diff --git a/README.md b/README.md
index d41c059..a97bff6 100644
--- a/README.md
+++ b/README.md
@@ -78,6 +78,10 @@ Run `feather sync` to synchronize all local data with the server. The synchroniz
 
 If you don't want to bother running `feather sync` manually, you can also start the Feather update daemon using `feather daemon`. The daemon will periodically call `sync-up` (by default every minute) and `sync-down` (by default every 15 minutes) for as long as it runs.
 
+#### If you are offline
+
+Nothing change, but all the synchronization commands will wait until the server become reachable again.
+
 ### Configuration
 
 Feather will try to load the configuration from the file `config.toml` by default. A lot of things can be configured, see [the default configuration file](src/feather/config.default.toml) for details. Most configuration options can also be set using environment variables - this is also detailed in the default configuration file ([here's another link if your mouse is too far from the previous one](src/feather/config.default.toml)).
@@ -161,7 +165,6 @@ before publishing:
 - [ ] Share the fun somewhere
 - [ ] Test with FreshRSS
     - [ ] Feed & category order for googlereader ??
-- [ ] Detect offline mode
 
 "i'll look into it later":
 
diff --git a/src/feather/client.py b/src/feather/client.py
index f340d78..9a8b236 100644
--- a/src/feather/client.py
+++ b/src/feather/client.py
@@ -12,6 +12,8 @@ from feather.data import Article, ArticleId, Category
 
 
 class ClientSession(ABC):
+    """Represent a client session with a RSS reader server. All operations will block indefinitely when waiting for the network."""
+
     @abstractmethod
     def __init__(self, config: Config):
         self.config: Config = config