Function Effects
Function Effects are in-game logic tools, not a public REST API surface. They belong in Code & Custom UI and should be tested in the game where players will use them.
Choose the right layer
| Goal | Recommended tool |
|---|---|
| Build a player interaction without code | Interactive Studio |
| Combine supported values and conditions | Function Effect overview |
| Run supported custom behavior or interface logic | JavaScript Function overview |
| Automate room and asset workflows outside the game | MCP setup or this REST reference |
REST boundary
The supported REST routes can create, copy, update selected top-level metadata, read room snapshots, import snapshots, request asset upload destinations, and read build items.
They do not provide a typed public endpoint for creating or editing Function Effects. Do not attempt to construct function payloads from an old API guide and insert them into room data.
Safe workflow for an existing game
- Make the behavior work through the no-code or scripting surface first.
- Test it as a player from the intended spawn.
- If you must preserve it during an automation workflow, download a room-data backup.
- Change only the supported surrounding data you need.
- Import and retest in a disposable game.
Need a custom interface?
Use the supported JavaScript and displayHtml documentation rather than assuming that ordinary browser capabilities are available in the game runtime. Begin with Code & Custom UI.