I had the same situation as yours, and after a lot of researches and tries most of the tools (e.g. Typewriter) and libs (e.g. Nswag, Kiota), nothing can satify my very simple requirement (a very simple transformation from C# to TS).

In the end, I decided to implement the tool myself using the following libraries:

• Scriban: a template engine to generate the typescript file from a template with some input data
• Roslyn: a C# parser to extract the C# classes, methods, enums information to pass to the scriban template for rendering

Find more details in this post: https://kalcancode.wordpress.com/2025/06/02/how-to-build-a-c-to-typescript-generator-tools-and-ideas/