Making mods

Making mods

A mod is a folder with a mod.json, signed with your own key. Everything a mod does is declared there, shown to the owner before it applies, and undone when it's turned off or removed. In the repository:

• docs/mod-reference.md: the full mod.json reference by topic. Already have a Gen5W package? tools/mod-draft.py drafts a mod.json from it so you can offer a mod alongside it.
• mods/examples/: working examples (hooks, a background service, a side panel page with readings, a test mod using buttons, projection and commands).
• docs/vehicle-commands.md: the car commands and their limits.
• docs/micom-map.md: mapping new car data.
• docs/api-plan.md: what each community project uses and what's planned.

Packaging: tools/mkmodpkg.sh <mod folder> <your key> (make a key once with java -cp out/engine-host hmgapi.engine.Signing keygen <file>). Keep the key safe: only packages signed with it update your mod.

Scripts on the head unit

The head unit's shell is mksh with a small toolbox: no sed, tr, awk, head, tail or busybox. See the mod reference for what there is, and run tools/check-scripts.sh <your mod> before packaging. HMG-API warns at install when a script calls a command the unit doesn't have.