The Dart Tooling MCP Server exposes Dart and Flutter development tool actions to compatible AI-assistant clients.

Status

WIP. This package is still experimental and is likely to evolve quickly.

Set up your MCP client

Note: all of the following set up instructions require Dart 3.9.0-163.0.dev or later.

The Dart MCP server can work with any MCP client that supports standard I/O (stdio) as the transport medium. To access all the features of the Dart MCP server, an MCP client must support Tools and Resources. For the best development experience with the Dart MCP server, an MCP client should also support Roots.

Here are specific instructions for some popular tools:

Gemini CLI

To configure the Gemini CLI to use the Dart MCP server, edit the .gemini/settings.json file in your local project (configuration will only apply to this project) or edit the global ~/.gemini/settings.json file in your home directory (configuration will apply for all projects).

{
  "mcpServers": {
    "dart": {
      "command": "dart",
      "args": [
        "mcp-server",
        "--experimental-mcp-server", // Can be removed for Dart 3.9.0 or later.
      ]
    }
  }
}

For more information, see the official Gemini CLI documentation for setting up MCP servers.

Gemini Code Assist in VS Code

Note: this currently requires the “Insiders” channel. Follow instructions to enable this build.

Gemini Code Assist's Agent mode integrates the Gemini CLI to provide a powerful AI agent directly in your IDE. To configure Gemini Code Assist to use the Dart MCP server, follow the instructions to configure the Gemini CLI above.

You can verify the MCP server has been configured properly by typing /mcp in the chat window in Agent mode.

For more information see the official Gemini Code Assist documentation for using agent mode.

Cursor

The easiest way to configure the Dart MCP server with Cursor is by clicking the “Add to Cursor” button above.

Alternatively, you can configure the server manually. Go to Cursor -> Settings -> Cursor Settings > Tools & Integrations, and then click “Add Custom MCP” or “New MCP Server” depending on whether you already have other MCP servers configured. Edit the .cursor/mcp.json file in your local project (configuration will only apply to this project) or edit the global ~/.cursor/mcp.json file in your home directory (configuration will apply for all projects) to configure the Dart MCP server:

{
  "mcpServers": {
    "dart": {
      "command": "dart",
      "args": [
        "mcp-server",
        "--experimental-mcp-server" // Can be removed for Dart 3.9.0 or later
      ]
    }
  }
}

For more information, see the official Cursor documentation for installing MCP servers.

GitHub Copilot in VS Code

Note: requires Dart-Code VS Code extension v3.114 or later.

To configure the Dart MCP server with Copilot or any other AI agent that supports the VS Code MCP API, add the following to your VS Code user settings (Command Palette > Preferences: Open User Settings (JSON)):

"dart.mcpServer": true

By adding this setting, the Dart VS Code extension will register the Dart MCP Server configuration with VS Code so that you don‘t have to manually configure the server. Copilot will then automatically configure the Dart MCP server on your behalf. This is a global setting. If you’d like the setting to apply only to a specific workspace, add the entry to your workspace settings (Command Palette > Preferences: Open Workspace Settings (JSON)) instead.

For more information, see the official VS Code documentation for enabling MCP support.

Connecting to Applications

Often, connecting to your running application is as simple as asking your agent to do it, you can say “connect to my flutter web app” or “connect to my web server”.

This works by discovering Dart Tooling Daemon instances on your machine, and then discovering dart and flutter applications that are registered with those instances.

See the sections below for specific hints and details for flutter versus dart apps, as well as hints about how to make this work better in multi-app scenarios, or use fewer tokens.

Flutter Applications

Flutter applications are automatically registered with the Dart Tooling Daemon when running in debug/profile mode, unless --no-dds is passed (the Dart Development Service is actually what spawns DTD, so disabling that disables DTD).

Dart Applications

To connect to a pure Dart application, you need to run the application with the --observe flag. This will start the Dart Tooling Daemon (DTD) and register the application with it.

Pass --print-dtd

Both dart and flutter support the --print-dtd flag to get an explicit reference to the DTD URI for that application. This is especially useful when the agent is spawning the process, because it can avoid having to list all available DTD URIs and trying to pick the right one.

It is recommended to put this instruction in a RULES file so that it is always available to the agent. For example, in a GEMINI.md file in your project:

## Launching Dart and Flutter Applications

- Always pass the `--print-dtd` flag to `dart` or `flutter` when spawning an
  application.
- For `dart` applications, always pass the `--observe` flag to enable the app to
  be connected to.
- Both `--print-dtd` and `--observe` must come before the script name or path
  when spawning `dart` applications: `dart --observe --print-dtd bin/main.dart`.

Tools