diff --git a/README.md b/README.md
index 99b7639..6dbec8a 100644
--- a/README.md
+++ b/README.md
@@ -17,7 +17,7 @@
 - Communication over TCP and/or websocket, including support for SSL/TLS
 - Support QoS 0, QoS 1 and QoS 2 messages flow
 - Client auto-reconnection on network lost
-- Functionality expansion; plugins included: authentication and `$SYS` topic publishing
+- Custom functionality expansion; plugins included: authentication, `$SYS` topic publishing, session persistence
 
 ## Installation
 
diff --git a/amqtt/plugins/persistence.py b/amqtt/plugins/persistence.py
index c24ad70..a23737a 100644
--- a/amqtt/plugins/persistence.py
+++ b/amqtt/plugins/persistence.py
@@ -111,6 +111,14 @@ class StoredMessage(Base):
 
 
 class SessionDBPlugin(BasePlugin[BrokerContext]):
+    """Plugin to store session information and retained topic messages in the event that the broker terminates abnormally.
+
+    Configuration:
+        - file *(string)* path & filename to store the session db. default: `amqtt.db`
+        - clear_on_shutdown *(bool)* if the broker shutdowns down normally, don't retain any information. default: `True`
+
+    """
+
     def __init__(self, context: BrokerContext) -> None:
         super().__init__(context)
 
@@ -298,7 +306,6 @@ class SessionDBPlugin(BasePlugin[BrokerContext]):
         """Configuration variables."""
 
         file: str | Path = "amqtt.db"
-        retain_interval: int = 5
         clear_on_shutdown: bool = True
 
         def __post_init__(self) -> None:
diff --git a/docs/packaged_plugins.md b/docs/packaged_plugins.md
index bc43d3a..74a2207 100644
--- a/docs/packaged_plugins.md
+++ b/docs/packaged_plugins.md
@@ -47,8 +47,6 @@ By default, the `PacketLoggerPlugin` is  activated  and configured for the clien
 
 ```yaml
 plugins:
-  .
-  .
   amqtt.plugins.authentication.AnonymousAuthPlugin:
       allow_anonymous: false
 ```
@@ -242,3 +240,25 @@ and `on_mqtt_packet_received`.
 plugins:
   amqtt.plugins.logging_amqtt.PacketLoggerPlugin:
 ```
+
+
+### Session Persistence
+
+`amqtt.plugins.persistence.SessionDBPlugin`
+
+Plugin to store session information and retained topic messages in the event that the broker terminates abnormally.
+
+**Configuration**
+
+- `file` - *(string)* path & filename to store the session db. default: `amqtt.db`
+- `clear_on_shutdown` *(bool)* if the broker shutdowns down normally, don't retain any information. default: `True`
+
+```yaml
+plugins:
+  amqtt.plugins.persistence.SessionDBPlugin:
+    file: 'amqtt.db'
+    clear_on_shutdown: True
+```
+
+
+
diff --git a/docs_web/index.md b/docs_web/index.md
index 8d4110d..3f933d6 100644
--- a/docs_web/index.md
+++ b/docs_web/index.md
@@ -10,7 +10,7 @@
 - Communication over TCP and/or websocket, including support for SSL/TLS
 - Support QoS 0, QoS 1 and QoS 2 messages flow
 - Client auto-reconnection on network lost
-- Functionality expansion; plugins included: authentication and `$SYS` topic publishing
+- Custom functionality expansion; plugins included: authentication, `$SYS` topic publishing, session persistence
 
 ## Installation
 
diff --git a/tests/plugins/test_persistence.py b/tests/plugins/test_persistence.py
index 63d8a8c..7fab154 100644
--- a/tests/plugins/test_persistence.py
+++ b/tests/plugins/test_persistence.py
@@ -142,7 +142,7 @@ async def test_update_stored_session(db_file, broker_context, db_session_factory
 )"""
         await db.execute(sql)
         await db.commit()
-    
+
     await session_db_plugin.on_broker_client_subscribed(client_id='test_client_1', topic='my/topic', qos=2)
 
     # verify that the stored session has been updated with the new subscription