Crossplay for Unity (Editor)
The free in-Editor companion window (Window -> Crossplay): sign in, browse the live catalog + guides, ask Relay in-Editor, wire client options, hand installs to the Hub. Includes the 'Multiplayer Test' tab (launch 2-4 local clients from one checkout — cloned Editors or standalone copies, each pinned to a distinct instance id — with one-click start/stop of the local .NET server) and, whenever the content piece is installed, the 'Content Sync' tab (two-way sync of authored Game Content between the game server and Unity ScriptableObjects: typed SO classes generated per content type, version-guarded publish back — the server store is master). Editor-only tooling, no runtime code. A must for Core — auto-installed, cannot be unselected.
This piece exposes prefabs and MonoBehaviours rather than interfaces. Drop its panel prefab from
com.crossplay.editor into a scene — there is no API to implement.