serial-console-mcp

Let Claude drive your serial console.

 MIT licensed  ·  Python 3.10+  ·  status: experimental (0.1.0)

This adds a few tools to Claude Desktop so you can talk to anything on a serial port — a network device's console/craft port (Juniper, Cisco, etc.), a radio, rotator, amplifier, antenna switch, or a microcontroller — just by asking Claude.

You do not need to know any programming. After it's installed you talk to Claude normally:

You: What serial ports do you see? Claude: I found two. One looks like a Silicon Labs CP210x on COM4 — that's probably your device.

You: Connect to COM4 at 9600 baud. Claude: Connected.

You: Log in and show me the version.

How it works (the important part)

A serial console isn't a simple question-and-answer channel. It echoes what you type, prints unsolicited messages on its own (logs, interface flaps), and can dump pages of output. So the moment a port is open, a background reader keeps draining it into a buffer. That means Claude can:

• send a command (writes only — doesn't guess when the reply is done), then
• read until a prompt appears (# , > , login: …) to capture the whole reply — even a long one — without cutting it off, or
• read whatever's waiting for streaming/unsolicited output.

This is the same model minicom and expect use, which is why it handles interactive CLIs properly.

The tools

One port is open at a time. The receive buffer is capped at 4 MB; if a device streams for hours unread, the oldest bytes are dropped and status says how many.

The Field Guide

serial-console-mcp Field Guide (PDF) is the operator's manual: what each tool does, every connection setting said in plain language, the console rules, a per-device playbook (craft ports, text CAT, Icom CI-V, rotators and microcontrollers), four worked sessions, and a troubleshooting table. Source is docs/brand/ (HTML + CSS, rendered with WeasyPrint).

Installing

1. Download the installer for your computer from the Releases page (the .exe on Windows, or the .pkg on a Mac) and click through it like any normal program. It sets everything up for you. The installers are unsigned for now, so expect a Gatekeeper / SmartScreen warning.
2. Completely quit Claude Desktop — not just closing the window. On Windows, right-click the Claude icon near the clock and choose Quit. On a Mac, press ⌘Q or choose Claude → Quit.
3. Open Claude Desktop again.
4. In a new chat, type: "What serial ports do you see?" If Claude lists your ports, you're done.

That's the whole thing. There's no separate program to keep open and nothing to configure by hand.

Installing from PyPI

If you already have Python 3.10+ and uv or pipx, you don't need the installer:

uvx serial-console-mcp --version                                   # fetches and runs it
uvx serial-console-mcp configure --command uvx --arg serial-console-mcp

or

pipx install serial-console-mcp
serial-console-mcp configure --command "$(which serial-console-mcp)"

configure writes a serial-console entry into claude_desktop_config.json (merging with whatever is already there and backing the old file up first). Quit and reopen Claude Desktop. serial-console-mcp configure --remove undoes it. Any other MCP client can launch the same command over stdio.

Installing from source (developers)

git clone https://github.com/sbrunner-atx/serial-console-mcp.git
cd serial-console-mcp
uv sync                       # or: python3 -m venv .venv && . .venv/bin/activate && pip install -e . pytest
uv run pytest                 # fake serial port, no hardware needed
uv run serial-console-mcp configure --command "$PWD/.venv/bin/serial-console-mcp"

The package lives in src/serial_console_mcp/: server.py is the MCP server, configure.py the Claude Desktop registrar. See BUILD.md for the installers.

Using it

Plain-English requests work. Some examples:

• "List my serial ports."
• "Connect to the console on /dev/cu.usbserial-10 at 9600 baud."
• "Connect to /dev/cu.BLTH at 38400, 8 data bits, no parity, 1 stop bit, XON/XOFF flow control."
• "Reconnect to the same port as last time." (it remembers)
• "Send a return, then read until the login prompt."
• "Log in as admin and run show interfaces terse, then show me all of it."
• "Just read whatever the device is printing right now."
• "Disconnect when you're done."

For a router/switch console, tell Claude the prompt it should wait for (often # for enable mode or > for user mode) and it will read until it sees it. For an Icom radio (CI-V), tell Claude — it can send the hex commands those radios expect.

If something doesn't work

"No serial ports found."

• Is the device turned on?
• Is the USB cable a real data cable, not a charge-only one? (A very common gotcha.)
• On Windows, open Device Manager and look under Ports (COM & LPT). If nothing's there, Windows needs the cable's driver (often FTDI, CP210x, or CH340).

"Could not open the port" / "access denied."

• A serial port can only be used by one program at a time. Close anything else that might be holding it: a terminal (PuTTY/minicom/screen), WSJT-X, your contest logger, the device's own software.

Claude says it can't access serial ports at all.

• Make sure you fully quit and reopened Claude Desktop after installing.
• Start a brand-new chat and ask "What serial ports do you see?" again.

It connected but a command gets no reply.

• Almost always the baud rate is wrong, or the line ending is wrong for your gear. Most Unix-style consoles want a plain newline (LF); most rigs want a carriage return (CR). Ask Claude to send a return first to draw a fresh prompt.

A word on safety

These tools send exactly what you (through Claude) ask them to send, to whatever device is on the cable. Claude Desktop asks you to approve each tool call, so you see every command before it runs. Read it. A console session on a router or a rig can reconfigure, reboot, or transmit, and this server does not try to guess which commands are dangerous. If something looks wrong, decline it, and keep a real terminal handy for anything you would not want an assistant to type.

License

MIT. See LICENSE.

73!