Tiny routed

kiwrap — an AI-agent-facing wrapper over KiCad

Status: Phase 1c implemented — 2026-09-20. KiCad 11 (nightly) is the primary target (decision D16): a headless IPC backend on kicad-cli api-server gives structured, data-first feedback (D17) — board/schematic items, nets, connectivity, ratsnest — and authors schematics and boards (symbols, wires, labels, power, hierarchical sheets, annotation, footprint assignment, board setup, netlist sync, placement, zones, routing primitives) with file-tier and kicad-cli fallbacks on KiCad 10.0.x, 9 and 8. Phase 1c adds autorouting (kw_pcb_route_auto / kw_pcb_fix: Freerouting 2.4.1 under a managed JRE 25 over a Specctra DSN/SES round trip — kiwrap's own codec certified against KiCad's exporter/importer, the patched kicad-cli pcb export specctra / pcb import-ses on the fork build, mandatory refill + kicad-cli DRC as the judge), the JLCPCB fabrication profile (kw_fab_export(profile= "jlcpcb"), kw_fab_bom, kw_pcb_setup(preset=…)), intent (kw_intent, diffed by kw_sch_check) and the D5 reference board eval. An agent conversation over MCP stdio builds a two-sheet LDO + 555 blinker from nothing to gerbers — hand-routed and autorouted — with ERC 0 / parity 0 / DRC 0 on the 10.99 nightly (ipc11) and 10.0.6 (file) (tests/test_e2e_authoring.py), and the ESP32-S3 reference board (29 parts, 3 sheets, 2 layers) from kw_intent to a JLCPCB bundle with the grader green — ERC 0, intent diff empty, unrouted 0, must_fix 0 — on both (tests/test_e2e_reference_board.py; numbers below). A source-build bench of the fork carries the CLI/IPC additions listed in docs/UPSTREAM.md.

Phase 2 (integrated and verified end to end, 2026-09-20): the VS Code extension. extension/ (TypeScript, MIT, a private .vsix built by scripts/build_extension.ps1 into dist/) is an MCP client of its own kiwrap serve; it shows Live KiCad — the real, sandboxed stock KiCad editors (10.0.x / 10.99) streamed live into the .kicad_pcb / .kicad_sch tabs by the Rust helper helper/kiwrap-live.exe (Windows.Graphics.Capture, loopback + token). The user sees the agent's edits live; to edit by hand they raise KiCad (the tab's Raise KiCad button, a double-click) and work in the real window — decision D20: the live view with native interaction is the product, the cloaked/injecting modes measured in DISPLAY.md stay parked as experiments. Plus ERC/DRC in the Problems panel, a KiCad picker and a one-command Claude Code setup. The server side is the kw_live tool (a sandboxed GUI session whose API socket the ipc11 provider binds to) and the two-server model: the agent's own kiwrap serve finds the extension's session through its record and writes into the same window — measured in extension/test/e2e (12/12 in a real dev host): an agent's kw_pcb_place over a second MCP client repainted the live tab 431-474 ms after the call started (kw_pcb_place 870-979 ms via ipc11), Raise KiCad put the real pcbnew / eeschema in the foreground within ~0.9 s (GetForegroundWindow), on 10.99 and on 10.0.6. Details and the numbers: docs/EXTENSION.md (§9.1, §9.2), user guide extension/README.md, the measured display investigation docs/DISPLAY.md, screenshots docs/research/display/img/phase2-*.png.

kiwrap lets an AI agent (Claude Code inside VS Code; Windows only — decision D18) do end-to-end electronics development on KiCad — spec → schematic → ERC → board → placement → routing → DRC → fabrication files — as a wrapper over installed KiCad binaries so KiCad can be upgraded underneath (7 → 8 → 9 → 10 → 11).

Quick start (Windows)

git clone git@github.com:n3rd-bugs/kiwrap.git; cd kiwrap
.\scripts\bootstrap.ps1          # uv, deps, private JRE 25 + Freerouting into %LOCALAPPDATA%\kiwrap (Linux: scripts/bootstrap.sh)
uv run kiwrap env                # discovered KiCad installs + capability records
uv run pytest -q                 # ~5 min with four KiCads installed; ~1 min without KiCad
uv run kiwrap serve              # MCP server over stdio (Claude Code picks it up from .mcp.json)
.\scripts\build_extension.ps1     # VS Code extension + helper -> dist\kiwrap-<ver>.vsix (needs Node 24 + Rust stable-msvc)
code --install-extension .\dist\kiwrap-0.1.0.vsix   # then "kiwrap: Select KiCad", "kiwrap: Configure Claude Code"

Tools (34): kw_env, kw_project (create / status / retarget / upgrade_preview), kw_project_upgrade (the only conversion of a project to a newer KiCad file format; Claude Code asks the user on every call), kw_snapshot, kw_job, kw_help, kw_live (launch / attach / status / screenshot / detach / raise a sandboxed GUI KiCad the extension displays and the ipc11 provider writes into), kw_intent (declare nets / rails / interfaces; diffed against KiCad's netlist by kw_sch_check), kw_lib_search / kw_lib_info (FTS index over the sym-/fp-lib-tables), the schematic authoring tools kw_sch_add_symbol (absolute pin endpoints back), kw_sch_connect, kw_sch_add_item (power, PWR_FLAG, labels, sheets), kw_sch_edit, kw_sch_annotate, kw_sch_assign_footprints, the reads kw_sch_get (symbols with pin nets, wires, labels, hierarchy, netlist), kw_sch_stats, kw_sch_check (ERC + netlist), kw_sch_diff (KiCad 11), the board authoring tools kw_pcb_setup, kw_pcb_sync (KiCad's netlist, parity-checked), kw_pcb_place, kw_pcb_zones, kw_pcb_route (track / via primitives with per-net DRC deltas), kw_pcb_route_auto (Freerouting over DSN/SES, a background job with pass / unrouted progress), kw_pcb_fix (rip up the nets of must_fix violations and re-route them until DRC is clean), the reads kw_pcb_get (footprints, pads, tracks, vias, zones, nets, connectivity), kw_pcb_check (courtyard overlaps, off-board, unrouted / ratsnest), kw_pcb_drc, kw_fab_bom, kw_fab_export (generic or the JLCPCB profile: Protel gerbers, PTH/NPTH drills, corrected CPL, BOM, zip), and the secondary renders kw_sch_render / kw_pcb_render. Every tool names its provider (ipc11, file, cli, codec, cli:<v>+<patch>) and any degradation. The agent-facing protocol is in AGENTS.md and the skill in .claude/skills/kiwrap-flow/SKILL.md.

File formats and consent (D21, D24). A project runs on the installed KiCad that writes its files' own format. A write that would move the files to a newer format stops with E_FORMAT_UPGRADE_REQUIRED, whose data.upgrade_args are the arguments of kw_project_upgrade(project, from_kicad, to_kicad, files). That tool is published with _meta["anthropic/requiresUserInteraction"]: true, so Claude Code (2.1.199 and later) shows the user a permission card for every call, whatever the allow rules or permission mode (a headless session denies it); the VS Code extension's modal calls the same tool. The receipt records which gate and client approved the call, and its snapshot_before undoes the conversion. scripts/e2e_consent.py is the manual end-to-end checklist for that card (docs/VERIFICATION.md claim 13).

Phase 1c end-to-end numbers (2026-09-20)

Recorded by tests/test_e2e_reference_board.py and tests/test_e2e_authoring.py (each run writes <project>/.kiwrap/e2e-out.json and e2e-log.json with provider_used per call):

Unrouted is always KiCad's unconnected_items count after pcb drc --refill-zones --save-board, never Freerouting's own score. Pour order matters for the router: the B.Cu GND plane before routing, the F.Cu pour after (docs/ARCHITECTURE.md §8).

Read in this order

1. docs/ARCHITECTURE.md — the decision document: verified capability matrix, components, integration strategy per KiCad version, the in-KiCad-plugin and source-build decisions, tool catalog, roadmap, risks, §15 decisions, §16 what verification changed, §17 known gaps.
2. docs/DECISIONS.md — the 15 decisions taken on 2026-09-19 with alternatives and consequences, plus D16 (KiCad 11 first) and D17 (data-first feedback, upstream CLI/IPC expansion, source build).
3. docs/VERIFICATION.md — the 12 load-bearing claims (plus claim 13, D24's consent gate), each attacked by an empirical and a documentary verifier, with corrections.
4. CLAUDE.md — working conventions for anyone (human or agent) changing the code.
5. docs/research/ — nine research digests and the three competing proposals with judge reports; spikes/ — the experiment scripts that produced the evidence.
6. docs/dev/ — the KiCad source-build bench (executed), crash symbolication, upstream workflow; docs/LINUX.md — what the Linux CI job proves; docs/UPSTREAM.md — gap cards and the fork/patch workflow for the KiCad CLI/IPC additions.
7. docs/EXTENSION.md — the VS Code extension: processes, channels, security, the two-server model, live modes, keybinding policy; docs/DISPLAY.md — the measured display investigation behind it; extension/README.md — the user guide.

Layout

src/kiwrap/            single MIT distribution (src layout)
  platform/            Windows/Linux seam — the only place that inspects sys.platform
  installation.py      KiCadInstallation + discover()/find()   (registry, Program Files, PATH; Linux: apt/Flatpak/Snap/AppImage)
  capability.py        capability record per FULL semver, seeded from data/kicad_version_matrix.json + --help probes
  sandbox.py           sandboxed KICAD_CONFIG_HOME roots; the user's own KiCad config is read-only (tests assert its hash)
  formats/             zero-dependency: lossless CST, board/schematic models, geometry + analyses (overlaps, connectivity, ratsnest), parsers
  backends/cli/        kicad-cli adapters with the verified quirks (ERC JSON ×100, exit codes, .kicad_prl, out dirs, …) + structured exports
  backends/ipc/        KiCad 11 headless IPC sessions (kicad-python), mm-unit readers, connectivity queries, writes, T5 probe
  core/                MCP server, kw_* tools, receipts/teaching errors, stage machine + gates, locks, snapshots, jobs
conformance/           T1 CST round-trip, T2 file models vs KiCad, T4 kicad-cli help drift, T5 IPC handler snapshot, T6 quirks, T7 IPC writes + Specctra codec vs KiCad's DSN/SES, T8 writers vs KiCad + corpus
tests/                 unit + live tests (auto-skip without KiCad)
extension/             the VS Code extension (TypeScript, MIT): MCP client of `kiwrap serve`, Live KiCad tabs, Problems panel, Configure Claude Code
helper/                Rust workspace (MIT): kiwrap-live.exe, the Windows.Graphics.Capture + input helper the extension bundles
scripts/               bootstrap.ps1 / bootstrap.sh, build_extension.ps1 (-> dist/*.vsix), engines.json (pinned JRE/Freerouting), seed_config_root.py, ci/, dev/

Shape of the design (one paragraph)

One Python MCP server (kiwrap-core, kw_* tools) is the only agent contract; a thin TypeScript VS Code extension is a client of it (its own instance; the agent runs another, both sharing the storage home and the per-project lock), shows the sandboxed KiCad GUI that kw_live launched inside VS Code tabs through a Rust capture helper, and feeds ERC/DRC into the Problems panel; the KiWrap Connect KiCad plugin of the Phase-0 plan is not needed while kw_live owns the GUI it displays. On KiCad 11 the primary backend is the headless IPC API (kicad-cli api-server, driven through kicad-python): structured reads of every board and schematic item, connectivity, netlist and hierarchy, and writes as undoable commits. Underneath sits an in-house lossless s-expression engine that models boards and schematics on every version 7–11 (pin endpoints, courtyards, zone fills, connectivity, a ratsnest estimate verified against KiCad's own DRC) and is the only schematic path on ≤ 10. ERC/DRC/exports come exclusively from kicad-cli — KiCad is the judge. Routing will be Freerouting 2.4.1 over DSN/SES (managed JRE 25). Every tool answers in millimetres with its provider (ipc11, file, cli) and any degradation named; stage gates (ERC → sync → place → route → DRC → fab) are server-enforced. Where KiCad exposes no structured surface (ratsnest export, DRC/ERC over the API, headless jobs) the private fork n3rd-bugs/kicad-fork carries the additions until they are merged upstream.

Local environment this was verified on

Windows 11; KiCad 7.0.6, 8.0.9, 9.0.9, 10.0.6 and the 10.99 nightly (10.99.0-4083, KiCad 11 preview) side by side under C:\Program Files\KiCad, plus the registered source builds under C:\kiwrap-builds; Python 3.11 + uv; Node 24 LTS and Rust 1.95 stable-msvc (the extension build); VS Code 1.138; Java 17 on PATH (Freerouting 2.4.1 needs 25 → managed JRE); VS 2022 17.14 (MSVC 14.44) + vcpkg for the KiCad source bench; cdb from the Windows 10 SDK. Linux code paths exist behind the platform seam but are out of scope (D18).