Apex Harness Editor

Design harnesses on your own machine

Apex Harness Editor is a wire harness design tool that runs fully offline. Your harness is a plain-text file on your own disk — no cloud account, no sync, no subscription. Open it, work on it, own it. It keeps working whether or not we do.

One file, four views

Schematic, layout, connection table and parts list are four views of the same file. Change a wire in one and it changes everywhere. The format is diffable, so every edit is tracked in version control exactly like code — you can see what changed between revisions, line by line.

Output you can actually build from

The parts view gives you real part numbers, so what comes out is something you can order and build, not just a pretty diagram. Print it, export a PDF, or hand the connection table to whoever's crimping.

Built to travel with you

Already using another tool? Apex Harness Editor opens existing harness files, so you can bring your work across and drop the subscription without losing anything.

Pricing

Free for personal and hobby use — no feature limits, no time limit. Build all you want. Personal exports carry a small "Designed with Apex Harness Editor" mark.

€50 commercial license — one payment. Covers paid work, removes the mark, and it's yours to keep. Buy it once, no recurring fee.

Pro — coming soon. Unlimited sheets, multiplayer design, and advanced documentation views for whole-vehicle and multi-subsystem builds. Personal and commercial buyers upgrade for the difference, never a re-buy.

Who's behind it

Apex Harness Editor is built by Apex Control Innovations — we build transmission control electronics for engine swaps, restomods and motorsport, including IOcan, which runs OEM ZF 8HP and DCT gearboxes in any swap. We wire cars for a living, so we built the tool we wanted to use.