RPG Maker MV MCP Server

RPG Maker MV MCP Server

A Model Context Protocol server that turns AI assistants (Claude Code, Claude Desktop, or any MCP client) into a co-developer for RPG Maker MV projects — with automatic backups of everything it touches.

Ask your assistant things like:

"Create a Fireball skill: magical damage, a.mat * 4 - b.mdf * 2, 12 MP, fire element." "Find every event in the game that mentions the mayor." "Add a guard to the castle gate who says 'Halt! Who goes there?'" "Rebalance all weapons: +10% attack across the board." "Validate the project — anything broken?"

Highlights

• Full database access — all 12 database types (actors, classes, skills, items, weapons, armors, enemies, troops, states, animations, tilesets, common events) plus System.json, through a compact generic CRUD interface.
• High-level skill builders — create complete, editor-valid damage / healing / buff / state skills from just a name and a formula.
• Maps and events — create maps, create/edit/delete events, insert event commands in batches, add dialogue with automatic message-box splitting, and consult a built-in event command code reference.
• Search everywhere — substring search across every database, and across every event on every map, including inside event command lists (find which event shows a line of dialogue or runs a script).
• Plugin management — enable/disable/configure plugins, scaffold new ones, edit plugin source, all in the editor's own js/plugins.js format.
• Playtest control — launch the game through NW.js (auto-detected from common install locations) with stdout/stderr capture, or serve it to a browser via the built-in HTTP server.
• Safety net — every file is snapshotted to .mcp-backups/ before its first modification each session; restore_backup rolls anything back, and validate_project catches broken references before you ship.

Installation

Requires Node.js 18+.

Quick start (npm)

The easiest way for Claude Code or Claude Desktop users:

npm install -g @xerolo44/rpgmaker-mv-mcp

Then configure it (see below). The package is available on npmjs.com and in the MCP Registry.

Configure Claude Code

claude mcp add rpgmaker-mv -- npx @xerolo44/rpgmaker-mv-mcp --project "/path/to/YourGame"

Configure Claude Desktop

Add to claude_desktop_config.json:

{
  "mcpServers": {
    "rpgmaker-mv": {
      "command": "npx",
      "args": [
        "@xerolo44/rpgmaker-mv-mcp",
        "--project", "/path/to/YourGame"
      ]
    }
  }
}

--project is optional — without it, ask the assistant to call set_project first. The project can also be switched mid-session.

Custom connector / URL-based clients (HTTPS) — experimental

Some clients (e.g. "Add custom connector" UIs) don't spawn a local process — they connect to a URL instead. Run the server in HTTPS mode:

node dist/index.js --http [port]   # default port 3939

This starts a Streamable HTTP MCP endpoint at https://127.0.0.1:<port>/mcp, bound to localhost only (never reachable from the network — every request is checked against the connecting socket's address, not just the bind address). A self-signed TLS certificate for localhost/127.0.0.1 is generated on first run and cached in .certs/ (gitignored) next to the project.

Status: the endpoint is fully verified at the protocol level (handshake, session management, and all 41 tools tested directly over HTTPS with curl). What's not guaranteed is that a given GUI connector-adding flow will accept a self-signed localhost certificate — some do (after a manual "proceed anyway" warning, since they open the URL as a normal page), others silently reject it because their background connection check doesn't trust locally-generated certs and gives no user-facing error. If adding the connector spins and fails with no message, that's very likely what's happening, and it's a limitation of that client's trust handling, not of this server. The reliable, zero-friction way to use this server today is the stdio mode above (Claude Code CLI / Claude Desktop's local server config) — reach for --http only if your client specifically requires a URL.

The server process must stay running for the connector to work — start it in its own terminal window before adding the connector, and leave that window open.

Tool reference (41 tools)

Every tool description is written for AI consumption: parameter semantics, RPG Maker quirks (target scopes, command codes, 1-indexed arrays), and pointers to related tools are all in the schema, so assistants can use the server without external documentation.

Backups

The first time a session modifies any file, the original is copied to <project>/.mcp-backups/<session-timestamp>/ preserving its relative path. Up to 10 sessions are kept. list_backups shows what's available; restore_backup restores one file or a whole session — and backs up the current state first, so restores are undoable.

Add .mcp-backups/ to your game project's .gitignore if the game is under version control.

Important notes

• Close the RPG Maker MV editor (or don't save from it) while the server edits files. The editor keeps the whole database in memory and overwrites the JSON files on save, discarding external changes. Reopen the project in the editor to see edits made here.
• Database arrays in MV are 1-indexed with null at index 0; the tools handle this automatically, and ids always match array positions.
• MZ projects (.rmmzproject) are accepted too — the data format is nearly identical — but only MV is regularly tested.
• Tile data editing is intentionally unsupported (create_map makes blank maps; update_map refuses to touch data). Paint tiles in the editor.
• NW.js playtest auto-detects Steam and KADOKAWA install paths, the project's own Game.exe, and the RPGMAKER_MV_NWJS environment variable, in that order.
• In browser playtest mode, console output stays in the browser devtools — use NW.js mode when you need playtest_log.

Building from source

For contributors or if you prefer to build locally:

git clone https://github.com/Xerolo44/RPG-Maker-MV-MCP.git
cd RPG-Maker-MV-MCP
npm install
npm run build

Then use the local build with Claude Code:

claude mcp add rpgmaker-mv -- node "$(pwd)/dist/index.js" --project "/path/to/YourGame"

Development

npm run build   # compile TypeScript to dist/
npm run smoke   # end-to-end test: real stdio client against a generated MV project

See CONTRIBUTING.md for project layout and guidelines, CHANGELOG.md for release history, and SECURITY.md for the tool's trust model (it has full file-system access — read this before exposing --http mode beyond your own machine).

License

MIT