# VS Code Extension - MCP Integration & Enhancements

## Summary

Extended the HoloScript VSCode extension with MCP server definition provider, enhanced language support, and Studio live preview integration.

## Changes Made

### 1. MCP Server Definition Provider

**Files Created:**
- `src/services/HoloScriptMcpProvider.ts` - Main MCP provider implementation
- `src/types/vscode-mcp.d.ts` - TypeScript type definitions for VS Code MCP API

**Files Modified:**
- `package.json` - Added `mcpServerDefinitionProviders` contribution point with ID `holoscriptMcp`
- `package.json` - Added configuration setting `holoscript.mcp.holoscriptMcpEnabled`
- `src/extension.ts` - Registered MCP provider in activation function

**Features:**
- Registers HoloScript MCP server at `https://mcp.holoscript.net/mcp` with VS Code
- Uses Streamable HTTP transport for GitHub Copilot and AI agent integration
- Provides 65+ HoloScript language tools to AI agents
- Health check before server resolution
- Graceful fallback if MCP API not available (VS Code < 1.96)

**Configuration:**
```json
{
  "holoscript.mcp.holoscriptMcpEnabled": true
}
```

### 2. Enhanced Live Preview Command

**Files Modified:**
- `package.json` - Added `holoscript.openStudioPreview` command
- `src/extension.ts` - Implemented Studio live preview launcher

**Features:**
- Opens HoloScript files in Studio (https://holoscript.net/studio) for live 3D preview
- Encodes current file content in URL for instant preview
- Launches in external browser with full Studio viewport

**Usage:**
- Command Palette: "HoloScript: Open Studio Live Preview"
- Opens current .holo or .hsplus file in Studio web interface

### 3. Enhanced Syntax Highlighting

**Files Modified:**
- `syntaxes/holoscript.tmLanguage.json`

**Enhancements:**
- **Interaction traits:** Added `resizable`, `attachable`
- **Visual traits:** Added `dissolve`, `fade`, `shimmer`, `holographic`
- **AI/Behavior traits:** Added `decision_tree`, `state_machine`, `planning`, `learning`
- **Physics traits:** Added `constraint`, `ragdoll`, `vehicle`
- **Spatial/XR traits:** New category with `eye_tracking`, `passthrough`, `spatial_mesh`
- **Networking traits:** New category with `replicated`, `authoritative`, `client_predicted`, `interpolated`, `owner_only`, `sync`
- **Character/Animation traits:** New category with `ik`, `motion_capture`
- **Hologram media traits:** New category with `depth_estimation`, `displacement`, `quilt`, `gaussian_splatting`, `spatial_video`, `temporal_smoothing`, `depth_to_normal`
- **GAPS traits:** New category with `fluid`, `volumetric_clouds`, `god_rays`, `weather_hub`, `world_state`, `quality_tier`, `token_gated`
- **Test trait:** Explicit highlighting for `@test`
- **Additional traits:** `@wot_thing`, `@snn`
- **Keywords:** Added `composition`, `object`, `behavior`, `logic`, `state`, `into`, `with`, `from`
- **Actions:** Added `fs_read`, `fs_write`, `fs_exists`, `fs_delete`, `process_exec`, `net_fetch`, `read_candidate`, `generate_fix`, `apply_fix`, `write_result`
- **Primitives:** Added `torus`, `capsule`, `point_cloud`, `trigger_zone`, `BehaviorTree`, `Node`, `Sequence`, `Selector`, `Action`, `Condition`

**Total Trait Coverage:**
- 100+ traits now have category-specific syntax highlighting
- 10 trait categories for color-coded visual distinction
- Future-proof catch-all pattern for custom traits

## Testing & Verification

### Build Status
- TypeScript compilation: ✅ No errors in new files
- Type safety: ✅ Full IntelliSense support via type declarations
- Extension manifest: ✅ Valid contribution points

### Pre-existing Issues
The extension has some pre-existing test failures unrelated to these changes:
- AgentKitService test type mismatches (missing `to` field in RoyaltyEvent)
- HoverProvider mock vs real vscode Position interface differences
- QuestBuilderService missing `id` field in test fixtures
- X402PaymentService bigint/number type mismatch

These are legacy test issues and don't affect the new MCP integration.

## VS Code Version Requirements

### MCP Server Definition Provider
- **Minimum:** VS Code 1.96+ (Insiders as of March 2026)
- **Fallback:** Extension detects API availability and gracefully skips registration on older versions
- **Check:** Uses `if (vscode.lm && vscode.lm.registerMcpServerDefinitionProvider)` guard

### Other Features
- **Live Preview:** Works on all VS Code versions (uses external browser)
- **Syntax Highlighting:** Works on all VS Code versions

## Usage for AI Agents

Once registered, GitHub Copilot and other AI agents in VS Code can access HoloScript MCP tools:

**Example queries:**
- "Parse this HoloScript code and check for errors"
- "Generate a 3D scene with a rotating cube"
- "What traits are available for physics simulation?"
- "Compile this to Unity"
- "Search the codebase for all uses of @grabbable"

**Available Tool Categories:**
- Code parsing and validation (15 tools)
- Graph understanding (6 tools)
- IDE integration (9 tools)
- AI assistance via Brittney-Lite (4 tools)
- Codebase intelligence (5 tools)
- Compilation to 28+ targets (9+ tools)
- And more (65+ total tools)

## Documentation References

- [VS Code MCP Developer Guide](https://code.visualstudio.com/api/extension-guides/ai/mcp)
- [HoloScript MCP Server](https://mcp.holoscript.net/.well-known/mcp)
- [HoloScript Studio](https://holoscript.net/studio)

## Related GitHub Issues

- [microsoft/vscode#243522](https://github.com/microsoft/vscode/issues/243522) - MCP API for extensions
- [microsoft/vscode#258807](https://github.com/microsoft/vscode/issues/258807) - MCP provider registration

## Author

Implementation by HoloScript Autonomous Administrator v3.0
Date: 2026-03-21
