♪ Melo

Agentic Roblox Studio MCP — script diffs, bulk ops, playtest automation, and a cat that sleeps.

Melo is a next-generation MCP server + Studio plugin that combines the best of BoshyXD's community MCP (39+ tools, bulk ops, grep, builds library) with Roblox's official MCP (playtest automation, virtual input, multi-instance) — then pushes beyond both.

What makes Melo different

Script diff review — GitHub-style inline diffs inside the Studio plugin. Accept/reject individual hunks before they commit. Rejected hunks feed back as context so the agent can iterate.
45+ tools — the full superset of both MCPs, unified in one package.
Transaction-safe batch ops — mass operations rollback atomically on failure.
Animated mascot — a sleeping cat that wakes up when the agent is working. Because why not.
Activity feed — real-time log of every MCP tool call with timing and status.
Mode system — switch between Full, Inspector (read-only), and Sandbox from the plugin.
Agentic loop support — auto-accept mode for unattended plan → write → test → fix cycles.

Quick start

1. Install the MCP server

# Claude Code
claude mcp add melo -- npx -y melo-mcp-server@latest

# Or in your MCP config (Claude Desktop, Cursor, etc.)
{
  "mcpServers": {
    "melo": {
      "command": "npx",
      "args": ["-y", "melo-mcp-server@latest"]
    }
  }
}

2. Install the Studio plugin

# Build and install the .rbxmx plugin automatically
npm run install-plugin --workspace=packages/server

This builds MeloMCP.rbxmx and copies it to your local plugins folder:

macOS: ~/Documents/Roblox/Plugins/
Windows: %LOCALAPPDATA%/Roblox/Plugins/

3. Enable HTTP requests

Game Settings → Security → ✅ Allow HTTP Requests

4. Connect

Click the "Melo" button in the Plugins toolbar. The cat should wake up.

Architecture

┌─────────────────────┐    stdio     ┌──────────────────────┐
│   Claude Code CLI   │◄────────────►│   Melo MCP Server    │
│   (or any MCP       │              │   (TypeScript/Node)  │
│    client)          │              │                      │
└─────────────────────┘              │  ┌────────────────┐  │
                                     │  │  Diff Engine    │  │
                                     │  │  (Myers' algo)  │  │
                                     │  └────────────────┘  │
                                     │  ┌────────────────┐  │
                                     │  │  HTTP Bridge    │  │
                                     │  │  (long-poll)    │  │
                                     │  └───────┬────────┘  │
                                     └──────────┼───────────┘
                                                │ HTTP localhost:3002
                                     ┌──────────┼───────────┐
                                     │  Studio  │  Plugin   │
                                     │  ┌───────▼────────┐  │
                                     │  │  Request       │  │
                                     │  │  Router        │  │
                                     │  └───────┬────────┘  │
                                     │  ┌───────▼────────┐  │
                                     │  │  Handlers      │  │
                                     │  │  (per domain)  │  │
                                     │  └───────┬────────┘  │
                                     │  ┌───────▼────────┐  │
                                     │  │  Widget UI     │  │
                                     │  │  Cat + Diffs   │  │
                                     │  └────────────────┘  │
                                     └──────────────────────┘

Tool registry (45+)

Navigation

get_file_tree · get_project_structure · get_place_info · get_services · list_roblox_studios · set_active_studio

Search & Inspection

search_files · search_objects · search_by_property · get_instance_properties · get_instance_children · get_class_info · get_selection · grep_scripts · mass_get_property

Script Editing (with diff staging)

get_script_source · set_script_source · patch_script · grep_replace · execute_luau · run_code

Instance Manipulation

create_object · delete_object · set_property · mass_create_objects · mass_set_property · mass_duplicate · smart_duplicate · set_calculated_property

Playtest Automation

start_playtest · stop_playtest · get_playtest_output · get_studio_mode · run_script_in_play_mode · user_mouse_input · user_keyboard_input · character_navigation

Diff & Meta

get_diff_queue · resolve_diff · get_activity_log · set_mode · rollback

Attributes & Tags

get_attribute · get_attributes · get_tags · get_tagged

Build Library & Assets

export_build · import_build · list_library · insert_model · capture_screenshot

Development

# Clone and install
git clone https://github.com/your-org/melo.git
cd melo
npm install

# Build
npm run build

# Dev mode (auto-rebuild)
npm run dev

Project structure

melo/
├── package.json              # Root workspace config
├── packages/
│   ├── server/               # MCP server (TypeScript)
│   │   ├── src/
│   │   │   ├── index.ts      # Entry point — boots MCP + HTTP bridge
│   │   │   ├── types.ts      # Core type definitions
│   │   │   ├── constants.ts  # Configuration constants
│   │   │   ├── services/
│   │   │   │   ├── bridge.ts       # HTTP long-poll bridge
│   │   │   │   └── diff-engine.ts  # Myers' diff computation
│   │   │   └── tools/
│   │   │       ├── _helpers.ts     # Shared tool utilities
│   │   │       ├── navigation.ts   # File tree, project structure
│   │   │       ├── search.ts       # Search, grep, inspection
│   │   │       ├── script.ts       # Script read/write with diff staging
│   │   │       ├── instance.ts     # Create, delete, bulk ops
│   │   │       ├── playtest.ts     # Playtest automation, virtual input
│   │   │       └── diff-meta.ts    # Diff review, activity log, modes
│   │   ├── package.json
│   │   └── tsconfig.json
│   └── plugin/               # Roblox Studio plugin (Luau)
│       └── src/
│           └── plugin.luau   # Full plugin — UI, handlers, mascot
└── README.md

License

MIT

Melo