diff --git a/pocketoptionapi_async/client.py b/pocketoptionapi_async/client.py
index 6b2f59b..23fc41b 100644
--- a/pocketoptionapi_async/client.py
+++ b/pocketoptionapi_async/client.py
@@ -660,11 +660,16 @@ def _format_session_message(self) -> str:
         """Format session authentication message"""
         # Always create auth message from components using constructor parameters
         # This ensures is_demo parameter is respected regardless of SSID format
+        # Include all fields that the browser sends for full compatibility
+        # CRITICAL: Use 'sessionToken' (not 'session') to match browser format
         auth_data = {
-            "session": self.session_id,
+            "sessionToken": self.session_id,
             "isDemo": 1 if self.is_demo else 0,
-            "uid": self.uid,
+            "uid": str(self.uid),  # Browser sends uid as string
             "platform": self.platform,
+            "lang": "en",
+            "currentUrl": "cabinet",
+            "isChart": 1,
         }
 
         if self.is_fast_history:
@@ -682,7 +687,8 @@ def _parse_complete_ssid(self, ssid: str) -> None:
                 json_part = ssid[json_start:json_end]
                 data = json.loads(json_part)
 
-                self.session_id = data.get("session", "")
+                # Accept both 'session' and 'sessionToken' (browser uses sessionToken)
+                self.session_id = data.get("session", "") or data.get("sessionToken", "")
                 # Store original demo value from SSID, but don't override the constructor parameter
                 self._original_demo = bool(data.get("isDemo", 1))
                 # Keep the is_demo value from constructor - don't override it
diff --git a/tools/get_ssid.py b/tools/get_ssid.py
index cf0efb5..78cade2 100644
--- a/tools/get_ssid.py
+++ b/tools/get_ssid.py
@@ -67,9 +67,8 @@ def get_pocketoption_ssid():
         cabinet_base_url = "https://pocketoption.com/en/cabinet"
         target_cabinet_url = "https://pocketoption.com/en/cabinet/demo-quick-high-low/"
         # Regex to capture the entire "42[\"auth\",{...}]" string.
-        # This pattern is designed to be robust and capture the full authentication message,
-        # regardless of the specific content of the 'session' field (e.g., simple string or serialized PHP array).
-        ssid_pattern = r'(42\["auth",\{"session":"[^"]+","isDemo":\d+,"uid":\d+,"platform":\d+,"isFastHistory":(?:true|false)\}\])'
+        # Made more flexible to handle different auth message formats.
+        ssid_pattern = r'(42\["auth",\{[^\}]+\}\])'
 
         logger.info(f"Navigating to login page: {login_url}")
         driver.get(login_url)