aep.d recommends using CEL as the filter language. However, the naming of the fields themselves are either snake_case in the case of protobuf, or camelCase in the case of JSON. This means that the filter syntax will be different, depending on whether you are using protobuf or JSON.

This might become problematic, especially if one is trying to pass the filter query directly from a JSON-based frontend to a proto-based backend. We probably need to decide on one, and provide some example or instructions on how the translation would work.

CC @hudlow