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UI tools and MCP server

An agent can see and drive the window of CodeAlta Desktop: it takes a screenshot, reads what the window shows, clicks and types. A session of CodeAlta does it for the window it runs in. Another application, such as Claude Code or Codex, does it through the MCP server of CodeAlta.

A session of CodeAlta Desktop that took a screenshot of its window: the tool calls, the picture and the answer of the agent
A session that looks at its own window.

The tools are in CodeAlta Desktop only. They have the names of Chrome DevTools MCP, which agents already know.

Let an agent look at the window

Ask in your own words, in any session:

Take a screenshot of the window and tell me what the Changes tab shows.

Open Settings, go to Appearance and switch to the light theme.

The agent turns the tools on for its session, then uses them. A screenshot appears in the timeline, in an Image read card.

Connect another application

CodeAlta Desktop runs an MCP server on your computer. Open Settings, then CodeAlta MCP.

The CodeAlta MCP page of Settings: the switch of the server, its address, the client configuration and the tools
The address of the server and the configuration of a client.
  1. Click Copy beside Client configuration.
  2. Paste it into the MCP configuration of the other application, for example the .mcp.json file of a project for Claude Code.
{
  "mcpServers": {
    "codealta": {
      "type": "http",
      "url": "http://127.0.0.1:2582/mcp"
    }
  }
}

The application then has the tools of the window, and alta, which runs the commands of CodeAlta: list the projects and the sessions, create a session, send it a prompt.

Tools

Tool What it does
take_snapshot Lists what the window shows, as text. Each element has an identifier that the other tools take.
take_screenshot Takes a picture of the window or of one element. filePath saves it to a file.
click, click_at, hover, drag Use the pointer.
fill, fill_form, type_text, press_key Write text and press keys.
wait_for Waits for a text to appear.
evaluate_script Runs JavaScript in the page of the window.
list_console_messages, list_network_requests Read the console and the requests of the page.
resize_page Gives the window a size.
alta Runs a command of CodeAlta. In the MCP server only: a session has it already.

Address of the server

  • The server listens at http://127.0.0.1:2582/mcp. Only programs on your computer reach it.
  • alta --mcp-port <port> starts CodeAlta with another port. When the usual port is taken, CodeAlta takes a free one: Settings shows the address, and the file ~/.alta/mcp_url.txt holds it.
  • alta --mcp-host <address> listens on another address of your computer. Other computers then reach the server, and send the access token that Settings shows.
  • Turn off Run the MCP server to stop it. CodeAlta remembers the choice.

Good to know

  • An application connected to the server can do in CodeAlta what you can do. Turn the server off on a computer you share with other people.
  • An agent saves a screenshot with filePath. A session saves in the folder it works in.
  • To keep sessions from driving the window, turn off the UI tools plugin in Settings, Plugins.
  • The buttons of the title bar are drawn by the system: a screenshot does not show them.