Built-in durability: Introducing Workflow Development Kit

What this post added

Introduces the Workflow Development Kit (WDK), an open-source TypeScript framework that makes durability a language-level concept for async functions. WDK uses `use workflow` and `use step` directives to turn async functions into durable workflows that can pause for minutes or months, survive deployments and crashes, and resume deterministically. It compiles steps into isolated API Routes, records inputs/outputs for replayability, and supports pausing workflows with webhooks for external events. WDK is designed to run on any platform via 'Worlds', with a Vercel World using Framework-defined infrastructure and a reference Postgres World provided.