Build a scene

The canonical build loop. You prompt in plain language; the assistant makes the editor calls and hands you the honest verdicts.

1. Scaffold

You: "Scaffold a main scene."

The assistant enables scene editing and creates a root scene. The root must be a built-in node type (e.g. Node2D) — a custom class_name is refused, because the editor can't instantiate script classes. To root a scene on a custom class, have the assistant create it with the base built-in type, then attach the script to the root.

2. Compose the tree

You: "Add a Player with a visible Body shape."

The assistant adds the nodes and sets their properties — node types, names, and values — all in your live scene. For several independent operations, ask it to batch them: many commands run in a single editor round-trip (the editor drains each in about a frame), which is far faster than one call per node.

3. Attach behavior

You: "Give the Player a movement script."

Script writes flush straight to disk (no scene save needed), so the assistant writes the script, attaches it, and the behavior is live in your editor immediately. Scene edits, by contrast, stay in the editor's memory until the scene is saved (step 5).

4. Physics

You: "Give the Player collision so it stands on floors."

The assistant sets the collision shape, body, and layers. Godot types arrive as plain JSON — a Vector2 size is {"x": 32, "y": 48} — and it dimension-checks the shape against the body up front: a 2D shape on a 3D body is refused with a naming hint, instead of silently shipping collisionless levels.

5. Verify, then save

You: "Check the script parses, then save the scene."

A clean parse is necessary but not sufficient — runtime API misuse only shows up when the game actually runs, so ask for a headless run too (see Verify your work). Then save.

Reading the persistence verdicts

Every mutation result carries a persistence verdict — whether the save will really keep the change:

• persisted: true → the save keeps it.
• persisted: false, reason: instanced_child_not_editable → the target is inside an instanced scene. Fix: ask the assistant to enable Editable Children on that scene (then re-apply), or to target a node the scene owns.
• persisted: false, reason: node_not_owned → the node has no owner (e.g. added by a @tool script); re-create it through the tools so the owner lands.
• Batch results: read persistence[] per target, and undoable.

Groups & signals

You: "Put the Player in the player group and connect the Enemy's died signal."

Both are undoable, and a signal connection that already exists reports already_connected instead of failing on the duplicate.

Undo

Ask the assistant to undo and it steps back the last editor action. Large batches above 20 nodes bypass the undo stack (the result says undoable: false) — plan those.

Next: Play-test & debug, or Verify your work.