Kairo

An MCP server that turns a described circuit into a checked KiCad project. Every voltage and current is worked out twice, by formulas with cited sources and by simulation (ngspice and Xyce), and anything that could not be checked is marked unverified instead of guessed.

Kairo gives an AI model, such as Claude, the tools to design and check electronics without making numbers up:

• Designs from a description. Pins come only from the KiCad libraries, never from memory; each build is checked by KiCad's own netlist and electrical rules check before anything is written.

• Numbers with sources. Every value comes from a formula with a cited source and its worst case over the parts' tolerances; each requirement is pass, fail or unverified, with what would settle it.

• Simulation in two engines. ngspice and Xyce, judged at the worst case; Monte Carlo is a report and never decides.

• Schematics you drew. Read any KiCad project, check it against the facts you state, simulate parts of it, and change values or parts with KiCad confirming nothing else moved.

• Real parts. Resistors, capacitors, inductors, LEDs and regulators from a parts catalogue; datasheets fetched and their limit tables read.

• Boards. Placement by block and edge, pours, Kairo's own router, and KiCad's DRC against net classes and voltage spacing, with fab files.

• A review. Faults and suggestions, each with its source: rails with no decoupling, switches bypassed by a body diode, floating inputs, crossed UARTs, and on a prototype, rails with no test point, light or link to open, and spare I/O left unreachable.

Install

Releases carry a Claude Desktop extension (kairo.mcpb) and a wheel for Windows, macOS and Linux. You need uv and KiCad 10. See docs/getting-started.md for each client.

Then start a message with Kairo:

Kairo, a 3.3 V rail from 5 V USB for a sensor that draws 120 mA

Related MCP server: KiCAD MCP Server

Documentation

• Getting started: install, connect, the tools and their tiers.

• Board layout and router design: how boards are made.

• Design decisions: each choice made, and why.

• Research: what was studied, and what Kairo took from it, credited.

• Writing code and docs, for contributors.

Development

uv sync                                       # builds the compiled loops; needs Rust
uv run pytest -m "not kicad and not spice"    # drop -m when KiCad and ngspice are installed
uv run ruff check && uv run ruff format --check && uv run pyright
uv run sphinx-build -W docs docs/_build/html  # the documentation site

Licence

Apache License 2.0; see LICENSE. Third-party licences, and the licences of the open-hardware boards used as test data, are listed in NOTICE.