watchtower documentation

watchtower.rst

@@ -2,16 +2,59 @@ How to setup a watchtower
 =========================
 
 This tutorial will show you how to configure your Electrum daemon as a
-watchtower for your lightning wallet.  It is written for Electrum 4.0
-(currently in development_)
+watchtower for your lightning wallet.  It is written for Electrum 4.0.
 
-.. _development:
-    https://github.com/spesmilo/electrum#development-version-git-clone
 
-Add your SSL certificate to Electrum
+Local and remote watchtower
+---------------------------
+
+There are two ways a watchtower can be configured in Electrum: Local
+or Remote.
+
+A local watchtower runs in the same process as your Electrum client,
+and can be activated in the preferences dialog of the Qt GUI. A local
+watchtower creates a database of pre-signed breach remedy
+transactions, and it watches the funding addresses of your
+channels. When your lightning wallet is open, breach remedy
+transactions will be signed and added to the watchtower database.
+Once you your wallet is closed, assuming Electrum is still running,
+the local watchtower will watch your channels, and it will broadcast
+pre-signed breach remedy transactions if needed.
+
+A remote watchtower is a separate Electrum process, that runs on
+another computer. To setup a remote watchtower, you need to configure
+an Electrum daemon, and to enter its URL in your preferences.
+
+
+How to configure a local watchtower
 ------------------------------------
 
-To protect against MITM attacks, add a SSL certificate:
+In your preferences, check 'Run a local watchtower'
+
+.. image:: png/watchtower_settings.png
+
+
+The second option ensures that Electrum keeps running on your computer
+after you have closed your wallet file. If you click it, the Electrum
+icon should persist in your taskbar after you have closed all your
+Electrum windows.
+
+
+If you have open channels and a local watchtower, Electrum will
+populate the watchtower database.  You can view the database size and
+number of transactions per channel if you open the watchtower window:
+
+.. image:: png/watchtower_window.png
+
+
+How to configure a remote watchtower
+------------------------------------
+
+You want to run your watchtower on a machine that is regularly
+connected to the internet.
+
+First install Electrum, and add a SSL certificate to your Electrum
+configuration:
 
 .. code-block:: bash
 
@@ -21,10 +64,7 @@ To protect against MITM attacks, add a SSL certificate:
 For details see `How to add SSL <ssl.html>`_
 
 
-Configure your Watchtower
--------------------------
-
-Configure your watchtower address and password:
+Second, configure your watchtower with an address, username and password:
 
 .. code-block:: bash
 
@@ -44,6 +84,9 @@ The watchtower database contains presigned transactions, and is in
 ~/.electrum/watchtower_db If you open the GUI you can see hown many
 channels and transactions are in the database.
 
+Note that the daemon does not need to contain a wallet, nor to have
+Lightning enabled; the watchtower is only about watching onchain
+addresses and broadcasting onchain transactions.
 
 Configure the watchtower in your client
 ---------------------------------------