Ryan Malloy
5c655fe743
- open_serial_port now accepts URL schemes (socket://, rfc2217://, loop://, spy://, cp2110://) via serial_for_url() - cp2110 HID-to-UART support gated behind optional [cp2110] extra - Add grep parameter to list_serial_ports for regex filtering - Add read_serial_lines for batch multi-line reads - Add cancel_read/cancel_write for pending I/O interruption - Add set_flow_control for manual XON/XOFF gating - Add break_condition to get_modem_lines response
MCP Serial Server
FastMCP server for serial port access via Model Context Protocol.
Features
- RS-232 Mode: Full modem control (RTS, DTR, CTS, DSR, RI, CD)
- RS-485 Mode: Half-duplex bus communication with auto direction control
- File Transfer: X/Y/ZMODEM protocols for reliable file transfers
- Auto-baud Detection: Smart detection using 0x55 sync pattern analysis
- Dynamic Resources: Read data via
serial://{port}/data - Full pyserial support (baudrate, parity, stop bits, flow control)
Installation
# With uvx (recommended)
uvx mcserial
# Or install directly
uv pip install mcserial
Usage with Claude Code
# Add to Claude Code
claude mcp add mcserial "uvx mcserial"
Modes
Ports open in RS-232 mode by default. Switch with set_port_mode():
| Mode | Use Case | Tools |
|---|---|---|
| RS-232 | Point-to-point serial | get_modem_lines, set_modem_lines, pulse_line, send_break |
| RS-485 | Multi-drop bus (Modbus) | set_rs485_mode, rs485_transact, rs485_scan_addresses |
Tools
Common (both modes)
| Tool | Description |
|---|---|
list_serial_ports |
Discover available serial ports |
open_serial_port |
Open connection (auto-detects baud if not specified) |
close_serial_port |
Close a connection |
set_port_mode |
Switch between RS-232 and RS-485 modes |
write_serial |
Send text data |
write_serial_bytes |
Send raw bytes |
read_serial |
Read available data |
read_serial_line |
Read until newline |
read_until |
Read until custom terminator |
configure_serial |
Change port settings |
flush_serial |
Clear buffers |
get_connection_status |
List open connections with mode |
detect_baud_rate |
Auto-detect baud rate |
RS-232 Mode
| Tool | Description |
|---|---|
get_modem_lines |
Read CTS, DSR, RI, CD, RTS, DTR states |
set_modem_lines |
Control RTS and DTR outputs |
pulse_line |
Pulse RTS/DTR for reset sequences |
send_break |
Send timed break signal |
set_break_condition |
Hold/release break state |
RS-485 Mode
| Tool | Description |
|---|---|
set_rs485_mode |
Configure hardware RS-485 (DE/RE control) |
check_rs485_support |
Detect hardware RS-485 capability |
rs485_transact |
Send/receive with automatic turnaround |
rs485_scan_addresses |
Scan bus for responding devices |
File Transfer
| Tool | Description |
|---|---|
file_transfer_send |
Send file via XMODEM/YMODEM/ZMODEM |
file_transfer_receive |
Receive file via XMODEM/YMODEM/ZMODEM |
file_transfer_send_batch |
Send multiple files (YMODEM/ZMODEM) |
Protocols:
xmodem- 128-byte blocks, simple (1977)xmodem1k- 1024-byte blocksymodem- Batch mode with filename/sizezmodem- Streaming, auto-resume (recommended)
Resources
| URI | Description |
|---|---|
serial://ports |
List available ports |
serial://{port}/data |
Read data from open port |
serial://{port}/status |
Port config and mode |
serial://{port}/raw |
Read as hex dump |
Environment Variables
| Variable | Default | Description |
|---|---|---|
MCSERIAL_DEFAULT_BAUDRATE |
9600 | Default baud rate |
MCSERIAL_DEFAULT_TIMEOUT |
1.0 | Read timeout (seconds) |
MCSERIAL_MAX_CONNECTIONS |
10 | Max concurrent ports |
Example Workflows
Basic RS-232
1. list_serial_ports() → find /dev/ttyUSB0
2. open_serial_port(port="/dev/ttyUSB0") # auto-detects baud
3. write_serial(port="/dev/ttyUSB0", data="AT\r\n")
4. Read resource: serial:///dev/ttyUSB0/data
5. close_serial_port(port="/dev/ttyUSB0")
RS-485 Modbus
1. open_serial_port(port="/dev/ttyUSB0", baudrate=9600)
2. set_port_mode(port="/dev/ttyUSB0", mode="rs485")
3. rs485_scan_addresses(port="/dev/ttyUSB0") # discover devices
4. rs485_transact(port="/dev/ttyUSB0", data="\x01\x03...")
File Transfer
1. open_serial_port(port="/dev/ttyUSB0", baudrate=115200)
2. file_transfer_send(port="/dev/ttyUSB0", file_path="firmware.bin")
License
MIT