Headless access

JustWrite’s server can run on its own, without the desktop window. Point a browser at it and you get the full app — same projects, same AI, no desktop install on that machine.

That’s useful when you want to write from a laptop or tablet while your books and your local AI models stay on one machine, or when you keep the app running on a home server and just open a tab.

Opening JustWrite in a browser

Under Settings → Server, the Headless access card shows the address the server is hosting the app at, with a Copy button. Paste it into any browser on the same machine and JustWrite loads.

The same section carries Keep server running after the app closes: with it on, closing the window hides JustWrite to the system tray and the server keeps serving — left-click the tray icon to bring the window back. The tray menu carries 📺 Show / 🔵 Hide window, ▶️ Start / ⏹ Stop / 🔄 Restart server, ⚙️ Open settings, 📋 Copy server URL (copies and confirms), 📜 Open log file, ℹ️ About, and 🚪 Quit — which stops the server too. With the switch off, closing the window stops everything.

By default that’s http://127.0.0.1:17495/ — which only accepts connections from the machine it’s running on. To reach it from another device, see Running the server yourself below.

Several windows at once. The desktop window and any browser tabs on the same server all show the same books. A change made in one shows up in the others within a few seconds, but not while you’re typing there or a dialog is open: it waits until you click out of the text. Restoring a backup or resetting the workspace in one window reloads the others.

Running the server yourself

You don’t have to open the desktop app at all. On Windows the installer puts a command called justwrite-server beside JustWrite in the install folder. From that folder, run:

justwrite-server serve

It starts on 127.0.0.1:17495 and prints the address to open. It is the same server the desktop app runs, on the same data folder — only without the window.

On macOS and Linux the command is justwrite-server too: on Linux it sits beside the justwrite program (for the AppImage, run the AppImage with --appimage-extract first; the command is then in the squashfs-root folder it makes), and on macOS it is inside the app, in JustWrite.app/Contents/Resources. From a copy of the source code, npm run server does it for you (options go after --).

Three options let you change that:

• --host — which addresses to accept connections on. Use --host 0.0.0.0 to allow other devices on your network. Read the next section first.
• --port — the port number, if 17495 is taken.
• --data-dir — which folder to read your work from (see Storage & engine).

For example, to serve your books to the rest of your home network:

justwrite-server serve --host 0.0.0.0

Leave the desktop app closed while doing this — both use the same port.

Behind a reverse proxy

The server answers only to this computer’s own names — localhost, its IP addresses and its computer name — so a web page can’t trick your browser into reaching it under another name. If you put it behind a reverse proxy on the same computer (nginx, Caddy) that serves it under a public name, set the environment variable JUSTWRITE_ALLOWED_HOSTS to that name before starting the server, for example JUSTWRITE_ALLOWED_HOSTS=write.example.com (several names are separated by commas). Without it, requests for that name are refused.

API access (bearer tokens)

The API access card, also under Settings → Server, controls who may call JustWrite’s API.

It is off by default, which is the right setting when the server only listens on your own machine — nothing else can reach it anyway.

The moment you serve beyond that machine with --host, turn it on. Click Generate for a random token (or paste your own), then Add token. After that every API request must carry that token, and anything without it is refused. Add as many tokens as you like and remove any of them later.

Two things worth knowing:

• Connections from the machine itself skip the check, so the desktop app keeps working normally. If you’d rather require a token even there, switch on Require a token even on localhost: the window you switch it on in keeps one of your tokens, so it stays signed in.
• The app itself always loads. Tokens guard the API, not the page — so a browser can always reach JustWrite and sign in: on another computer the page asks for an access token; paste one of yours and Connect. The browser keeps it for that server, so you sign in once.

Treat a token like a password: anyone holding one can read and change everything in your library.

Your tokens belong to this server, not to your data: resetting the workspace keeps them, restoring a backup keeps the ones the server has now, and a backup file never contains them.