kicad-layoutlisted

# Headless layout / autorouting Engine: `$(kx root)/kicad_lib/layout.py` (python API: PYTHONPATH=<repo>; any freerouting-*-linux-x64 in .tools is auto-detected, newest wins). Worked end-to-end example: `tests/test_layout.py` (scratch board with outline + 2 netted footprints → 9 routed segments). ## The chain layout.autoroute(pcb_in, pcb_out, passes=20) = dsn_export (pcbnew python in the KiCad flatpak: pcbnew.ExportSpecctraDSN — headless, verified 10.0) → route (.tools/freerouting-2.2.4-linux-x64/bin/freerouting, BUNDLED JRE — no system java; classic CLI -de in.dsn -do out.ses -mp N -da) → ses_import (pcbnew.ImportSpecctraSES + SaveBoard) Returns segment/via counts. Bootstrap if .tools missing: download freerouting-X-linux-x64.zip from github freerouting/freerouting releases, unzip into .tools/ (no root needed). ## Preconditions (or DSN export is meaningless) - Edge.Cuts outline present (closed). - Pads carry nets. Update-PCB-from-Schematic normally fills them; when building boards programmatically, append `(net "NAME")` to each pad — pcb format 20260206 (KiCad 10) keys nets BY NAME, no numeric id (old `(net 1 "N1")` style is normalized on import, harmless). - Placement matters more than the router: group by schematic function, decoupling caps adjacent, connectors at edges (rule canon). ## After routing — never skip 1. `kicad-cli pcb drc --severity-all` set-diff vs pre-route