Solick

Problem Statement & Solution Problem: Users on Solana often lack SOL for transaction fees, face friction with key management for multi-sig workflows, and want simple ways to pay fees in stablecoins (e.g. USDC) or use accumulated credit instead of holding SOL.

Solution: Solick provides a backend that (1) gasless transactions via the x402 payment standard—users pay in USDC while the server pays SOL for gas; (2) a credit system so payments become reusable credit for future transactions; (3) Grid (Squads) wallet integration for programmatic multi-sig and balances; and (4) Lulo yield integration for yield products. The API is secure, documented (Swagger), and ready for production use.

Tools, Frameworks & Technologies Category Technologies Runtime & language Node.js (v18+), TypeScript Web framework Express.js Database & ORM PostgreSQL, Prisma API docs Swagger / OpenAPI Security Helmet, CORS, rate limiting, JWT, bcrypt, Zod validation Blockchain Solana (devnet/mainnet), x402 payment standard Integrations Squads Grid API (wallets), Lulo API (yield) Logging & monitoring Winston, health checks, optional Redis Testing Jest Technical Implementation Overview REST API: Express app with typed routes, validation (Zod), and structured error handling. Core domains: users, posts, Grid accounts, gasless/credit transactions, and yield. Gasless & credit: Fee payer signs and submits transactions; users pay in USDC (or use existing credit). Payments are stored as GaslessPayment; credit is tracked per user and consumed in FIFO order via SponsoredTransaction and gasless-credit.service. Grid: Server-side Grid SDK usage for initiating/completing account creation (OTP), fetching balances by email or wallet, and supporting gasless flows that depend on Grid wallets. Data layer: Prisma schema with User, Post, GaslessPayment, SponsoredTransaction; migrations and seeding via npm scripts. Security: Input validation, JWT auth, role-based access, rate limits, security headers, and CORS configured per environment. For deeper technical detail, see the in-repo guides (e.g. COMPLETE_GASLESS_CREDIT_GUIDE.md, API_DOCUMENTATION.md) and the Project Structure section below.

Features 🚀 Express.js with TypeScript 🗄️ Prisma ORM with PostgreSQL 📚 Swagger/OpenAPI documentation 🔒 Comprehensive Security (Helmet, CORS, Rate Limiting, Input Validation) 🛡️ Authentication & Authorization (JWT, bcrypt, Role-based access) 🚫 Attack Prevention (SQL Injection, XSS, CSRF protection) 📝 Structured logging with Winston 🧪 Testing setup with Jest 🔄 Database migrations and seeding 📊 Monitoring & Health Checks 💰 Gasless Transactions - Pay transaction fees in USDC instead of SOL (x402 standard) 🎁 Credit System - Build up credit from payments and use it for future transactions 🔐 Grid Wallet Integration - Full support for Squads Grid multi-signature wallets 📈 Yield Investment - Integration with Lulo API for yield farming operations

Built With

• typescript