Overview
The Summer Engine MCP server exposes 23 tools in three categories: Scene (10), Debug (9), and Project (4). All tools require the engine to be running with a project open. If the engine isn’t running, tools return a clear error message.
Critical: Value formats. Properties like position, rotation_degrees, and mesh use engine string syntax, not raw JSON objects. See Value Formats below.
When setting properties via summer_set_prop or summer_set_resource_property, use these formats:
| Type | Format | Example |
|---|
| Vector3 | "Vector3(x, y, z)" | "Vector3(0, 10, 0)" |
| Vector2 | "Vector2(x, y)" | "Vector2(100, 200)" |
| Color | "Color(r, g, b, a)" RGBA 0.0 to 1.0 | "Color(1, 0.5, 0, 1)" |
| Transform3D | "Transform3D(...)" basis + origin | "Transform3D(1,0,0, 0,1,0, 0,0,1, 0,5,0)" |
| Resource | Class name, auto-instantiated | "BoxMesh", "SphereMesh", "StandardMaterial3D" |
| Number | Native JSON | 1.5, 42 |
| Boolean | Native JSON | true, false |
| String | Native JSON | "hello" |
Wrong: "position": {x: 0, y: 10, z: 0} stays Dictionary, fails
Right: "position": "Vector3(0, 10, 0)" parses to Vector3
summer_add_node
Add a new node to the scene tree.
| Parameter | Type | Required | Description |
|---|
parent | string | Yes | Parent path, e.g. ./World or ./World/Enemies |
type | string | Yes | Node type, e.g. MeshInstance3D, CharacterBody3D |
name | string | Yes | Name for the new node |
summer_add_node(parent="./", type="DirectionalLight3D", name="Sun")
summer_set_prop
Set a property on a node. Primary way to configure nodes after adding them.
| Parameter | Type | Required | Description |
|---|
path | string | Yes | Node path, e.g. ./World/Player |
key | string | Yes | Property name, e.g. position, mesh, visible |
value | string | number | boolean | Yes | Value in engine string format for complex types |
position, rotation_degrees, scale, visible, mesh, shadow_enabled, light_energy, fov.
Example: summer_set_prop(path="./World/Player", key="position", value="Vector3(0, 1, 0)")
summer_set_resource_property
Set a nested property on a resource attached to a node (e.g., shape size, material color).
| Parameter | Type | Required | Description |
|---|
nodePath | string | Yes | Node path |
resourceProperty | string | Yes | Resource property on node, e.g. shape, mesh, material_override |
subProperty | string | Yes | Property on the resource, e.g. size, radius, albedo_color |
value | string | number | boolean | Yes | Value in engine string format |
summer_set_resource_property(nodePath="./Player/CollisionShape3D", resourceProperty="shape", subProperty="size", value="Vector3(1, 2, 1)")
summer_remove_node
Remove a node from the scene tree. All children are removed. Cannot remove root. Supports undo.
| Parameter | Type | Required | Description |
|---|
path | string | Yes | Node path to remove |
summer_save_scene
Save the current scene to disk. Call after making changes to persist them.
| Parameter | Type | Required | Description |
|---|
path | string | No | Save-as path for creating a new scene file, e.g. res://levels/level2.tscn |
summer_open_scene
Open a scene file in the editor. Use to switch between scenes.
| Parameter | Type | Required | Description |
|---|
path | string | Yes | Scene path, e.g. res://main.tscn |
summer_instantiate_scene
Add an existing scene or 3D model as a child node. Use for .tscn prefabs or .glb/.gltf models.
| Parameter | Type | Required | Description |
|---|
parent | string | Yes | Parent node path |
scene | string | Yes | Scene/model path, e.g. res://player.tscn or res://models/tree.glb |
name | string | No | Override the instance name |
summer_connect_signal
Connect a signal between two nodes. The receiver must have a script with the specified method.
| Parameter | Type | Required | Description |
|---|
emitter | string | Yes | Node that fires the signal |
signal | string | Yes | Signal name, e.g. body_entered, pressed, timeout |
receiver | string | Yes | Node with the handler script |
method | string | Yes | Method name in receiver’s script |
body_entered, body_exited, pressed, timeout, area_entered, input_event.
summer_select_node
Select a node in the editor’s scene tree and show it in the inspector.
| Parameter | Type | Required | Description |
|---|
nodePath | string | Yes | Node path to select |
scenePath | string | No | Open this scene first, then select the node |
summer_replace_node
Replace a node with a different type or scene, preserving position and children.
| Parameter | Type | Required | Description |
|---|
path | string | Yes | Node path to replace |
type | string | No | New node type, e.g. RigidBody3D |
scene | string | No | Scene to replace with, e.g. res://enemies/boss.tscn |
summer_get_diagnostics
Quick overview of errors and warnings from the editor console and runtime debugger. Call this first before diving into console or debugger details.
Workflow: summer_get_diagnostics → if errors, use summer_get_console or summer_get_debugger_errors → fix → summer_get_diagnostics again to verify.
summer_get_console
Read recent messages from the editor’s Output panel. Use after diagnostics indicate console issues.
| Parameter | Type | Required | Description |
|---|
max_lines | number | No | Max lines to return (default 100) |
filter | string | No | Only return lines containing this string |
type | enum | No | Filter by: error, warning, std, editor |
summer_clear_console
Clear the editor’s Output panel. Useful before running the game for a clean slate.
summer_get_debugger_errors
Read runtime errors and warnings from the debugger (null refs, missing nodes, physics errors). Different from console. These occur while the game is running.
| Parameter | Type | Required | Description |
|---|
max_errors | number | No | Max errors to return (default 50) |
include_stack | boolean | No | Include stack traces |
summer_play
Start running the game in the engine. Use summer_game_snapshot to see what the player sees.
| Parameter | Type | Required | Description |
|---|
scene | string | No | Scene to run instead of main scene |
summer_stop
Stop the running game. Call before making scene changes. Some operations require the game to be stopped.
summer_is_running
Check if the game is currently running. Returns the active scene path if running.
summer_viewport_snapshot
Capture a screenshot of the editor’s 3D/2D viewport (editor camera, not game camera).
summer_game_snapshot
Capture a screenshot of the running game (player’s view). Call summer_play first. Returns base64 JPEG.
summer_project_setting
Set a project setting in project.godot.
| Parameter | Type | Required | Description |
|---|
key | string | Yes | Setting key path, e.g. application/config/name |
value | string | number | boolean | Yes | Setting value |
application/config/name, application/run/main_scene, display/window/size/viewport_width, physics/3d/default_gravity.
Set up input controls. Creates the action if it doesn’t exist, then binds events.
| Parameter | Type | Required | Description |
|---|
name | string | Yes | Action name, e.g. jump, move_forward |
events | array | Yes | Array of input event objects |
{ type: "key", key: "W" } or { type: "mouse_button", button: 1 } (1=left, 2=right, 3=middle).
summer_get_scene_tree
Get the full scene tree structure of the currently open scene. Returns all nodes with types, paths, and children. Use to understand the scene before making changes.
summer_import_from_url
Download a file from a URL and import it into the project. Triggers the engine’s full import pipeline. Use for .glb, .gltf, .obj, .png, .ogg, etc.
| Parameter | Type | Required | Description |
|---|
url | string | Yes | HTTP(S) URL to download from |
path | string | No | Target path in project. Auto-inferred from URL if omitted. |
summer_import_from_url_batch
Download multiple files from URLs in one operation. Single filesystem scan after all downloads. Faster than importing one at a time.
| Parameter | Type | Required | Description |
|---|
imports | array | Yes | Array of {url, path} objects |
Next Steps
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