Hardware CI/CD

Hardware-as-code (see Programmatic CAD) made it sane to commit CAD/PCB sources to git. The next step is treating them like software: PR previews of rendered parts, automated DRC, BOM diffs, generated G-code artifacts. Tooling is younger than software CI but the pieces exist in 2026.

Git-friendly source formats

• ★ STEP (AP242) — text-ish ASCII; diffable in principle, ugly in practice. The default mechanical interchange format.
• ★ .kicad_pcb / .kicad_sch (KiCad 7+/8+) — newline-delimited s-expressions; very git-friendly diffs.
• CadQuery / Build123d / OpenSCAD source — pure text, perfect diffs.
• .ato (Atopile) / tscircuit JSX — text, diffable, type-checkable.
• .f3d / .SLDPRT / .ipt / .prt (Fusion / SolidWorks / Inventor / Creo) — binary; commit STEP exports alongside.
• 3MF — zipped XML; viewable as a project artifact, not great as the source of truth.

CI for code-CAD

• ★ GitHub Actions + CadQuery / Build123d — run a script in CI, output STL / STEP / 3MF on every PR. The standard 2026 hobby pipeline.
• ★ GitHub Actions + OpenSCAD CLI — openscad -o out.stl input.scad in a workflow. Trivial and rock-solid.
• GitLab CI / Forgejo Actions — same pattern, different host.
• build-cad-on-ci community templates — composite actions for KiCad, FreeCAD, OpenSCAD, CadQuery on GitHub Marketplace.

PCB / EE CI

• ★ KiBot — open source; declarative YAML pipeline for KiCad — generate gerbers, BOM, 3D renders, fabrication outputs in CI. The de-facto KiCad CI tool.
• kicad-cli (built into KiCad 8+) — official CLI for export, ERC, DRC; KiBot wraps it but you can also use it directly.
• InteractiveHtmlBom (iBOM) — generates a clickable HTML BOM for assembly; commonly run in CI.
• kicad-action / setup-kicad GitHub Actions — drop-in installers for KiCad in workflows.
• Atopile CI — ato build in GitHub Actions outputs KiCad project artifacts.

Diff & review for hardware

• ★ KiCad 8+ schematic & PCB diff — built-in visual diff between any two revs / branches.
• kicad-diff.py — older Python tool for visual KiCad diffs in CI.
• Plotty / FlatCAM — gerber visualizers, useful for fab-output review.
• STEP diff (visual) — no great FOSS option in 2026; common workaround is to render PNGs of two STEPs in CI and post-comment on the PR.
• OpenSCAD if-diff — community macro to render before/after.

Artifact hosting for PRs

• GitHub Releases / Artifacts — attach STL, STEP, 3MF, gerber zip per build.
• Cloudflare Pages / Netlify per-PR previews — host static viewer pages (e.g., model-viewer for STEP/glTF) for PR review.
• Manyfold / Fishtank (self-hosted) — push artifacts to a private model library (see Model Libraries).
• OSHWLab, EasyEDA, Flux.ai sharing pages — hosted PCB design preview links (Flux is paid pro tier).

DRC / ERC / lint for hardware

• ★ kicad-cli erc / drc — official lint, runnable in CI.
• freerouting — open-source autorouter; sometimes part of CI when iterating on layouts.
• KLC checker (KiCad Library Checker) — checks symbol/footprint compliance against KiCad library conventions.
• Atopile checks — type-checking + electrical-rule checks at compile time.

Project / multi-board builds

• Make / just / Taskfile / Nx — orchestrate multi-board, multi-part builds. Many hardware repos use a top-level justfile to invoke FreeCAD, OpenSCAD, KiCad, and CadQuery in one command.
• Reproducible builds via Nix / devcontainer — pinning FreeCAD / KiCad / OpenSCAD versions matters; community Nix flakes exist for all three.

Documentation as part of CI

• ★ Render galleries with model-viewer (see 3D / WebGL) — embed glTF / GLB exports in your README or docs site.
• Docusaurus / Fumadocs / mdBook + auto-generated screenshots — common for assembly-instruction docs.
• Bill-of-materials generation — CadQuery and KiCad both produce BOMs in CI; commit the diff into PRs.

Pick this if…

• CadQuery / OpenSCAD project, want per-PR STL artifacts: GitHub Actions + slicer CLI.
• KiCad project, want gerbers + BOM on every push: KiBot.
• Atopile project: ato build in CI; commit outputs to a separate branch.
• Want PR review with rendered images: screenshot step + bot comment, or per-PR static-site preview.
• Need DRC/ERC blocking on PRs: kicad-cli (KiCad) + KLC checker for libraries.
• Reproducibility matters: Nix flake or pinned devcontainer.