SocialFi Creator Tokens Development

Token Staking with NFT Rewards Development

Staking with NFT rewards is hybrid of two mechanics: liquidity lock (user locks tokens, gets yield) and NFT distribution as additional incentive. Simple implementation "stake X tokens, get NFT" works but quickly loses appeal. Interesting mechanics built on dynamic NFTs that evolve with staking.

Basic Staking Contract Architecture

Staking contract implements three things: lock tokens, calculate accumulated rewards, mint/upgrade NFT by milestones.

contract TokenStakingWithNFT {
    IERC20 public immutable stakingToken;
    IRewardNFT public immutable rewardNFT;
    
    struct StakeInfo {
        uint256 amount;
        uint256 stakedAt;
        uint256 rewardDebt;     // for correct reward calculation
        uint256 nftTokenId;     // 0 if NFT not yet issued
        uint8 nftTier;          // current NFT tier (0–4)
    }
    
    mapping(address => StakeInfo) public stakes;
    
    uint256 public accRewardPerShare;   // accumulated reward per share (scaled 1e12)
    uint256 public lastRewardBlock;
    uint256 public rewardPerBlock;
    uint256 public totalStaked;
    
    // Milestones for NFT upgrade (in staking days)
    uint256[] public nftTierThresholds = [7, 30, 90, 180, 365];
    
    function stake(uint256 amount) external nonReentrant {
        _updatePool();
        
        StakeInfo storage info = stakes[msg.sender];
        
        // Pay pending rewards before stake change
        if (info.amount > 0) {
            uint256 pending = info.amount * accRewardPerShare / 1e12 - info.rewardDebt;
            if (pending > 0) _distributeReward(msg.sender, pending);
        }
        
        stakingToken.safeTransferFrom(msg.sender, address(this), amount);
        info.amount += amount;
        
        if (info.stakedAt == 0) {
            info.stakedAt = block.timestamp;
            // Mint initial NFT (Tier 0) on first stake
            info.nftTokenId = rewardNFT.mint(msg.sender, 0);
        }
        
        totalStaked += amount;
        info.rewardDebt = info.amount * accRewardPerShare / 1e12;
        
        emit Staked(msg.sender, amount);
    }
    
    function checkAndUpgradeNFT() external {
        StakeInfo storage info = stakes[msg.sender];
        require(info.amount > 0, "Not staking");
        
        uint256 stakingDays = (block.timestamp - info.stakedAt) / 1 days;
        uint8 newTier = _calculateTier(stakingDays);
        
        if (newTier > info.nftTier) {
            info.nftTier = newTier;
            rewardNFT.upgrade(info.nftTokenId, newTier);
            emit NFTUpgraded(msg.sender, info.nftTokenId, newTier);
        }
    }
    
    function _calculateTier(uint256 days_) internal view returns (uint8) {
        for (uint8 i = uint8(nftTierThresholds.length); i > 0; i--) {
            if (days_ >= nftTierThresholds[i - 1]) return i;
        }
        return 0;
    }
}

Dynamic NFT via On-Chain Metadata

ERC-721 with dynamic tokenURI — NFT changes image and attributes on upgrade. Two approaches: off-chain metadata on IPFS (fast, but needs update on upgrade) and fully on-chain SVG (more gas, but fully decentralized).

contract RewardNFT is ERC721, Ownable {
    mapping(uint256 => uint8) public tokenTier;
    mapping(uint8 => string) public tierImageURI;  // IPFS CID for each tier
    
    address public stakingContract;
    
    function mint(address to, uint8 initialTier) external returns (uint256) {
        require(msg.sender == stakingContract, "Only staking contract");
        uint256 tokenId = ++_tokenCounter;
        _safeMint(to, tokenId);
        tokenTier[tokenId] = initialTier;
        return tokenId;
    }
    
    function upgrade(uint256 tokenId, uint8 newTier) external {
        require(msg.sender == stakingContract, "Only staking contract");
        require(newTier > tokenTier[tokenId], "Cannot downgrade");
        tokenTier[tokenId] = newTier;
        emit TierUpgraded(tokenId, newTier);
    }
    
    function tokenURI(uint256 tokenId) public view override returns (string memory) {
        require(_exists(tokenId), "Token does not exist");
        
        uint8 tier = tokenTier[tokenId];
        string memory imageURI = tierImageURI[tier];
        
        // Generate metadata on-the-fly
        return string(abi.encodePacked(
            'data:application/json;base64,',
            Base64.encode(bytes(abi.encodePacked(
                '{"name":"Staker NFT Tier ', Strings.toString(tier), '",',
                '"description":"Reward NFT for loyal stakers",',
                '"image":"', imageURI, '",',
                '"attributes":[{"trait_type":"Tier","value":', Strings.toString(tier), '},',
                '{"trait_type":"Tier Name","value":"', _tierName(tier), '"}]}'
            )))
        ));
    }
    
    function _tierName(uint8 tier) internal pure returns (string memory) {
        if (tier == 0) return "Bronze";
        if (tier == 1) return "Silver";
        if (tier == 2) return "Gold";
        if (tier == 3) return "Platinum";
        return "Diamond";
    }
}

Important nuance: soulbound or transferable

If NFT is transferable — problem arises: someone can buy Diamond tier NFT on secondary market without staking. If NFT should reflect staking, needs soulbound (ERC-5192) or address binding in staking contract.

// ERC-5192: minimal soulbound interface
function locked(uint256 tokenId) external view returns (bool) {
    return true;  // all tokens locked
}

function _beforeTokenTransfer(address from, address to, uint256 tokenId, uint256 batchSize)
    internal override {
    // Allow only mint (from == address(0)) and burn (to == address(0))
    require(from == address(0) || to == address(0), "Soulbound: non-transferable");
    super._beforeTokenTransfer(from, to, tokenId, batchSize);
}

Reward Mechanics: Tokens vs NFT Boost

NFT tier can provide not just visual upgrade, but boost to reward rate:

function _getUserMultiplier(address user) internal view returns (uint256) {
    uint8 tier = rewardNFT.tokenTier(stakes[user].nftTokenId);
    // basis points: 10000 = 1x, 20000 = 2x
    uint256[5] memory multipliers = [uint256(10000), 11000, 12500, 15000, 20000];
    return multipliers[tier];
}

function pendingReward(address user) public view returns (uint256) {
    StakeInfo storage info = stakes[user];
    uint256 acc = accRewardPerShare;
    
    if (block.number > lastRewardBlock && totalStaked > 0) {
        uint256 blocks = block.number - lastRewardBlock;
        acc += blocks * rewardPerBlock * 1e12 / totalStaked;
    }
    
    uint256 baseReward = info.amount * acc / 1e12 - info.rewardDebt;
    uint256 multiplier = _getUserMultiplier(user);
    return baseReward * multiplier / 10000;
}

Early Unstake Penalty and Lock Periods

Penalty mechanics incentivize long-term staking and protect against dump after NFT acquisition:

uint256 public constant MIN_LOCK_PERIOD = 7 days;
uint256 public constant PENALTY_RATE = 1000;  // 10% in basis points

function unstake(uint256 amount) external nonReentrant {
    StakeInfo storage info = stakes[msg.sender];
    require(info.amount >= amount, "Insufficient stake");
    
    _updatePool();
    
    uint256 pending = info.amount * accRewardPerShare / 1e12 - info.rewardDebt;
    if (pending > 0) _distributeReward(msg.sender, pending);
    
    uint256 actualAmount = amount;
    
    // Penalty on early exit
    if (block.timestamp < info.stakedAt + MIN_LOCK_PERIOD) {
        uint256 penalty = amount * PENALTY_RATE / 10000;
        actualAmount = amount - penalty;
        stakingToken.safeTransfer(penaltyCollector, penalty);
    }
    
    info.amount -= amount;
    totalStaked -= amount;
    stakingToken.safeTransfer(msg.sender, actualAmount);
    
    // If fully exited — lock or burn NFT
    if (info.amount == 0) {
        rewardNFT.lockOnUnstake(info.nftTokenId);
    }
    
    info.rewardDebt = info.amount * accRewardPerShare / 1e12;
}

Security

Two main attack vectors on staking:

Reentrancy: all state-changing functions making external calls must have nonReentrant. Especially stake, unstake, claim.

Overflow in reward calculation: accumulated accRewardPerShare can overflow uint256 with large block count or large rewardPerBlock. Check scaling. MasterChef V2 from SushiSwap — good reference implementation.

Contract mandatory for audit before launch — staking holds user funds permanently and is priority attack target.