mcpyvisa 2026.2.25

FastMCP server for test equipment via pyvisa — GPIB, USB-TMC, LAN, and more

mcpyvisa

MCP server for test equipment. Connects any MCP client (Claude Code, Claude Desktop, etc.) to instruments via pyvisa - GPIB, USB-TMC, LAN/VXI-11, or simulated hardware.

Docs: mcpyvisa.warehack.ing

Install

pip install mcpyvisa
# or
uv add mcpyvisa

Optional extras for specific backends and features:

pip install mcpyvisa[ar488]      # GPIB via AR488/Prologix adapters
pip install mcpyvisa[pyvisa-py]  # USB-TMC, LAN/VXI-11
pip install mcpyvisa[pymeasure]  # Validated drivers for 8 instruments
pip install mcpyvisa[sim]        # Simulated instruments (no hardware needed)
pip install mcpyvisa[all]        # Everything

Add to Claude Code

claude mcp add mcpyvisa -- uvx mcpyvisa

The server runs over stdio. Works with any MCP client.

Configure

Create mcpyvisa.toml in the current directory or ~/.config/mcpyvisa/config.toml:

[server]
log_level = "INFO"

# AR488/Prologix adapter on serial
[[backend]]
name = "bench"
type = "ar488"
transport = "serial"
port = "/dev/ttyUSB0"
baudrate = 115200

# Give instruments friendly names
[instruments.dmm]
resource = "GPIB0::22::INSTR"
backend = "bench"

[instruments.smu]
resource = "GPIB0::24::INSTR"
backend = "bench"

Config search order: $MCPYVISA_CONFIG, ./mcpyvisa.toml, ~/.config/mcpyvisa/config.toml.

Backends

Type	Extra	What it connects to
ar488	mcpyvisa[ar488]	GPIB instruments via AR488 or Prologix adapters (serial or TCP)
pyvisa-py	mcpyvisa[pyvisa-py]	USB-TMC and LAN/VXI-11 instruments
system	(none)	NI-VISA or Keysight IO Libraries
sim	mcpyvisa[sim]	Simulated instruments from YAML definitions

Multiple backends can be active simultaneously. A GPIB bus on serial and a LAN scope work side-by-side through the same server.

Tools (22)

Universal - server_status, connect_backend, disconnect_backend, discover_instruments, instrument_query, instrument_write, instrument_identify, instrument_reset

GPIB - instrument_clear, serial_poll, check_srq, bus_trigger, interface_clear, instrument_local, instrument_remote

AR488 - ar488_command, ar488_diagnostic, configure_ar488

pymeasure (when installed) - instrument_inspect, instrument_get, instrument_set, instrument_call

What a session looks like

You:    Connect to the bench backend and see what's on the bus.

Claude: [connect_backend("bench")] Connected.
        [discover_instruments("bench")] Found 3 instruments:
          GPIB0::5::INSTR   - HP 34401A multimeter
          GPIB0::22::INSTR  - Keithley 2400 SourceMeter
          GPIB0::10::INSTR  - HP 33120A function generator

You:    Measure DC voltage on the DMM.

Claude: [instrument_query("dmm", "MEAS:VOLT:DC?")] -0.00342 V

Try without hardware

Install the sim backend and point it at the included instrument catalog:

[[backend]]
name = "virtual-bench"
type = "sim"
sim_file = "gpib-catalog/sim/all_instruments.yaml"

This gives you 16 simulated instruments that respond to *IDN? and basic SCPI.

pymeasure drivers

When mcpyvisa[pymeasure] is installed, 4 additional tools let you interact with instruments through validated, property-based drivers instead of raw SCPI. Supported instruments:

HP 33120A, HP 34401A, HP 3478A, HP 8657B, Agilent 4284A, Keithley 2000, Keithley 2400, Keithley 6517B

Requirements

• Python 3.11+
• pyvisa >= 1.13
• fastmcp >= 3.0

Links

• Docs: mcpyvisa.warehack.ing
• Repository: git.supported.systems/warehack.ing/mcgpib
• pyvisa-ar488: Standalone pyvisa backend included in this repo

License

MIT