altium-claude-skills

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Claude Code skills for Altium hardware design: symbol and footprint authoring, schematic review, and PCB placement.

Written while taking one real board (175 components) from schematic review through to placement.

Install

Windows + PowerShell only — junctions (New-Item -ItemType Junction) and Altium itself are Windows things.

You can hand this repo URL to Claude Code and say "install this". Steps 1-3 below are what it needs to do.

1. Clone

Clone somewhere you will not move. The junctions in step 3 bake an absolute path, so relocating the folder later means recreating them.

git clone https://github.com/ScottJeong/altium-claude-skills.git C:\tools\altium-claude-skills

2. Python 3.12 venv

This is what the scripts run on. Do this before the junctions — the skills will trigger without it, and then every script fails. Why 3.12, and the MCP setup, are under Requirements.

py -3.12 -m venv C:\tools\edatools
C:\tools\edatools\Scripts\python.exe -m pip install altium-monkey pymupdf
C:\tools\edatools\Scripts\python.exe -c "import altium_monkey, pymupdf; print('ok')"

3. Link the three skills as junctions

Into ~/.claude/skills/. Unlike symlinks, junctions need no admin rights, and sync clients see them as ordinary folders.

$repo = "C:\tools\altium-claude-skills"      # wherever you cloned in step 1
foreach ($s in 'altium-library','altium-pcb-placement','altium-schematic-review') {
    New-Item -ItemType Junction -Path "$env:USERPROFILE\.claude\skills\$s" -Target "$repo\$s"
}

Verify

LinkType should read Junction.

Get-ChildItem "$env:USERPROFILE\.claude\skills" |
    Select-Object Name, LinkType, Target

Then open a new Claude Code session and say something like "review this schematic". If it triggers, Claude names the skill as it starts. A skill linked mid-session does not appear in that session.

Junctions bake an absolute path. Move the repo and you must recreate them. If you would rather not use junctions, copy the three folders instead — but then git pull will not reach them.

Skill interdependency

altium-pcb-placement/scripts/connectivity_matrix.py imports net_erc.py from altium-schematic-review via a sibling-folder relative path. Install those two together.

Requirements

Verified combination

This is what was actually run here. Other versions are not known to be broken — if one is, please open an issue.

Altium Designer

Windows. Any step that only reads or writes files works with Altium closed. Coordinate injection, screenshots, and live library queries need it running.

Python 3.12 + altium_monkey

The scripts parse Altium files (.SchDoc .PcbDoc .PcbLib .SchLib) directly with altium_monkey. That package requires Python <3.13, so keep a separate 3.12 venv. The commands are in install step 2.

The scripts call that venv's python.exe by full path. The skill bodies write it as just python, so do not assume the python on your PATH is the right one.

pymupdf is for measuring datasheets and 2D drawings.

MCP: altium-mcp

Drives a running Altium. Needed for coordinate injection (place_components), screenshots, and live library queries. Without it, everything that touches files still works.

git clone https://github.com/coffeenmusic/altium-mcp.git C:\tools\altium-mcp

claude mcp add altium-mcp --scope user -- `
    C:\tools\edatools\Scripts\python.exe C:\tools\altium-mcp\start_server.py

On first call the server bootstraps its own venv and installs a script project into Altium. Check registration with claude mcp list, then ask Claude to call get_server_status.

Its README documents only the Claude Desktop route (a .dxt extension). Claude Code attaches it with claude mcp add, as above.

MCP: pcbparts (optional)

Part specs and stock (jlc_search), general design rules (get_design_rules). Hosted, so nothing to install.

claude mcp add --transport http pcbparts --scope user https://pcbparts.dev/mcp

Without it, find the same information in datasheets or on the web with WebSearch / WebFetch, which ship with Claude Code.

Do not run eda-agent alongside altium-mcp

Altium has exactly one global scripting slot. eda-agent needs to start its own polling loop inside Altium, and starting it kills the altium-mcp bridge.

The 3D model section of altium-library has two optional steps that use eda-agent tools (lib_extract_cse_zip, lib_easyeda_import). To use those, stop altium-mcp, run eda-agent, then switch back. Both steps have manual alternatives.

Using them

Skills trigger on their own. You do not name them — just say what you want to do, and Claude picks the skill from its description.

# altium-library
"make a footprint and symbol for this connector"     (attach the datasheet PDF)
"is this part already in the library?"
"verify the footprint I made against the drawing"

# altium-schematic-review
"review this schematic"
"any unconnected pins?"
"is any component missing a footprint?"

# altium-pcb-placement
"schematic is done, let's start the PCB"
"how big does the board need to be?"
"which way should this socket face?"

What a skill changes is not your input but how Claude works — measure before drawing, read the datasheet before calling a pin a defect, show a 1:1 plan before touching the PcbDoc.

What a session looks like

A plan drawing looks like this. The image below is altium-pcb-placement/examples/plan.example.json rendered with plan_svg.py — you can run it yourself.

Placement actually proceeds like this:

1. Extract the connection matrix from the schematic   who connects to whom
2. Measure part dimensions from the library           never draw from nominal values
3. Derive board size by accumulating each axis        computed, not "about 100x100"
4. Decide main IC rotation from pin-to-side mapping   four options, with scores
5. Show a 1:1 plan drawing (SVG/PNG)                  <- 2-4 rounds here is normal
6. On approval, inject coordinates into the PcbDoc
7. Run overlap and out-of-board checks

Connectors, sockets and main ICs are placed with a stated reason. Resistors and capacitors are only gathered near their owning IC without overlapping — you place them finally. Where they belong is decided by routing intent, and encoding that as a rule costs more than it saves.

Two things it asks of you

• Save in Altium before any file-parsing step. The scripts read the file on disk. If Altium holds unsaved edits, you get answers about an old version
• Nothing is injected until you approve. Redrawing the plan is cheap and editing the PcbDoc is not. 2-4 rounds on the drawing is normal

What is actually in here

Each skill is SKILL.md (the procedure) + references/ (trap detail) + scripts/ (runnable tools).

The 16 scripts

All of them run without Altium, because they parse the files with altium_monkey. Claude calls them for you, but you can run them yourself — they all take --help.

altium-library/scripts/

altium-schematic-review/scripts/

altium-pcb-placement/scripts/

Example — deciding connector rotation. python below is the venv python.exe from install step 2, called by full path. The script prints its column headers in Korean.

> python connector_facing.py board.SchDoc --libs C:\libs

des  개구부 돌출 mm     상변  하변  좌변  우변   풋프린트
J1   -Y       9.06      180    0   270    90   RJ45_J1B1211CCD
J2   -Y       2.21      180    0   270    90   USB-C_16P

숫자 = 그 변에 놓을 때 줘야 할 rotation (반시계 도).

des  opening  protrude mm   top  bottom  left  right   footprint

Read it as: to put J1 on the top edge, rotate it 180°. No datasheet lookup required.

Reference documents (references/)

Most of what was expensive to learn lives here — roughly 1,400 lines of "this is how it breaks, and this is how you notice".

What works without Altium

A placement plan for an outside PCB design house can be produced with no Altium at all — the schematic and libraries (or datasheets) are enough.

When it does not work

Contributing

Issues and PRs welcome. Two rules keep this useful.

• Write rules, backed by measured numbers. Do not narrate what went wrong. QFN32 body 4.00 -> actual footprint 7.05x7.00 is the information
• No specific chip or board names, and no values from one design. These are general-purpose skills; the verdict comes from the datasheet each time

License

MIT