screen-buffer-mcp

MCP server for fast Android screenshots via scrcpy frame buffer (~50ms latency).

<!-- mcp-name: io.github.vladkarpman/screen-buffer-mcp -->

Features

• Fast screenshots via scrcpy frame buffer (~50ms vs ~500ms with adb)
• 10-frame circular buffer for instant access to recent frames
• Historical frame access via device_get_frame for debugging/recording
• Automatic fallback to adb when scrcpy unavailable
• Works with Claude Code and any MCP-compatible client

Requirements

• macOS 12+ or Linux
• Python 3.11+
• adb (Android Debug Bridge)
• scrcpy 3.x installed
• Android device connected via USB

Usage with Claude Code

Add to your .mcp.json:

{
  "mcpServers": {
    "screen-buffer": {
      "command": "uvx",
      "args": ["screen-buffer-mcp"]
    }
  }
}

Or add globally:

claude mcp add screen-buffer -s user -- uvx screen-buffer-mcp

Available Tools

Tool	Description	Latency
device_screenshot	Capture latest frame from buffer	~50ms (scrcpy) / ~500ms (adb)
device_get_frame	Get historical frame at offset	~10ms
device_list	List connected devices	~100ms
device_screen_size	Get screen dimensions	~10ms
device_backend_status	Check active backend	instant

How It Works

The server maintains a 10-frame circular buffer from the scrcpy video stream:

1. scrcpy backend (preferred): Connects to scrcpy server on device in video-only mode. Continuously captures frames at ~60fps into a circular buffer. Screenshots return the latest buffered frame instantly.

2. adb backend (fallback): Uses adb exec-out screencap -p for screenshots. Works everywhere but slower (~500ms per screenshot).

Frame Buffer

The frame buffer stores the last 10 frames (~160ms at 60fps), enabling:

• Instant screenshots: Latest frame always ready, no capture delay
• Historical access: Get frames from before an action for debugging
• Recording support: Extract frames at specific offsets

# Get latest screenshot
device_screenshot()

# Get frame from 100ms ago (offset 6 at 60fps)
device_get_frame(offset=6)

Configuration

Environment Variables

• SCREEN_BUFFER_LOG_LEVEL: Set logging level (DEBUG, INFO, WARNING, ERROR)

Multiple Devices

Specify device ID for multi-device setups:

device_screenshot(device="RFCW318P7NV")

Use with mobile-mcp

For full device control (taps, swipes, typing), combine with mobile-mcp:

{
  "mcpServers": {
    "screen-buffer": {
      "command": "uvx",
      "args": ["screen-buffer-mcp"]
    },
    "mobile-mcp": {
      "command": "npx",
      "args": ["-y", "@mobilenext/mobile-mcp@latest"]
    }
  }
}

• screen-buffer-mcp: Fast screenshots (~50ms)
• mobile-mcp: Device input (tap, swipe, type)

Development

git clone https://github.com/vladkarpman/screen-buffer-mcp
cd screen-buffer-mcp
pip install -e ".[dev]"
pytest

License

MIT License - see LICENSE for details.

Related Projects

• mobile-mcp - Official Anthropic mobile MCP
• MYScrcpy - Python scrcpy client
• Claude Code - AI coding assistant