Developers often encounter significant challenges when maintaining and supporting JavaScript libraries across various runtime environments such as Node.js, Deno, Bun, and edge platforms like Cloudflare Workers and Vercel Edge Functions. As APIs evolve, manually crafted SDKs can become outdated, leading to bugs and inefficiencies due to duplicated code. To address this, generating SDKs from API specifications like OpenAPI, AsyncAPI, and gRPC is recommended as it ensures alignment with the API, reduces errors, and scales efficiently across multiple languages. The best TypeScript SDKs exhibit broad runtime compatibility, zero dependencies, accurate type definitions, support for advanced protocols, built-in testing, and comprehensive documentation. This approach not only improves developer experience but also significantly reduces maintenance burdens. Fern, a company specializing in SDK generation, emphasizes these principles by offering a code generation pipeline that produces idiomatic, zero-dependency TypeScript SDKs and rigorously tests them in real-world scenarios.