PICO MCP Extensions

PICO XR feature construction APIs for Unity MCP agents. Idempotent, non-destructive, ambiguity-aware.

Overview

This Unity package exposes PICO XR building blocks as MCP (Model Context Protocol) tools, enabling AI agents (e.g. Unity AI Assistant) to programmatically configure XR scenes for PICO devices.

Package name: com.bytedance.pico.mcp-extensions
Version: 0.0.2
Unity: 2022.3+
Author: ByteDance PICO

Requirements

Dependency	Minimum Version
com.unity.xr.core-utils	2.3.0
com.unity.xr.interaction.toolkit	3.0.0
com.unity.inputsystem	1.7.0
Unity AI Assistant (Unity.AI.MCP.Editor)	2.x
com.bytedance.pico.xr	(project-installed)

Features

Four XR building blocks, each with Enable / Disable / Status semantics:

Block	Description
VST	Video See-Through (passthrough) - configures camera for transparent background and adds PXR_CameraEffectBlock
Controller	Mounts PICO controller visual models on Left/Right hand anchors
Locomotion	Enables XRI locomotion subtree with fine-grained presets (Move, Turn, Teleportation, GrabMove, Climb, Gravity, Jump)
Spatial Mesh	Configures PXR_SpatialMeshManager with auto-detected MeshPrefab (depends on VST)

Additionally, a Package tool manages Unity packages and samples (install / remove / update / import samples).

Architecture

Editor/
  PXR_MCP_Common.cs        # Shared helpers: XR Origin lifecycle, module visibility
  PXR_MCP_Features.cs      # Building block implementations (VST, Controller, Locomotion, SpatialMesh)
  PXR_MCP_PackageOps.cs    # Package Manager operations (add, remove, samples)
  Tools/
    PXR_MCP_Tools.cs       # MCP tool surface ([McpTool] entry points)
    PXR_MCP_Result.cs      # Uniform result envelope for LLM consumption

Layer 1 (Editor): Plain C# static methods + Unity MenuItems for manual validation.
Layer 2 (Tools): [McpTool]-annotated methods that wrap Layer 1 and return PXR_MCP_Result envelopes.

MCP Tools

Tool	Actions	Description
pico_xr_vst	Enable, Disable, Status	Manage Video See-Through
pico_xr_controller	Enable, Disable, Status	Manage PICO controller models
pico_xr_locomotion	Enable, Disable, Configure, Status	Manage locomotion with preset flags
pico_xr_spatial_mesh	Enable, Disable, Status	Manage spatial mesh (requires VST)
pico_xr_package	List, Info, Add, Remove, Update, ListSamples, ImportSample	Unity Package Manager operations
pico_xr_status	(none)	Aggregate snapshot of all blocks

Design Principles

• Idempotent: Re-running any operation with the same arguments is a safe no-op.
• Non-destructive: Never destroys or deactivates foreign (non-agent-owned) XR Origins.
• Module isolation: Enabling one block does not implicitly enable unrelated modules. Initial-create hides Controller and Locomotion so VST stays clean.
• No hardcoded versions: XRI paths and types are resolved dynamically via PackageInfo and reflection.
• Undo-safe: All scene modifications go through Unity's Undo system.

Installation

Add this package to your Unity project via the Package Manager:

1. Open Window > Package Manager
2. Click + > Add package from disk... (or add to Packages/manifest.json)
3. Ensure XRI Starter Assets sample is imported (required for XR Origin prefab)

Manual Testing (MenuItems)

All building blocks are accessible via the Unity menu:

• PICO MCP > VST > Ensure / Remove
• PICO MCP > Controller > Ensure / Remove
• PICO MCP > Locomotion > Enable / Disable / Configure...
• PICO MCP > Spatial Mesh > Ensure / Remove
• PICO MCP > Packages > ...

License

Copyright (c) 2015-2022 PICO Technology Co., Ltd. All rights reserved. See LICENSE.md for details.