Settel

Settel is a revolutionary cryptocurrency payment platform that transforms how businesses accept crypto payments and how customers pay with digital currencies. Unlike traditional payment processors that charge high fees and require complex business verifications, or existing crypto payment solutions that force users through confusing wallet popups and technical barriers, Settel introduces an email-first payment model that makes crypto transactions as simple as clicking a button. Merchants can embed a single payment button on their website without any technical expertise, configure their receiving wallet address and supported blockchain networks, and immediately start accepting payments. When customers click the button, they enter a simple crypto ID (like a username), receive a secure payment request via email, and approve the transaction on their trusted device - no wallet installation or browser injections required. The platform integrates with the Pyth Network for real-time price feeds, ensuring accurate USD-to-crypto conversions across multiple blockchain networks including Ethereum, Polygon, Arbitrum, Optimism, Base, and Avalanche. Built with Next.js 15, TypeScript, and MongoDB, Settel provides merchants with real-time dashboards, transaction analytics, and instant payouts while offering customers a familiar, secure payment experience that feels natural and trustworthy. The system eliminates the complexity of traditional crypto payments, removes the high fees of payment processors, and creates a bridge between mainstream e-commerce and decentralized finance, making cryptocurrency accessible to businesses and consumers who want the benefits of blockchain technology without the technical complexity.

Settel is built as a full-stack Next.js 15 application using the App Router architecture, combining server-side rendering with client-side interactivity to create a seamless payment experience. The frontend leverages React 19 with TypeScript for type safety, Tailwind CSS 4 for styling, and Shadcn UI components built on Radix primitives for accessibility. The backend uses MongoDB with Mongoose for flexible data modeling, Next.js API routes for serverless functions, and Server Actions for direct database mutations. Blockchain integration is handled through Wagmi 2.16.9 for React hooks, Viem 2.37.4 for low-level Ethereum interactions, and RainbowKit for wallet connections across 50+ wallets. The email-first payment flow uses Nodemailer with custom HTML templates and secure token generation, while real-time price accuracy is achieved through direct Pyth Network API integration with exponential price calculation handling and intelligent caching. Multi-chain support is implemented through dynamic chain configuration with automatic network detection, and the embeddable payment button uses inline CSS and Shadow DOM isolation to prevent conflicts with host websites. Security is enforced through Clerk authentication, custom rate limiting middleware, signature verification for blockchain transactions, and anti-phishing measures in email templates. Performance optimizations include React Query for efficient data fetching, optimistic updates for better UX, database compound indexes, and adaptive polling with exponential backoff for real-time transaction status updates. The entire system is designed to be framework-agnostic, with the payment button working on any website through automatic script injection and fallback to vanilla JavaScript for maximum compatibility.