I tried it out directly in a project and it seemed good, so I published it to npm.
When implementing a repository/API client, you don't have to create a bunch of interfaces or type guards, and since you no longer need to do βasβ casting, errors are reduced as well. In fact, the amount of implementation code has decreased significantly.
If you're interested, take a look! It's zero dependency and really easy to use.

GitHub
GitHub - asheswook/valdex: Intuitive runtime type validation with TypeScript type inference
Intuitive runtime type validation with TypeScript type inference - asheswook/valdex

