diff --git a/aiotractive/api.py b/aiotractive/api.py
index e7d82c8..b502b1e 100644
--- a/aiotractive/api.py
+++ b/aiotractive/api.py
@@ -2,6 +2,7 @@
 
 import asyncio
 import json
+import time
 
 import aiohttp
 from aiohttp.client_exceptions import ClientResponseError
@@ -42,11 +43,11 @@ def __init__(  # pylint: disable=too-many-arguments
         self._auth_headers = None
 
     async def user_id(self):
-        await self._authenticate()
+        await self.authenticate()
         return self._user_credentials["user_id"]
 
     async def auth_headers(self):
-        await self._authenticate()
+        await self.authenticate()
         return {**self.BASE_HEADERS, **self._auth_headers}
 
     async def request(self, *args, **kwargs):
@@ -76,9 +77,12 @@ async def raw_request(self, uri, params=None, data=None, method="GET"):
                 return await response.json()
             return await response.read()
 
-    async def _authenticate(self):
+    async def authenticate(self):
         """Perform authenticateion."""
-        # TODO: update credentials if expired
+        if self._user_credentials is not None and self._user_credentials["expires_at"] - time.time() < 3600:
+            self._user_credentials = None
+            self._auth_headers = None
+
         if self._user_credentials is not None:
             return self._user_credentials
 
diff --git a/aiotractive/channel.py b/aiotractive/channel.py
index f3dc0d3..ed5e323 100644
--- a/aiotractive/channel.py
+++ b/aiotractive/channel.py
@@ -3,7 +3,7 @@
 import time
 from asyncio.exceptions import TimeoutError as AIOTimeoutError
 
-from .exceptions import DisconnectedError
+from .exceptions import DisconnectedError, TractiveError
 
 
 class Channel:
@@ -34,7 +34,7 @@ async def listen(self):
                 self._check_connection_task.cancel()
 
                 await self._check_connection_task
-                raise event["error"]
+                raise TractiveError() from event["error"]
 
             if event["type"] == "cancelled":
                 self._listen_task.cancel()
diff --git a/aiotractive/tractive.py b/aiotractive/tractive.py
index d59d6a5..81a2d29 100644
--- a/aiotractive/tractive.py
+++ b/aiotractive/tractive.py
@@ -11,6 +11,9 @@ def __init__(self, *args, **kwargs):
         """Initialize the client."""
         self._api = API(*args, **kwargs)
 
+    async def authenticate(self):
+        return await self._api.authenticate()
+
     async def trackers(self):
         trackers = await self._api.request(f"user/{await self._api.user_id()}/trackers")
         return [Tracker(self._api, t) for t in trackers]
diff --git a/setup.py b/setup.py
index fac5d4c..d7c700c 100644
--- a/setup.py
+++ b/setup.py
@@ -8,7 +8,7 @@
 
 setup(
     name="aiotractive",
-    version="0.3.0",
+    version="0.4.0",
     author="Gleb Sinyavskiy",
     author_email="zhulik.gleb@gmail.com",
     description="Asynchronous Python client for the Tractive REST API",