Linkedsword

Roblox Studio MCP server + plugin — 73 tools for script editing, bulk operations, playtest automation, and more.

Linkedsword combines the best of BoshyXD's community MCP (bulk ops, grep, builds library) with Roblox's official MCP (playtest automation, virtual input, multi-instance) into a single package, then adds script diff review on top.

Features

Script diff review — GitHub-style inline diffs inside the Studio plugin. Accept or reject individual hunks before they're applied.
73 tools — navigation, search, script editing, instance manipulation, playtest control, spatial ops, and more.
Batch operations — mass create, duplicate, and set properties across multiple instances.
Activity feed — real-time log of every tool call with timing and status.
Mode system — Full (read + write), Inspector (read-only), or auto-accept for unattended workflows.

Quick start

Prerequisites

Node.js 18+
Roblox Studio

1. Install the MCP server

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

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

2. Install the Studio plugin

# Clone the repo
git clone https://github.com/yannyhl/melo-mcp.git
cd melo-mcp
npm install

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

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

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

3. Enable HTTP requests in Studio

In Roblox Studio: File > Game Settings > Security > Allow HTTP Requests (enable it).

The plugin communicates with the MCP server over HTTP on localhost:3003. This setting is per-place.

4. Connect

Open a place in Roblox Studio.
Click Linkedsword in the Plugins toolbar.
The widget should show a "Connected" status.
Start using tools from your MCP client.

Architecture

MCP Client (Claude Code, Cursor, etc.)
  ── stdio ──>  Linkedsword MCP Server (Node/TypeScript)
                  ├── Diff Engine (Myers' algorithm)
                  └── HTTP Bridge (long-poll, localhost:3003)
                        ── HTTP ──>  Roblox Studio Plugin (Luau)
                                       ├── Tool Handlers
                                       ├── Diff Review UI
                                       └── Activity Feed

Tool registry (73)

Navigation (6)

get_file_tree . get_project_structure . get_place_info . get_services . list_roblox_studios . set_active_studio

Search & Inspection (11)

search_files . search_objects . search_by_property . get_instance_properties . get_instance_children . get_class_info . get_selection . grep_scripts . mass_get_property . set_selection . get_descendants

Script Editing (9 — with diff staging)

get_script_source . set_script_source . patch_script . grep_replace . execute_luau . run_code . edit_script_lines . insert_script_lines . delete_script_lines

Instance Manipulation (13)

create_object . delete_object . set_property . mass_create_objects . mass_set_property . mass_duplicate . smart_duplicate . set_calculated_property . clone_object . reparent_object . group_objects . ungroup_objects . batch_operations

Playtest Automation (8)

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 (21)

get_diff_queue . resolve_diff . get_diff_history . get_activity_log . set_mode . rollback . redo . get_attribute . get_attributes . set_attribute . delete_attribute . get_tags . get_tagged . add_tag . remove_tag . capture_screenshot . export_build . import_build . list_library . insert_model . get_console_output

Spatial (5)

create_weld . get_bounding_box . raycast . fill_terrain . clear_terrain

Development

git clone https://github.com/yannyhl/melo-mcp.git
cd melo-mcp
npm install

# Build server
npx tsup packages/server/src/index.ts --format cjs --out-dir packages/server/dist --clean

# Build plugin
node packages/plugin/build-rbxmx.js

# Deploy plugin to Studio
cp packages/plugin/Linkedsword.rbxmx ~/Documents/Roblox/Plugins/Linkedsword.rbxmx

Local MCP config

Copy .mcp.json.example to .mcp.json and adjust the path if needed:

cp .mcp.json.example .mcp.json

Project structure

melo-mcp/
├── packages/
│   ├── server/               # MCP server (TypeScript)
│   │   ├── src/
│   │   │   ├── index.ts      # Entry point
│   │   │   ├── services/
│   │   │   │   ├── bridge.ts       # HTTP long-poll bridge
│   │   │   │   └── diff-engine.ts  # Myers' diff computation
│   │   │   └── tools/
│   │   │       ├── navigation.ts   # 6 tools
│   │   │       ├── search.ts       # 11 tools
│   │   │       ├── script.ts       # 9 tools
│   │   │       ├── instance.ts     # 13 tools
│   │   │       ├── playtest.ts     # 8 tools
│   │   │       ├── diff-meta.ts    # 21 tools
│   │   │       └── spatial.ts      # 5 tools
│   │   └── package.json
│   └── plugin/               # Roblox Studio plugin (Luau)
│       └── src/
│           └── plugin.luau   # Single-file plugin (~4700 lines)
├── docs/
│   └── README.md             # Internal handbook (architecture, caveats, LLM guide)
├── .mcp.json.example         # MCP config template
└── README.md

Known limitations

Heartbeat timeouts on rapid parallel tool calls (retry works).
MCP server restart requires reloading your editor window.
user_mouse_input and user_keyboard_input are not fully implemented in the plugin.
capture_screenshot is not yet available.
Sandbox mode is declared but not implemented.

See docs/README.md for the full caveats list.

License

MIT

Melo