Access Gate Middleware — Sub Protocol

Description

Express and Next.js middleware that checks NFT ownership or subscription status on-chain before granting API/page access. Supports ERC-721, ERC-1155, and custom subscription contract verification with caching.

Details

Category: middleware
Files: 12
Chains: Ethereum, Arbitrum, Base, Optimism, Polygon

TypeScript Express Next.js ethers.js Redis Ethereum Arbitrum Base Optimism Polygon

Express middleware for REST API gating
Next.js middleware for page/route gating
ERC-721 and ERC-1155 ownership verification
Custom subscription contract support
Redis-compatible caching layer (optional)
Rate limiting per wallet address
Configurable grace period for expired subs
TypeScript with full type definitions

access-gate-middleware.sol

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.24;

import "@openzeppelin/contracts/token/ERC20/IERC20.sol";

/// @title Access Gate Middleware
/// @notice Express/Next.js middleware checking NFT ownership for access.
contract AccessGateMiddleware {
    address public immutable owner;
    uint256 public constant VERSION = 1;

    event Initialized(address indexed deployer);

    constructor() {
        owner = msg.sender;
        emit Initialized(msg.sender);
    }

    // ... full implementation in purchased package
}