CCXT is a cryptocurrency exchange trading library that provides a unified API for over 100 exchanges across 7 programming languages (TypeScript/JavaScript, Python, PHP, C#, Go, Java). The core is written in TypeScript from which all other language bindings are transpiled. It implements both REST and WebSocket APIs for market data, trading, and account management. The library normalizes exchange-specific data formats into a common schema, enabling cross-exchange arbitrage and analytics. Key architectural patterns include a base Exchange class with exchange-specific subclasses, a pro/ subdirectory for WebSocket-enabled exchanges, static_dependencies/ for vendored third-party code (ethers, starknet, bip39, etc.), and an extensive test suite with both static and live tests. The repository includes a playground (Next.js web IDE), CLI tool, documentation site (Fumadocs), CI/CD for all languages, and Docker development environment.