Use MCP client

Qt Creator supports the model context protocol (MCP) to let AI assistants control it for debugging, building, and managing projects.

To use an MCP client, install one and activate the Qt Creator MCP server extension to start the MCP server.

View MCP server status

Qt Creator starts the MCP server when you activate the Qt Creator MCP server extension. The server runs at 127.0.0.1 and accepts connections on port 3001. For security reasons, you cannot run it on a remote computer.

To view the MCP server status, go to Tools > MCP Server > About MCP Server.

If the server does not start, see whether General Messages shows a warning about the port being in use.

Make sure that no other process is bound to the port. For example, on Linux, enter lsof -i :3001 in Terminal.

To use another port than 3001, set the MCP_SERVER_PORT environment variable to configure the port before Qt Creator starts.

Set up a simple MCP client

You can use any HTTP client that can send POST requests and read SSE responses. This section describes how to use pip to install a simple MCP client and how to configure it.

To install and configure a simple MCP client:

1. Go to Terminal, and enter:

   pip install simple-mcp-client

2. Change the simple_mcp_client\config.json configuration file to point to the qtcreator MCP server:

   "mcpServers": {
     "qtcreator": {
       "enable": false,
       "type": "sse",
       "url": "http://127.0.0.1:3001/sse",
       "command": null,
       "args": [],
       "env": {}
     }
   }

You can find the config.json file in the following locations:

• On Linux: ~/.config/simple_mcp_client/
• On Windows: C:\Users\<username>\AppData\Roaming\simple_mcp_client

Run Qt Creator tools

To run Qt Creator tools from the MCP client, start the client and connect to the Qt Creator MCP server.

To start the MCP client and view the list of Qt Creator tools:

1. Go to Terminal, and enter:

   python -m simple_mcp_client.main

2. In Mini MCP Client Network Hub, enter:

   connect qtcreator

3. To view a list of tools, enter:

   tools qtcreator

   

4. To run a tool, enter

   execute qtcreator <tool-name>

   For example:

   execute qtcreator list_sessions

If the SSE connection fails, make sure that the MCP client supports cross-origin resource sharing (CORS). It is an HTTP-header based mechanism that lets servers permit loading resources for other domains, schemes, or ports.

On Windows, the firewall might block inbound connections to localhost. Make sure that the Qt Creator executable can accept local traffic.

If a debug session does not stop when Qt Creator exits, you can manually stop debugging in the Debug mode or increase the timeout by setting the MCP_QUIT_TIMEOUT environment variable to 60 seconds.

Summary of tools

The following table summarizes the Qt Creator tools that the server registers. Each tool is a JSON-RPC method that has a name, human-readable title, description, input and output JSON schema, and a flag indicating whether the tool is read-only.

In addition to the static tools, the plugin registers dynamic tools for triggering the most common Qt Creator actions:

• run_project triggers the Run action.
• build triggers the Build action.
• clean_project triggers the Clean action.
• debug triggers the Debug action.

Dynamic tools take an empty params object and return { "success": true|false }.

Add tools

The MCP Server extension uses Core::ActionManager to create tools with the names shown in the table. The implementation calls QAction::trigger() on the UI thread via McpServer::runOnGuiThread().

Therefore, you can turn any other command that is exposed through ActionManager into an MCP tool by adding a small wrapper in McpServer::initializeToolsForCommands().