Overview
The get_selection tool retrieves information about all instances currently selected in Roblox Studio’s Explorer window. This enables AI assistants and automation tools to operate on whatever the user has selected, providing a natural and intuitive workflow.
Use Cases
- Operate on objects the user has manually selected in Studio
- Build “act on selection” workflows for batch operations
- Validate selections before performing operations
- Guide users to select specific objects for processing
- Create context-aware tools that adapt to user selection
- Inspect properties of selected objects
Parameters
This tool takes no parameters.
Response Structure
Array of selected instances. Empty array if nothing is selected.
Full instance path in dot notation (e.g., “game.Workspace.Part”)
The name of the selected instance
The Roblox class type of the selected instance
Path to the parent instance
Example Response
{
"selection": [
{
"path": "game.Workspace.Level_01.Platform_1",
"name": "Platform_1",
"className": "Part",
"parent": "game.Workspace.Level_01"
},
{
"path": "game.Workspace.Level_01.Platform_2",
"name": "Platform_2",
"className": "Part",
"parent": "game.Workspace.Level_01"
}
]
}
Empty Selection Response
Usage Examples
Basic Selection Retrieval
// Get currently selected objects
const result = await mcpClient.callTool('get_selection', {});
if (result.selection.length === 0) {
console.log('No objects selected. Please select objects in Studio.');
} else {
console.log(`${result.selection.length} object(s) selected:`);
result.selection.forEach(obj => {
console.log(` - ${obj.name} (${obj.className})`);
});
}
Operate on Selected Objects
// Change properties of selected objects
const selection = await mcpClient.callTool('get_selection', {});
if (selection.selection.length === 0) {
throw new Error('Please select at least one object in Studio');
}
const paths = selection.selection.map(obj => obj.path);
// Make all selected parts red and transparent
await mcpClient.callTool('mass_set_property', {
paths: paths,
propertyName: 'BrickColor',
propertyValue: 'Really red'
});
await mcpClient.callTool('mass_set_property', {
paths: paths,
propertyName: 'Transparency',
propertyValue: 0.5
});
console.log(`Updated ${paths.length} objects`);
Validate Selection Type
// Ensure user selected only Parts
const selection = await mcpClient.callTool('get_selection', {});
const nonParts = selection.selection.filter(obj => obj.className !== 'Part');
if (nonParts.length > 0) {
console.log('Error: Please select only Part objects.');
console.log('Invalid selections:');
nonParts.forEach(obj => {
console.log(` - ${obj.name} (${obj.className})`);
});
} else {
console.log('All selected objects are Parts. Proceeding...');
// Continue with operation
}
Interactive Workflow
// Guide user through selection-based workflow
console.log('Step 1: Select the platforms you want to modify in Studio.');
console.log('Press Enter when ready...');
// Wait for user input (implementation depends on your environment)
await waitForUserInput();
const selection = await mcpClient.callTool('get_selection', {});
if (selection.selection.length === 0) {
console.log('No objects selected. Exiting.');
return;
}
console.log(`Processing ${selection.selection.length} platforms...`);
// Perform operations on selected objects
for (const obj of selection.selection) {
console.log(` Processing ${obj.name}...`);
// ... do work ...
}
console.log('Done!');
Inspect Selected Object Properties
// Get detailed info about selected objects
const selection = await mcpClient.callTool('get_selection', {});
for (const obj of selection.selection) {
console.log(`\n=== ${obj.name} ===`);
const props = await mcpClient.callTool('get_instance_properties', {
instancePath: obj.path
});
console.log(`Class: ${obj.className}`);
console.log(`Parent: ${obj.parent}`);
console.log('Properties:');
console.log(JSON.stringify(props, null, 2));
}
Group Selected Objects
// Group selected objects into a Model
const selection = await mcpClient.callTool('get_selection', {});
if (selection.selection.length < 2) {
console.log('Please select at least 2 objects to group');
} else {
const paths = selection.selection.map(obj => obj.path);
await mcpClient.callTool('group_objects', {
paths: paths,
groupType: 'Model',
groupName: 'GroupedObjects'
});
console.log(`Grouped ${paths.length} objects into 'GroupedObjects'`);
}
Clone Selected Objects
// Clone all selected objects
const selection = await mcpClient.callTool('get_selection', {});
for (const obj of selection.selection) {
await mcpClient.callTool('clone_object', {
instancePath: obj.path,
newName: `${obj.name}_Copy`
});
console.log(`Cloned ${obj.name}`);
}
console.log(`Created ${selection.selection.length} clones`);
Context-Aware Operations
// Perform different operations based on selection type
const selection = await mcpClient.callTool('get_selection', {});
for (const obj of selection.selection) {
if (obj.className === 'Part') {
// Make parts red
await mcpClient.callTool('set_property', {
instancePath: obj.path,
propertyName: 'BrickColor',
propertyValue: 'Really red'
});
} else if (obj.className === 'Script') {
// Add comment to scripts
const source = await mcpClient.callTool('get_script_source', {
instancePath: obj.path
});
await mcpClient.callTool('insert_script_lines', {
instancePath: obj.path,
afterLine: 0,
newContent: '-- Modified by automation'
});
}
console.log(`Processed ${obj.name}`);
}
Tips and Best Practices
Always check if selection.selection.length === 0 before operating on the selection. Provide clear feedback to users when nothing is selected.
Use get_selection to build interactive, user-guided workflows. This is more intuitive than asking users to type instance paths.
Selection state is captured at the moment the tool is called. If the user changes their selection after calling get_selection, you’ll need to call it again to get the updated selection.
If the user changes selection while your script is running operations, the selection data you have may become stale. Consider storing paths from the initial selection.
Validate selection types before performing operations. If you expect Parts but the user selected Scripts, catch this early and provide clear error messages.
Common Workflows
Selection → Validation → Operation
// 1. Get selection
const selection = await mcpClient.callTool('get_selection', {});
// 2. Validate
if (selection.selection.length === 0) {
return 'Please select objects first';
}
// 3. Operate
const paths = selection.selection.map(obj => obj.path);
await performBatchOperation(paths);
// Step 1: Select source objects
console.log('Select source objects and press Enter...');
await waitForInput();
const sources = await mcpClient.callTool('get_selection', {});
// Step 2: Select destination
console.log('Select destination folder and press Enter...');
await waitForInput();
const dest = await mcpClient.callTool('get_selection', {});
// Step 3: Clone sources to destination
for (const src of sources.selection) {
await mcpClient.callTool('clone_object', {
instancePath: src.path,
newParent: dest.selection[0].path
});
}
Common Issues
Issue: Selection returns empty array
- Ensure objects are actually selected in the Explorer window
- Verify the MCP bridge plugin is running and connected
- Try clicking objects again to refresh the selection
Issue: Selection doesn’t update
get_selection captures selection state at call time- Call the tool again to refresh selection data
- Selection is not “live” - it’s a snapshot
Issue: Can’t select certain objects
- Some objects (like Services) may not be selectable in Studio
- Locked objects might not appear in selection
- Hidden objects (via properties) can still be selected
