
            function reserveBalance() public view virtual returns (uint);
        }

Conclusion 

We highlighted key considerations for bonding curve design, including the importance of managing token pricing, preventing price manipulation, and aligning the token's value with the long-term goals of the project. By leveraging the Bancor Formula and its implementation in Solidity, we created a model that can adjust token prices dynamically based on supply and demand, while maintaining liquidity and reducing price volatility. 

At Oodles , we specialize in advanced blockchain solutions, including bonding curves for token sales and DeFi applications. 

Contact our blockchain developers today to bring your token project to life.

In the next 4-5 years, the cryptocurrency development will encounter extraordinary challenges that will transform familiar digital assets such as Bitcoin (BTC) and Ethereum (ETH) as we know them. The introduction of quantum computing jeopardizes the security of the current ECDSA (Elliptic Curve Digital Signature Algorithm) protocols, on which these assets rely. As quantum technology improves, cryptocurrencies will undoubtedly reach a tipping point, forcing people to adapt or be left exposed.

This imminent change is expected to result in a time of rapid transformation throughout the cryptocurrency sector. There will be numerous efforts to tweak or "fork" current blockchains using blockchain development services so that they are post-quantum secure. This transition will be difficult and disruptive for many projects as developers try to incorporate quantum-resistant algorithms to protect against potential flaws.

Quantum-Resistant Blockchain App Development Using Mochimo

In this changing context, a new sort of blockchain may emerge—one designed from the bottom up to handle both the threats posed by quantum computing and the existing scaling concerns confronting today's leading cryptocurrencies. Such a blockchain would be:

1. Post-Quantum Secure: Security methods designed to withstand quantum computing attacks.

2. Built on Evolved Technology:  With years of experience from previous cryptocurrency initiatives, this blockchain would have a polished and optimized codebase.

3. Highly Scalable: Designed to process substantially more transactions per second than Bitcoin or Ethereum, solving concerns such as blockchain bloat and transaction throughput limitations.

4 . Fast to Sync: A blockchain in which syncing a full node takes only minutes, hence boosting accessibility and lowering entry barriers for new users.

To solve the issues with current blockchain systems, Mochimo (MCM), a third-generation cryptocurrency and transaction network, was created from the ground up. Using post-quantum cryptography technologies, Mochimo, which was created from the ground up, combines elite features into a seamless ecosystem that is future-proof. It makes use of a unique proof-of-work mining technique, a novel consensus method, and a randomized peer-to-peer network. When combined, these components produce a distributed ledger that is trustless and improves the security and effectiveness of cryptocurrency transactions.

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The design of Mochimo addresses a variety of challenges:

As cryptocurrencies have developed, their broad usage has led to a number of difficulties. A lot of coins from the second generation try to address one or more of these problems. However, the Mochimo team has developed a thorough and progressive strategy by including a variety of cutting-edge design elements in bitcoin that successfully solve all of the following issues rather than putting answers into place piecemeal.

• The Threat of Quantum Computers.
• A Long-Term Solution for Network Scalability.
• Ensuring FIFO Transactions and No Transaction Queues.
• Transaction Throughput and Security.

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Notable Currency Statistics in Mochimo

Supply Maximum: 76,533,882
Coins that can be mined: 71,776,816 (93.8%)
Trigg's Algorithm-PoW is the mining algorithm.
Challenge Modification: Each Block
Goal Block Duration: 337.5 Seconds
Genesis Block: Network TX, June 25, 2018 Fee: fixed at.0000005 MCM
Initial incentive: 5.0 MCM per block Bonus Growth (through Block 373,760) Four Years:.00015 MCM
Block 373,760's maximum reward is 59.17 MCM per block. 

Reward Decrement:.000028488 (through Block 2,097,152 22 Years) MCM
Block 2,097,152 Final Reward: 5 MCM
Complete Mining Time frame: about 22 years
 

Premine Specifics:- 
 

Premine total: 6.34% (4.76M MCM)
Premine for Dev Team Compensation: 4.18% (3.2M MCM)
Other Premine: 2.16% (1.56M MCM) (run by the Mochimo Foundation)
Genesis Block: 23:40 UTC on June 25, 2018

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Several crucial actions must be taken to incorporate Mochimo's quantum-resistant features into your application:

1. Download and Install Mochimo Server:

  Mochimo Website: https://mochimo.org/
  Mochimo GitHub: https://github.com/mochimodev/mochimo.git
  
    
2. Set up the server and find the configuration files:

Locate the Mochimo configuration files after installation; these are often located in the installation directory.

3. Modify the configuration:

Use a text editor to open the primary configuration file, which is frequently called mochimo.conf. Set up parameters like data folders, network settings, and port numbers. Verify that the server is configured to listen on localhost, which is usually 127.0.0.1.

4. Launch the server for Mochimo:

Get a Command Prompt or Terminal open. Go to the directory where Mochimo is installed. Start the Server 

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Step-by-Step Integration of Mochimo Server with Your Express Application:

1. Ensure that the Mochimo server is operating locally and listening on the designated port, which is 2095 by default.
2. Install Node.js and install the required packages for your Express application.
3. Install Required Packages: npm install express body-parser axios net

The code is here:

const express = require('express');
const bodyParser = require("body-parser");
const net = require('net');
const axios = require('axios');
const app = express();
const port = 9090;
const MOCHIMO_NODE_URL = 'http://localhost:2095';
app.use(bodyParser.json());
// Function to check the Mochimo server status using a socket
const checkMochimoStatus = () => {
   return new Promise((resolve, reject) => {
       const client = new net.Socket();
       client.connect(2095, 'localhost', () => {
           console.log('Connected to Mochimo Server');
           client.write('Your command here\n'); // Replace with a valid command if necessary
       });
       client.on('data', (data) => {
           console.log('Received:', data.toString());
           resolve(data.toString());
           client.destroy();
       });
       client.on('error', (err) => {
           console.error('Socket error:', err);
           reject(err);
           client.destroy();
       });
       client.on('close', () => {
           console.log('Connection closed');
       });
       setTimeout(() => { Mochimo Website: 
           console.log('Connection timed out');
           client.destroy(); 
       }, 10000);
   });
};
// Endpoint to check Mochimo server status
app.get('/check-mochimo-status', async (req, res) => {
   try {
       const response = await checkMochimoStatus();
       console.log("Response:", response);
       res.status(200).json({
           message: 'Mochimo Server is running',
           data: response,
       });
   } catch (error) {
       res.status(500).json({
           message: 'Failed to connect to Mochimo Server',
           error: error.message,
       });
   }
});
// Endpoint to send a transaction to the Mochimo server
app.post('/send-transaction', async (req, res) => {
   const { sender, recipient, amount, privateKey } = req.body;
   try {
       const response = await axios.post(`${MOCHIMO_NODE_URL}/api/transactions/send`, {
           sender,
           recipient,
           amount,
           privateKey,
       });
       res.status(200).json({
           message: 'Transaction sent successfully',
           transaction: response.data,
       });
   } catch (error) {
       console.error('Error sending transaction:', error);
       res.status(500).json({ error: 'Failed to send transaction: ' + error.message });
   }
});
// Endpoint to check the balance of an address
app.get('/balance/:address', async (req, res) => {
   const { address } = req.params;
   try {
       const response = await axios.get(`${MOCHIMO_NODE_URL}/api/addresses/${address}`);
       res.status(200).json({
           address,
           balance: response.data.balance,
       });
   } catch (error) {
       console.error('Error fetching balance:', error);
       res.status(500).json({ error: 'Failed to fetch balance: ' + error.message });
   }
});
// Start the Express server
app.listen(port, () => {
   console.log(`Mochimo backend application listening at http://localhost:${port}`);
});

Conclusion

The impending development of quantum computing poses serious problems for the cryptocurrency market and compromises the safety of well-known assets like Ethereum and Bitcoin. Strong post-quantum solutions are becoming increasingly important as these technologies advance. Proactive efforts are being made to create a new generation of cryptocurrencies that are intrinsically immune to quantum attacks, as demonstrated by projects like Mochimo. To solve the shortcomings of existing systems and provide a safe and convenient environment for users, Mochimo intends to incorporate sophisticated encryption techniques, improved scalability, and effective transaction processing. To ensure the long-term viability and security of digital assets in a post-quantum world, the cryptocurrency industry will need to employ quantum-resistant technologies as it navigates this transition. If you are looking to build a blockchain-based application, connect with our skilled blockchain developers to get started. 

NFT Rental Marketplace Development using ERC 4907

For a predetermined period, NFT owners can lease their tokens to third parties via ERC 4907. This functionality allows different players or users to temporarily use the NFTs in various applications, such as virtual real estate or gaming.

The roles involved in this process include the Owner, who possesses the NFT; the User, who has the NFT in their wallet but is unable to sell or transfer it; and the "expires" function, which automatically ends usage without any further action required.

A controller or operator role is assigned to oversee a large number of NFTs. While they can perform certain usage operations, individuals in these roles are unable to approve or transfer the NFT, unlike the owner.

As an extension of ERC-721, the ERC 4907 standard introduces the dual roles of "owner" and "user" at the application layer. With an automatic "expires" mechanism that enforces the user's time-limited role, ERC 4907 simplifies NFT rentals. Thanks to this innovative feature, NFTs are automatically rentable; owners no longer need to manually revoke user privileges, saving time and avoiding additional on-chain transactions.

The main challenge arises in usage rights management, making it essential to establish a unified standard to facilitate collaboration across all applications.

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Real-world Applications and Collaborations

It's becoming more and more common in the world of digital assets for non-fungible tokens (NFTs) to use the new Ethereum token standard, ERC 4907. In order to facilitate the temporary transfer of usage rights while maintaining ownership, it creates a new "user role" that is distinct from the "owner role." This is advantageous for subscription or rental models.

In order to enable NFT rentals, Double Protocol has incorporated ERC 4907, allowing asset owners to lease without forfeiting ownership. This expands the utility of NFT and opens up new revenue streams. By including ERC 4907-based rental options, their relationship with Shardeum, a scalable smart contract platform, improves this strategy even further and fosters an NFT ecosystem that is more widely available.

These collaborations highlight the real-world applications and transformative potential of ERC 4907, leading to a more dynamic digital asset market. As these partnerships develop, they promise significant changes in the landscape of NFTs and digital ownership.

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ERC 4907 Use Cases

Gaming

Players can rent rare in-game items or characters temporarily, allowing for access to premium content without a full purchase.

Virtual Real Estate

Users can rent virtual plots of land or properties in metaverse platforms for specific events or time periods.

Art and Collectibles

Artists can rent their works for exhibitions or shows, allowing more people to experience the art without ownership.

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Renting NFTs is a reasonable approach

The blockchain used the actual world as a source for the concept of renting. Instead of paying money to use something that the other party has, one party wants it but cannot afford to own it or doesn't need it. People adore the thought of living off the returns from their assets, exactly like in the real world. Rentable NFTs' primary concept is that they are a passive revenue source.

What Advantages Does ERC 4907 Bring?

Market Liquidity

ERC 4907 will enhance NFT renting and enable related derivatives across various use cases, such as gaming, art, and music. As the Metaverse and Web3 expand,     more people will opt to rent NFTs instead of buying assets, increasing market liquidity over time.

Easy Third-party Integration

ERC 4907, which establishes a single standard, will enhance collaboration and assist Ethereum's cross-platform ecosystem. This standard improves communication between all parties engaged in utility NFT leases for gaming, the metaverse, and membership cards by simplifying integration and reducing development costs.

Moreover, third-party protocols employing ERC 4907 may oversee NFT usage rights without needing permission from the initial issuer. Others can swiftly do their own tasks when a project gives users this position. A PFP NFT, for instance, may be included in a platform that permits short-term rentals and simultaneously offers "rent-to-own" options via a mortgage platform without the original project's permission.

Backward Compatibility

By introducing an extended function set, the ERC 4907 standard can achieve full ERC-721 compatibility. Furthermore, there are a lot of parallels between the new functions provided in this standard and the current ERC-721 functionalities. This makes it possible for developers to embrace the new standard swiftly and simply. Future and current NFTs produced as standard ERC-721 can be wrapped to be compatible with ERC 4907 or upgraded to ERC 4907.

Also, Read | How to Create a Compressed NFT on Solana

Need of ERC 4907

Renting Out Assets

Owners can lease their digital assets while maintaining ownership according to ERC 4907, which permits NFTs to be rented out. For asset holders, this means additional revenue prospects.

Increased Digital Assets' Value

This standard increases the functionality of NFTs and encourages their wider use across a range of industries, including gaming and virtual real estate, by allowing them to be rented.

Innovative Uses

In the NFT space, the standard fosters innovation by creating opportunities for new applications including digital art exhibitions, virtual events, and game rentals.

Also, Check | A Step-by-Step Tutorial of Building a Cross Chain NFT Bridge

Things to Take Into Account When Implementing ERC 4907

1. In situations when the rental mechanism is not thoroughly monitored, users may take advantage of it. For example, they may rent an NFT for a very little time in order to swiftly transfer it without the owner's permission.

2. Legal concerns may arise from renting digital assets, particularly if the NFTs include copyrighted content or other intellectual property. Users might have to make sure local laws are followed.

Also, Discover | NFT-Based Loyalty Programs: Revamping Customer Engagement

Details of the ERC 4907 Interface:

// function setUser(uint256 tokenId, address user, uint64 expires) external
   Main Purpose: Assigns a user to an NFT along with an expiration time.
   Parameter:
                 tokenId: Unique Identifier of NFT
                 user: the address of new user who can Use NFT
                 exepires: duration until which the user can access the NFT    
   Access-Control : Usually callable from an authorised address or the NFT owner. This guarantees that user access can only be modified by authorised entities.
// function userOf(uint256 tokenId) external view returns (address);
Purpose: identifies the NFT's engaged user.
Parameters:
                  tokenId:Unique Identifier of NFT.
Returns: The user's address. It returns the zero address (address(0)) in the event that the user has expired or if no user is allocated.
 // function userExpires(uint256 tokenId) external view returns (uint256);
Purpose: retrieves the NFT user's expiration timestamp.
Parameters:
                tokenId:Unique Identifier of NFT.
Returns: The Unix timestamp indicating the expiration date of the user's access. There is no user when the value is 0.
// Event UpdateUser(uint256 indexed tokenId, address indexed user, uint64 expires);
    Purpose: Emitted whenever a user is assigned or updated for an NFT.
    Parameters:
                     tokenId: unique identifier of the NFT.
                     user: Address of the new User.
                     expires: The new expiration timestamp.
    Significance: Real-time tracking of user assignments is made possible by this event for both front-end apps and external services.
    

Also, Read | NFT Domains | Revolutionizing Ownership in the Digital Landscape

ERC 4907 Implementation

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;


// ERC721 Implementation
contract MyERC721Token {
struct Token {
address owner;
address approved;
}


// Mapping from token ID to token information
mapping(uint256 => Token) private _tokens;
// Mapping from owner to number of tokens
mapping(address => uint256) private _balances;
// Mapping from owner to operator approvals
mapping(address => mapping(address => bool)) private _operatorApprovals;


// Counter for token IDs
uint256 private _tokenIdCounter;


// Events
event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);
event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);
event ApprovalForAll(address indexed owner, address indexed operator, bool approved);


// Mint a new NFT
function mint(address to) public {
require(to != address(0), "Cannot mint to zero address");
uint256 tokenId = _tokenIdCounter++;
_tokens[tokenId] = Token(to, address(0));
_balances[to]++;
emit Transfer(address(0), to, tokenId);
}


// Get the balance of an owner
function balanceOf(address owner) external view returns (uint256) {
require(owner != address(0), "Owner address cannot be zero");
return _balances[owner];
}


// Get the owner of a specific token
function ownerOf(uint256 tokenId) public view returns (address) {
address owner = _tokens[tokenId].owner;
require(owner != address(0), "Token does not exist");
return owner;
}


// Approve another address to transfer the specified token
function approve(address to, uint256 tokenId) external {
address owner = ownerOf(tokenId);
require(msg.sender == owner, "Not the token owner");
_tokens[tokenId].approved = to;
emit Approval(owner, to, tokenId);
}


// Get the approved address for a specific token
function getApproved(uint256 tokenId) public view returns (address) {
require(_tokens[tokenId].owner != address(0), "Token does not exist");
return _tokens[tokenId].approved;
}


// Approve or revoke permission for an operator to manage all tokens
function setApprovalForAll(address operator, bool approved) external {
require(operator != msg.sender, "Cannot approve oneself");
_operatorApprovals[msg.sender][operator] = approved;
emit ApprovalForAll(msg.sender, operator, approved);
}


// Check if an operator is approved to manage all tokens of the owner
function isApprovedForAll(address owner, address operator) external view returns (bool) {
return _operatorApprovals[owner][operator];
}


// Transfer ownership of a token
function transferFrom(address from, address to, uint256 tokenId) external {
require(msg.sender == from || msg.sender == getApproved(tokenId) || _operatorApprovals[from][msg.sender], "Not authorized");
require(_tokens[tokenId].owner == from, "Incorrect owner");
require(to != address(0), "Cannot transfer to zero address");


// Call before transfer hook
_beforeTokenTransfer(from, to, tokenId);


// Transfer the token
_tokens[tokenId].owner = to;
_tokens[tokenId].approved = address(0);
_balances[from]--;
_balances[to]++;


emit Transfer(from, to, tokenId);
}


// Internal function to clear approval when transferring
function _clearApproval(uint256 tokenId) internal {
if (_tokens[tokenId].approved != address(0)) {
delete _tokens[tokenId].approved;
}
}


// Internal hook to be overridden
function _beforeTokenTransfer(address from, address to, uint256 tokenId) internal virtual {}
}


// Interface for ERC 4907
interface IERC4907 {
event UpdateUser(uint256 indexed tokenId, address indexed user, uint64 expires);
function setUser(uint256 tokenId, address user, uint64 expires) external;
function userOf(uint256 tokenId) external view returns (address);
function userExpires(uint256 tokenId) external view returns (uint256);
}


// ERC 4907 Implementation
contract ERC4907 is MyERC721Token, IERC4907 {
// Custom errors
error CanNotRentToZeroAddress();
error NotOwnerOrApproved();
error InvalidExpire();


struct TenantInfo {
address tenant;
uint64 expires;
}


mapping(uint256 => TenantInfo) internal _tenants;


constructor() {
// Minting initial tokens
for (uint256 i = 1; i <= 10; i++) {
mint(msg.sender); // Minting 10 NFTs
}
}


function setUser(uint256 tokenId, address tenant, uint64 expires) public override {
if (ownerOf(tokenId) != msg.sender && getApproved(tokenId) != msg.sender) {
revert NotOwnerOrApproved();
}
if (tenant == address(0)) {
revert CanNotRentToZeroAddress();
}
if (expires <= block.timestamp) {
revert InvalidExpire();
}


TenantInfo storage ref = _tenants[tokenId];
ref.tenant = tenant;
ref.expires = expires;


emit UpdateUser(tokenId, tenant, expires);
}


function userOf(uint256 tokenId) public view override returns (address) {
TenantInfo storage ref = _tenants[tokenId];
if (ref.expires >= block.timestamp) {
return ref.tenant;
} else {
return address(0);
}
}


function userExpires(uint256 tokenId) public view override returns (uint256) {
return _tenants[tokenId].expires;
}


// Override the transfer function to clear tenant info on transfer
function _beforeTokenTransfer(address from, address to, uint256 tokenId) internal override {
super._beforeTokenTransfer(from, to, tokenId);


TenantInfo storage ref = _tenants[tokenId];
if (from != to && ref.tenant != address(0)) {
delete _tenants[tokenId];
emit UpdateUser(tokenId, address(0), 0);
}
}
}

Conclusion

With the release of ERC 4907, which provides a flexible framework designed specifically for the growing NFT rental industry, non-fungible tokens (NFTs) have evolved tremendously. Its dual-role strategy not only makes rights allocation more clear but also lays the foundation for a range of partnerships and applications. This innovation comes at a perfect time, as it tackles the intricacy of the leasing space and keeps up with the exponential growth of digital assets.

ERC 4907 represents an evolution in the NFT space by introducing rental functionalities, and providing new opportunities for monetization and interaction with digital assets. It opens the door to innovative business models and use-cases across various industries, enhancing the utility of NFTs beyond mere ownership.

The NFT environment is about to change as ERC 4907 redefines digital asset leasing and develops popularity across several ecosystems. A future of innovation and fluidity in digital asset management is promised by the protocol, which also offers increased security, operational efficiency, and a multitude of opportunities. As a major protagonist in the story of digital innovation, ERC 4907 solidifies its position by setting new standards that not only predict future trends but also meet present needs. Need assistance with developing your NFT project, connect with our skilled blockchain and NFT developers to get started. 

References: 

https://github.com/tronprotocol/tips/blob/master/tip-4906.md

https://ethereum-magicians.org/t/eip-6884-delegatable-utility-tokens-derived-from-origin-nfts/13837/

https://github.com/ethereum/ERCs/blob/master/ERCS/erc-7507.md/

https://github.com/ethereum/web3.py/issues/1351

https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/token/ERC721/IERC721.sol

https://forum.openzeppelin.com/t/error-verifying-erc721-in-etherscan-file-import-callback-not-supported-with-github-imports/4198

https://soliditydeveloper.com/erc-1155

https://medium.com/coinmonks/erc-721-tokens-b83d7fc3e740

https://ethereum.stackexchange.com/questions/117365/executing-view-read-functions-on-gnosis-safe-with-raw-encoded-data/

https://www.kaleido.io/blockchain-blog/how-to-create-and-deploy-an-erc-721-token

https://github.com/OpenZeppelin/openzeppelin-contracts/issues/3659

https://hips.hedera.com/hip/hip-376