DS2API is a production-grade API proxy/gateway that translates DeepSeek's web chat API into OpenAI, Claude, Gemini, and Ollama-compatible endpoints. It provides a full-featured web UI for administration, account management, proxy configuration, and API testing. The system handles authentication (JWT, API keys, managed accounts), streaming responses with tool call detection, and multi-protocol request normalization. Architecturally, it is a Go backend with a React frontend (Vite + Tailwind). The backend is modular: protocol-specific handlers (OpenAI chat/responses, Claude messages, Gemini generate, Ollama chat) share a common prompt compatibility layer that normalizes requests to DeepSeek's internal format. A custom DeepSeek client manages authentication, PoW challenges, session lifecycle, and streaming. The SSE parsing infrastructure, tool call sieve, account pool, and config store are reusable components with extensive test coverage. Key data flows: incoming API requests are parsed and normalized to a unified prompt representation (role-tagged messages, tool descriptions, file references). The prompt is sent to DeepSeek's web chat API via a streaming or non-streaming completion runtime. Responses are parsed from SSE chunks, transformed (thinking extraction, tool call normalization, citation handling), and streamed back in the original protocol format. The system supports retry logic, account switching, and current input file injection for large contexts. External dependencies include DeepSeek's web chat API (reverse-engineered), Go standard library, chi router, utls for TLS fingerprinting, Node.js for Vercel streaming and WebUI build, and React/Vite for the frontend. The project is actively maintained with CI/CD pipelines, Docker images, and Vercel deployment support.
FreeAPI is an open-source API hub that provides free REST APIs for learning and demonstration purposes. The backend is a monolithic Express.js application with MongoDB, offering a range of endpoints: static public data (cats, dogs, quotes, etc.), kitchen-sink features (HTTP methods, status codes, cookies, redirects), and full-featured CRUD applications (ecommerce, social media, chat, todo) with authentication (JWT, OAuth via Google/GitHub), real-time chat via Socket.IO, file uploads, email notifications, and payment integration (Razorpay, PayPal). The codebase is well-structured with reusable utilities (asyncHandler, ApiError, pagination helpers), modular validators, and seeding scripts. It also includes multiple React/Vite frontend examples (ecommerce with Redux, chat with Socket.IO, todo app, status code quiz) that demonstrate best practices in consuming APIs. The project is clearly a learning resource and demo platform, not a production service.