Currently I'd vote for keeping it typed to JSON
Otherwise, some food for thought:
- "It's just JSON, stupid" theme gets pushed hard by atproto
- how opaque is this type?
- does this type have meaning outside atproto?
- how well formed and stable is this type?
Along those lines…
Atproto records can be encoded a few different ways - JSON, DRISL.
I would want a mime type to give me some hint as to the current encoding.