No public API but you can explore what butlerd supports here:
- https://docs.itch.ovh/butlerd/master/#/?id=launch-client-request
- https://github.com/itchio/itch/blob/master/src/main/reactors/launch/perform-launch.ts
Note that this is an internal API. Although we likely aren’t changing it in the near future, we reserve the right to make changes without notice.