Claude KVM

Claude KVM is an MCP tool that controls remote desktop environments over VNC. It consists of a thin JS proxy layer (MCP server) and a platform-native Swift VNC daemon running on your macOS system.

Live Test Runs

• Integration Test
• Mac Integration Test
• Mac Calculator Test
• Mac Scientific Calculator Test
• Mac Safari Browsing Test
• Mac Drag & Drop Test

[!NOTE] Tests are conducted transparently on GitHub Actions — each step is visible in the CI environment. At the end of every test, whether the integration passes or fails, you'll find screenshots of each step the agent took during the session, along with an .mp4 video recording that captures the entire session. By reviewing these recordings and screenshots, you can observe how the agent progressed through each stage, how long the task took, and what decisions were made based on the system prompt. You can use these examples as a reference when crafting your own system prompts or instructions for the MCP server in your own environment.

[!WARNING] Artifacts attached to these runs may have expired due to GitHub's artifact retention policy. Persistent copies are prepared via the Persist Artifacts workflow and can always be accessed by run ID from the artifacts/ directory on the press-kit branch.

Architecture

graph TB
    subgraph MCP["MCP Client (Claude)"]
        AI["Claude"]
    end

    subgraph Proxy["claude-kvm · MCP Proxy (stdio)"]
        direction TB
        Server["MCP Server<br/><code>index.js</code>"]
        Tools["Tool Definitions<br/><code>tools/index.js</code>"]
        Server --> Tools
    end

    subgraph Daemon["claude-kvm-daemon · Native VNC Client (stdin/stdout)"]
        direction TB
        CMD["Command Handler<br/><i>PC Dispatch</i>"]
        Scale["Display Scaling<br/><i>Scaled ↔ Native</i>"]

        subgraph Screen["Screen"]
            Capture["Frame Capture<br/><i>PNG · Crop · Diff</i>"]
            OCR["OCR Detection<br/><i>Apple Vision</i>"]
        end

        subgraph InputGroup["Input"]
            Mouse["Mouse<br/><i>Click · Drag · Move · Scroll</i>"]
            KB["Keyboard<br/><i>Tap · Combo · Type · Paste</i>"]
        end

        VNC["VNC Bridge<br/><i>LibVNCClient 0.9.15</i>"]

        CMD --> Scale
        Scale --> Capture
        Scale --> Mouse
        Scale --> KB
        Capture -.->|"framebuffer"| VNC
        Mouse -->|"pointer events"| VNC
        KB -->|"key events"| VNC
    end

    subgraph Target["Target Machine"]
        VNC_Server["VNC Server<br/><i>:5900</i>"]
        Desktop["Desktop Environment"]
        VNC_Server --> Desktop
    end

    AI <-->|"stdio<br/>JSON-RPC"| Server
    Server <-->|"stdin/stdout<br/>PC (NDJSON)"| CMD
    VNC <-->|"RFB Protocol<br/>TCP :5900"| VNC_Server

    classDef proxy fill:#1a1a2e,stroke:#16213e,color:#e5e5e5
    classDef daemon fill:#0f3460,stroke:#533483,color:#e5e5e5
    classDef target fill:#1a1a2e,stroke:#e94560,color:#e5e5e5

    class Server,Tools proxy
    class CMD,Scale,VNC,Capture,Mouse,KB daemon
    class VNC_Server,Desktop target

Layers

Layer	Language	Role	Communication
MCP Proxy	JavaScript (Node.js)	Communicates with Claude over MCP protocol, manages daemon lifecycle	stdio JSON-RPC
VNC Daemon	Swift/C (Apple Silicon)	VNC connection, screen capture, mouse/keyboard input injection	stdin/stdout PC (NDJSON)

PC (Procedure Call) Protocol

Communication between the proxy and daemon uses the PC protocol over NDJSON:

Request:      {"method":"<name>","params":{...},"id":<int|string>}
Response:     {"result":{...},"id":<int|string>}
Error:        {"error":{"code":<int>,"message":"..."},"id":<int|string>}
Notification: {"method":"<name>","params":{...}}

Coordinate Scaling

The VNC server's native resolution is scaled down to fit within --max-dimension (default: 1280px). Claude works more consistently with scaled coordinates — the daemon handles the conversion in the background:

Native:  4220 x 2568  (VNC server framebuffer)
Scaled:  1280 x 779   (what Claude sees and targets)

mouse_click(640, 400) → VNC receives (2110, 1284)

Screen Strategy

Claude minimizes token cost with a progressive verification approach:

diff_check       →  changeDetected: true/false     ~5ms    (text only, no image)
detect_elements  →  OCR text + bounding boxes      ~50ms   (text only, no image)
cursor_crop      →  crop around cursor              ~50ms   (small image)
screenshot       →  full screen capture             ~200ms  (full image)

detect_elements uses Apple Vision framework for on-device OCR. Returns text content with bounding box coordinates in scaled space — enables precise click targeting without consuming vision tokens.

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Installation

Requirements

• macOS (Apple Silicon / aarch64)
• Node.js (LTS)

Daemon

brew tap ARAS-Workspace/tap
brew install claude-kvm-daemon

[!NOTE] claude-kvm-daemon is compiled and code-signed via CI (GitHub Actions). The build output is packaged in two formats: a .tar.gz archive for Homebrew distribution and a .dmg disk image for notarization. The DMG is submitted to Apple servers for notarization within the same workflow — the process can be tracked from CI logs. The notarized DMG is available as a CI Artifact; the archived .tar.gz is also published as a release on the repository. Homebrew installation tracks this release.

• Release · Source Code
• LibVNC Build · LibVNC Branch
• Homebrew Tap

MCP Configuration

Create a .mcp.json file in your project directory:

{
  "mcpServers": {
    "claude-kvm": {
      "command": "npx",
      "args": ["-y", "claude-kvm"],
      "env": {
        "VNC_HOST": "192.168.1.100",
        "VNC_PORT": "5900",
        "VNC_USERNAME": "user",
        "VNC_PASSWORD": "pass",
        "CLAUDE_KVM_DAEMON_PATH": "/opt/homebrew/bin/claude-kvm-daemon",
        "CLAUDE_KVM_DAEMON_PARAMETERS": "-v"
      }
    }
  }
}

[!NOTE] The tool is end-to-end tested via CI — Claude executes tasks over VNC while an independent vision model observes and verifies the results. See the Integration Test for live workflow runs, system prompts, and demo recordings.

Configuration

MCP Proxy (ENV)

Parameter	Default	Description
VNC_HOST	127.0.0.1	VNC server address
VNC_PORT	5900	VNC port number
VNC_USERNAME		Username (required for ARD)
VNC_PASSWORD		Password
CLAUDE_KVM_DAEMON_PATH	claude-kvm-daemon	Daemon binary path (not needed if already in PATH)
CLAUDE_KVM_DAEMON_PARAMETERS		Additional CLI arguments for the daemon

Daemon Parameters (CLI)

Additional arguments passed to the daemon via CLAUDE_KVM_DAEMON_PARAMETERS:

"CLAUDE_KVM_DAEMON_PARAMETERS": "--max-dimension 800 -v"

Parameter	Default	Description
--max-dimension	1280	Maximum display scaling dimension (px)
--connect-timeout		VNC connection timeout (seconds)
--bits-per-sample		Bits per pixel sample
--no-reconnect		Disable automatic reconnection
-v, --verbose		Verbose logging (stderr)

Runtime Configuration (PC)

All timing and display parameters are configurable at runtime via the configure method. Use get_timing to inspect current values.

Set timing:

{"method":"configure","params":{"click_hold_ms":80,"key_hold_ms":50}}

{"result":{"detail":"OK — changed: click_hold_ms, key_hold_ms"}}

Change display scaling:

{"method":"configure","params":{"max_dimension":960}}

{"result":{"detail":"OK — changed: max_dimension","scaledWidth":960,"scaledHeight":584}}

Reset to defaults:

{"method":"configure","params":{"reset":true}}

{"result":{"detail":"OK — reset to defaults","timing":{"click_hold_ms":50,"combo_mod_ms":10,"cursor_crop_radius":150,"double_click_gap_ms":50,"drag_min_steps":10,"drag_pixels_per_step":20,"drag_position_ms":30,"drag_press_ms":50,"drag_settle_ms":30,"drag_step_ms":5,"hover_settle_ms":400,"key_hold_ms":30,"max_dimension":1280,"paste_settle_ms":30,"scroll_press_ms":10,"scroll_tick_ms":20,"type_inter_key_ms":20,"type_key_ms":20,"type_shift_ms":10},"scaledWidth":1280,"scaledHeight":779}}

Get current values:

{"method":"get_timing"}

{"result":{"timing":{"click_hold_ms":80,"combo_mod_ms":10,"cursor_crop_radius":150,"double_click_gap_ms":50,"drag_min_steps":10,"drag_pixels_per_step":20,"drag_position_ms":30,"drag_press_ms":50,"drag_settle_ms":30,"drag_step_ms":5,"hover_settle_ms":400,"key_hold_ms":50,"max_dimension":1280,"paste_settle_ms":30,"scroll_press_ms":10,"scroll_tick_ms":20,"type_inter_key_ms":20,"type_key_ms":20,"type_shift_ms":10},"scaledWidth":1280,"scaledHeight":779}}

Parameter	Default	Description
max_dimension	1280	Max screenshot dimension
cursor_crop_radius	150	Cursor crop radius (px)
click_hold_ms	50	Click hold duration
double_click_gap_ms	50	Double-click gap delay
hover_settle_ms	400	Hover settle wait
drag_position_ms	30	Pre-drag position wait
drag_press_ms	50	Drag press hold threshold
drag_step_ms	5	Between interpolation pts
drag_settle_ms	30	Settle before release
drag_pixels_per_step	20	Point density per pixel
drag_min_steps	10	Min interpolation steps
scroll_press_ms	10	Scroll press-release gap
scroll_tick_ms	20	Inter-tick delay
key_hold_ms	30	Key hold duration
combo_mod_ms	10	Modifier settle delay
type_key_ms	20	Key hold during typing
type_inter_key_ms	20	Inter-character delay
type_shift_ms	10	Shift key settle
paste_settle_ms	30	Post-clipboard write wait

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Tools

All operations are performed through a single vnc_command tool:

Screen

Action	Parameters	Description
screenshot		Full screen PNG capture
cursor_crop		Crop around cursor with crosshair overlay
diff_check		Detect screen changes against baseline
set_baseline		Save current screen as diff reference

Mouse

Action	Parameters	Description
mouse_click	x, y, button?	Click (left|right|middle)
mouse_double_click	x, y	Double click
mouse_move	x, y	Move cursor
hover	x, y	Move + settle wait
nudge	dx, dy	Relative cursor movement
mouse_drag	x, y, toX, toY	Drag from start to end
scroll	x, y, direction, amount?	Scroll (up|down|left|right)

Keyboard

Action	Parameters	Description
key_tap	key	Single key press (enter|escape|tab|space|...)
key_combo	key or keys	Modifier combo ("cmd+c" or ["cmd","shift","3"])
key_type	text	Type text character by character
paste	text	Paste text via clipboard

Detection

Action	Parameters	Description
detect_elements		OCR text detection with bounding boxes (Apple Vision)

Returns text elements with bounding box coordinates in scaled space:

{"method":"detect_elements"}

{"result":{"detail":"13 elements","elements":[{"confidence":1,"h":9,"text":"Finder","w":32,"x":37,"y":6},{"confidence":1,"h":9,"text":"File","w":15,"x":84,"y":6},{"confidence":1,"h":9,"text":"Edit","w":19,"x":112,"y":6},{"confidence":1,"h":9,"text":"View","w":22,"x":143,"y":6},{"confidence":1,"h":11,"text":"Go","w":15,"x":179,"y":6},{"confidence":1,"h":9,"text":"Window","w":35,"x":207,"y":6},{"confidence":1,"h":11,"text":"Help","w":22,"x":255,"y":6},{"confidence":1,"h":11,"text":"8•","w":26,"x":1161,"y":6},{"confidence":1,"h":9,"text":"Fri Feb 20 22:19","w":80,"x":1189,"y":6},{"confidence":1,"h":9,"text":"Assets","w":32,"x":1202,"y":97},{"confidence":1,"h":9,"text":"Passwords.kdbx","w":74,"x":1181,"y":168},{"confidence":1,"h":93,"text":"PHANTOM","w":633,"x":322,"y":477},{"confidence":1,"h":32,"text":"YOUR SERVER, YOUR NETWORK, YOUR PRIVACY","w":629,"x":325,"y":568}],"scaledHeight":717,"scaledWidth":1280}}

Configuration

Action	Parameters	Description
configure	{<params>}	Set timing/display params at runtime
configure	{reset: true}	Reset all params to defaults
get_timing		Get current timing + display params

Control

Action	Parameters	Description
wait	ms?	Wait (default 500ms)
health		Connection status + display info
shutdown		Graceful daemon shutdown

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Authentication

Supported VNC authentication methods:

• VNC Auth — password-based challenge-response (DES)
• ARD — Apple Remote Desktop (Diffie-Hellman + AES-128-ECB)

macOS is auto-detected via the ARD auth type 30 credential request. When detected, Meta keys are remapped to Super (Command key compatibility).

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Copyright (c) 2026 Riza Emre ARAS — MIT License