🔌 v0.18.2 is out — 25% less nets unrouted, 3× fewer real DRC errors, half the memory on big boards

[drandyhaas]

Hey everyone! 👋

New release — v0.18.2. Where 0.18.0 made the router honest about your netclass clearances, 0.18.2 is about finishing more of your board — and being honest about the rest. Across our 75-board stress corpus this release completes 25% more of the previously-unfinished nets (329 → 247 incomplete), cuts real DRC violations on routed copper by more than 3× (123 → 39), and routes large sparse boards (looking at you, split keyboards) in roughly half the memory.

📦 How to get it: download KiCadRoutingTools-0.18.2.zip from the Releases page, then in KiCad open Plugin and Content Manager → Install from File… and pick that zip. Prebuilt router binaries for Linux/macOS/Windows are on the release too — python build_router.py fetches them automatically, no Rust toolchain needed.

🔌 More nets actually finish now

A stack of connectivity fixes, all on by default:

• Nothing gets silently lost anymore. Previously, a net that was ripped up mid-route and couldn't be re-routed could ship with zero copper — and worse, the final report sometimes graded it "fine". Now every rip is tracked: the router restores the original copper first (collision-checked), re-routes on top of it, and anything still broken is reported honestly as a failure with its history. A new coverage gate guarantees every disturbed net is either routed or owned in the output report — never silently dropped.
• Plane connections can't fake success. Plane repair now verifies against the plane's true connected component — a pad can no longer "connect" to a floating island of copper and count as done. On one 6-layer test board this alone took the GND net (404 pads) from two disconnected pieces to fully connected.
• Deferred differential pairs get finished in-run. When a pair can't be coupled-routed, both members now get a single-ended attempt right away, with per-member results in the report — no more one-legged pairs.
• Multipoint nets can split across layers intelligently. When no single layer works for every stub of a 3+-pad net, the router now assigns stubs per-cluster to the fewest layers that fit, instead of giving up.
• Net-tie footprints (Kelvin shunts, shorted jumpers) are understood end-to-end — the router routes through the tie pad the way the part intends, and DRC checking accepts the designed contact instead of flagging it.
• Failed nets get more rescue attempts: finer vias from your fab's ladder, scoped rip-up of blocking pre-existing copper, and a smarter final reconciliation round.

🧷 A manufacturability class you couldn't see before

We found (and fixed) a subtle hazard: a track could terminate on the corner of a pad — electrically connected, DRC-clean, but joined only through a copper sliver thinner than your minimum track width. That joint can etch open at the fab. 0.18.2 both detects this class (check_weird + KiCad's own connection_width check in our grading) and repairs it during cleanup by adding a short, clearance-checked connector into the pad — your routed track is never moved.

Also in the correctness bucket: custom pads with stroked primitives (rings, complex RF pads) now resolve to their true copper size (they were under-modeled by the stroke width), and a rescue-pass edge case that could drop a via on copper it couldn't see is fenced off for good.

🧠 Half the memory on big sparse boards

The Rust router (now 0.18.2) stores all permanent board geometry — edges, cutouts, everything immutable — in a compact bitmap instead of per-cell hash maps. Obstacle-map memory drops ~60–66%, and the worst case in our corpus (a split keyboard whose fine-grid retry previously ballooned past 8 GB and died) now completes its whole chain in under 5 GB. Routing results are bit-for-bit identical — we verified down to the exact A* iteration counts. A memory-allocator tweak also makes long runs return freed memory to the OS promptly, and the KiCad-oracle connectivity check that could take 10+ minutes on some boards now takes seconds.

🔎 Better failure reporting

When something doesn't route, the JSON summary now tells you why, per net and per diff pair: the failure stage, a reason code (congestion, no escape path, pose-router failure, …), which copper blocked it, and what the rescue/reconciliation passes tried. If you use the AI planning tab or the /diagnose-routing-failures skill, they consume all of this automatically.

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A note on honesty, continued: 0.18.0's "no rewritten design rules" policy means KiCad DRC now shows real rule violations on boards that were planned with a single flat clearance tighter than their netclasses — those were always there, just hidden before. The fix is re-planning those boards with per-class clearances (the AI planning tab's tune mode does this); the router itself already respects your classes. And on extremely saturated boards, finishing deferred pair members early can occasionally trade away a coupled route — we track that as a known follow-up.

As always, bug reports and feedback are hugely welcome — open an issue or just reply here. Happy routing! 🎉

[edgehero]

it really seems like you never sleep and make improvements that normally take months in days 🥇

[drandyhaas]

Fable doesn't get tired, it just runs out of usage. :)