Is there any documentation of the api, so that someone can call it directly without going through the sdk?
We use gRPC on our workers. All API specs can be found here: https://github.com/hatchet-dev/hatchet/tree/main/api-contrac...
However, the SDKs are very tightly integrated with the runtime in each language, and we use gRPC on the workers which will make it more difficult to call the APIs directly.