diff --git a/sedna_sdk/endpoints/users.py b/sedna_sdk/endpoints/users.py
index 8932f34..e100f84 100644
--- a/sedna_sdk/endpoints/users.py
+++ b/sedna_sdk/endpoints/users.py
@@ -2,5 +2,92 @@ class UsersAPI:
     def __init__(self, client):
         self.client = client
 
-    def list(self):
-        return self.client._request("GET", "/user")
\ No newline at end of file
+    def list(self, page_limit=None, page_offset=None, sso_email=None, **kwargs):
+        """
+        List users with optional filtering and pagination.
+
+        Args:
+            page_limit (int, optional): Number of results per page (defaults to 100)
+            page_offset (int, optional): Number of results to skip (defaults to 0)
+            sso_email (str, optional): Filter by SSO email address
+            **kwargs: Additional filter parameters
+
+        Returns:
+            List of user dictionaries
+        """
+        params = {}
+
+        # Pagination parameters
+        if page_limit is not None:
+            params['page[limit]'] = page_limit
+        if page_offset is not None:
+            params['page[offset]'] = page_offset
+
+        # Filter parameters
+        if sso_email is not None:
+            params['filter[user.ssoEmail]'] = str(sso_email)
+
+        # Handle any additional filter parameters passed via kwargs
+        for key, value in kwargs.items():
+            if value is not None:
+                params[key] = str(value)
+
+        return self.client._request("GET", "/user", params=params)
+
+    def subscribe_to_job_reference(self, user_id: str, job_reference_id: str) -> dict:
+        """
+        Subscribe a user to a job reference.
+
+        Args:
+            user_id: The user's ID
+            job_reference_id: The job reference ID
+
+        Returns:
+            Created subscription details
+        """
+        data = {
+            "data": [
+                {
+                    "id": job_reference_id,
+                    "type": "job-reference"
+                }
+            ]
+        }
+        endpoint = f"/user/{user_id}/relationships/job-reference"
+        return self.client._request("POST", endpoint, json=data)
+
+    def unsubscribe_from_job_reference(self, user_id: str, job_reference_id: str) -> bool:
+        """
+        Unsubscribe a user from a job reference.
+
+        Args:
+            user_id: The user's ID
+            job_reference_id: The job reference ID
+
+        Returns:
+            True if successful
+        """
+        data = {
+            "data": [
+                {
+                    "id": job_reference_id,
+                    "type": "job-reference"
+                }
+            ]
+        }
+        endpoint = f"/user/{user_id}/relationships/job-reference"
+        self.client._request("DELETE", endpoint, json=data)
+        return True
+
+    def list_job_reference_subscriptions(self, user_id: str) -> list:
+        """
+        List all job reference subscriptions for a user.
+
+        Args:
+            user_id: The user's ID
+
+        Returns:
+            List of job reference relationships
+        """
+        endpoint = f"/user/{user_id}/relationships/job-reference"
+        return self.client._request("GET", endpoint)
diff --git a/sedna_sdk/sedna_client.py b/sedna_sdk/sedna_client.py
index 1ef75f2..d3500de 100644
--- a/sedna_sdk/sedna_client.py
+++ b/sedna_sdk/sedna_client.py
@@ -14,7 +14,10 @@ def __init__(self, status_code, message):
 
 class SednaClient:
     def __init__(self, subdomain, client_id, client_secret):
-        self.base_url = f"https://{subdomain}.sednanetwork.com/platform/2019-01-01"
+        if subdomain.startswith('http://') or subdomain.startswith('https://'):
+            self.base_url = subdomain.rstrip('/')
+        else:
+            self.base_url = f"https://{subdomain}.sednanetwork.com/platform/2019-01-01"
         credentials = f"{client_id}:{client_secret}"
         encoded = base64.b64encode(credentials.encode()).decode()
         self.headers = {
@@ -29,6 +32,9 @@ def __init__(self, subdomain, client_id, client_secret):
         self.comments = CommentsAPI(self)
         self.job_references = JobReferencesAPI(self)
 
+    def set_base_url(self, base_url):
+        self.base_url = base_url.rstrip('/')
+
     def _request(self, method, endpoint, **kwargs):
         url = f"{self.base_url}{endpoint}"
         response = requests.request(method, url, headers=self.headers, **kwargs)
@@ -37,4 +43,4 @@ def _request(self, method, endpoint, **kwargs):
 
         if response.content:
             return response.json()
-        return None
\ No newline at end of file
+        return None