MCP Rs485

What mcp-rs485 does

The mcp-rs485 MCP server gives an MCP-compatible assistant access to RS485 serial communication. It can enumerate serial ports, open and close device connections, inspect connection status, read incoming bytes, and send outgoing bytes. Connections are represented by IDs returned when a device is opened.

Data transfer uses hexadecimal strings. For example, a request can send a frame such as 01 03 00 00 00 0A, and a read operation returns received data as a hexadecimal string. This makes the server suitable for direct serial exchanges where the assistant needs to construct or inspect device messages.

How it works

The mcp-rs485 MCP server exposes its operations as MCP tools rather than requiring the client to call Python functions directly. A typical interaction starts with list_ports to identify available serial devices. The client then calls connect_rs485 with a port path and serial parameters, receives a connection ID, and uses that ID for reading, writing, status checks, and disconnection.

connect_rs485 accepts a port such as /dev/ttyUSB0. Its configurable communication parameters include a default baud rate of 9600, parity set to none by default, one stop bit, eight data bits, and a one-second read timeout. read_rs485 accepts a maximum byte length, while write_rs485 reports the number of bytes written.

Setup and configuration

Install the package with pip:

pip install mcp-rs485

Register it in an MCP client by launching the mcp-rs485 command. The supplied configuration uses the server name mcp-rs485, the command mcp-rs485, and an empty environment-variable map:

{
  "mcpServers": {
    "mcp-rs485": {
      "command": "mcp-rs485",
      "env": {},
      "name": "io.github.daedalus/mcp-rs485"
    }
  }
}

The repository also documents an editable installation for development, followed by pytest, Ruff formatting and linting, and mypy checks.

Tools and capabilities

• list_ports: returns available serial ports with port, description, and hardware-ID fields.
• connect_rs485: opens a connection using the selected serial settings and returns a connection ID.
• disconnect_rs485: closes an existing RS485 connection.
• read_rs485: reads up to the requested number of bytes and returns hexadecimal data.
• write_rs485: sends hexadecimal data and returns the byte count.
• get_connection_status: returns connection state and statistics.

Limitations and notes

Modbus RTU is shown as an example of a message format, not as a separately documented tool or integration.

The connection must be opened before read, write, status, or disconnect operations can use its connection ID. Port paths, serial settings, and message framing must match the attached RS485 device. The documentation does not specify client-specific setup beyond the generic MCP command configuration.