tools/meow_yaml.js is a browser-only bundle of the ISC-licensed yaml document API. It retains comments, aliases and unrelated configuration while LuCI edits its managed keys. The bundled file and meow_yaml.LICENSE ship in the LuCI package; npm is not needed on OpenWrt.

Regenerate from pinned dependencies:

cd openwrt/luci-app-meow
npm ci
npm run build

The Settings map's save callback runs after LuCI parses form values and before UCI is saved. YAML validation/upload failures reject that save. If UCI saving subsequently fails, the callback's rollback restores the previous YAML unless another writer has changed it. The separate Configuration editor applies the same transformation before validating imported YAML.