WilhelmSK Documentation (SignalK plugin)

A SignalK node-server plugin that serves the WilhelmSK documentation site directly from your boat's SignalK server, so the app's in-app help works offline.

WilhelmSK is the marine instrument display app for iOS, iPadOS, and watchOS. Install this plugin and the app can offer in-app help straight from your own SignalK server — no internet connection required once it's on the boat.

What it does

• Serves the bundled MkDocs documentation site at /signalk-wilhelmsk-docs/.

• Works fully offline — the entire docs site ships with the plugin.

• Serves a small version/info file at /signalk-wilhelmsk-docs/info.json:

  {
    "id": "signalk-wilhelmsk-docs",
    "version": "0.1.4",
    "docsPath": "/signalk-wilhelmsk-docs/"
  }

  It reports the installed plugin version and the docs path. The WilhelmSK app verifies the docs are reachable by probing the docs root before pointing its in-app help at http://<host>:<port>/signalk-wilhelmsk-docs/.

  Why a static file and not a plugin endpoint: SignalK mounts registerWithRouter routes under /plugins/*, which the server's security middleware gates behind authentication. Keeping info.json (and the docs themselves) on the open static route means they're reachable without a token. info.json is generated from the plugin version by scripts/gen-info.js during npm run build-docs.

Install

From the SignalK App Store

In the SignalK server admin UI, open Appstore → Available and look for WilhelmSK Documentation (the WilhelmSK app icon, by David Lewis). Searching the list for wilhelm or documentation will find it. The entry shows the short description — "Serves the WilhelmSK app documentation from your SignalK server, so in-app help and direct browser access work without an internet connection. Open it from the Webapps menu or browse to /signalk-wilhelmsk-docs/." — a version number, and an Install button.

Click Install, then restart the server when the admin UI prompts you. There are no configuration options — the docs start serving immediately, and the plugin appears afterward under Appstore → Installed.

Manually (development)

cd ~/.signalk/node_modules
npm install /path/to/signalk-wilhelmsk-docs/plugin
# or symlink for local development:
ln -s /path/to/signalk-wilhelmsk-docs/plugin signalk-wilhelmsk-docs

Restart the SignalK server, then enable WilhelmSK Documentation under Server → Plugin Config.

Verify

curl http://localhost:3000/signalk-wilhelmsk-docs/info.json
curl -I http://localhost:3000/signalk-wilhelmsk-docs/

Reading the docs

There are two ways to get to the documentation, and the first one needs nothing but a web browser — the WilhelmSK app is not required.

Directly in a browser (no app needed)

Once the plugin is installed, the full documentation site is live on your server. From any phone, tablet, or laptop on the boat's network, open:

http://<your-signalk-host>:3000/signalk-wilhelmsk-docs/

(substitute your server's address — e.g. http://signalk.local:3000/signalk-wilhelmsk-docs/ or its LAN IP). It also shows up in the SignalK admin UI under the Webapps menu as a launchable web app. Because it's served as a standard static site, it works on the boat with no internet connection, and it does not depend on the plugin being "enabled" in plugin config — installing the package is enough.

From inside WilhelmSK

The WilhelmSK iOS/iPadOS app can open this same server-hosted copy from Settings → Help / Documentation with the source set to SignalK Server, so the help is available in-app and offline. (This relies on the app build that includes the in-app documentation-source picker; until that ships, use the browser method above — it works with any version.)

Size

The plugin bundles the entire documentation site (so it works without internet access on the boat). Everything ships inside the package — installing it adds nothing to node_modules beyond the plugin's own folder, because it has no runtime dependencies. So the installed footprint below is the whole cost:

| What | Size | |------|------| | Download (npm tarball, gzipped) | ~670 KB | | Installed on disk | ~2.8 MB (54 files) | | Extra node_modules dependencies | none |

Almost all of the on-disk size is the Material theme's bundled assets (fonts, icons, JS, CSS — about 2.5 MB) plus the rendered HTML pages; the plugin code itself is only a few KB. On a Raspberry Pi-class SignalK server — where the OS, Node, and signalk-server already account for a few GB — under 3 MB of docs is negligible and will fit comfortably on any install that runs SignalK at all.

Documentation content

The public/ directory holds the built MkDocs site. It is generated from the docs/ sources at the repository root via mkdocs build -d plugin/public/ (see the repo root README.md / npm run build-docs).

License

MIT © 2026 David Lewis