OpenAPI vs. TypeSpec: Which To Use?

TypeSpec and OpenAPI serve complementary roles in API development rather than competing solutions. OpenAPI remains the mature, widely-adopted standard for describing RESTful APIs with extensive tooling support, while TypeSpec offers a TypeScript-like language for defining APIs that can generate OpenAPI specifications and other formats. TypeSpec excels at schema reuse, multi-format output, and large-scale governance through its code-first approach, but OpenAPI is better for quick handwritten specs and non-technical stakeholder collaboration. The choice depends on specific project needs, with TypeSpec acting as a design-time abstraction layer that can enhance OpenAPI workflows.