diff --git a/centml/sdk/api.py b/centml/sdk/api.py
index 8e77548..1823dcb 100644
--- a/centml/sdk/api.py
+++ b/centml/sdk/api.py
@@ -134,6 +134,9 @@ def get_deployment_usage(
             step=step,
         ).values
 
+    def initialize_user(self):
+        return self._api.setup_stripe_customer_payments_setup_post()
+
 
 @contextmanager
 def get_centml_client():
diff --git a/centml/sdk/auth.py b/centml/sdk/auth.py
index 4547edf..01e85cb 100644
--- a/centml/sdk/auth.py
+++ b/centml/sdk/auth.py
@@ -58,19 +58,57 @@ def load_centml_cred():
 
 
 def get_centml_token():
+    # Always use fresh client credentials if available
+    if settings.CENTML_SERVICE_ACCOUNT_ID and settings.CENTML_SERVICE_ACCOUNT_SECRET:
+        access_token = authenticate_with_client_credentials()
+        if access_token is not None:
+            return access_token
+        else:
+            sys.exit(
+                "Could not authenticate with client credentials. Please check your service account configuration..."
+            )
+
+    # Fall back to stored credentials for interactive flows
     cred = load_centml_cred()
     if not cred:
         sys.exit("CentML credentials not found. Please login...")
     exp_time = int(jwt.decode(cred["access_token"], options={"verify_signature": False})["exp"])
 
     if time.time() >= exp_time - 100:
-        cred = refresh_centml_token(cred["refresh_token"])
-        if cred is None:
+        # Check if we have a refresh token (interactive flow)
+        refresh_token = cred.get("refresh_token")
+        if refresh_token is not None:
+            # Use refresh token for interactive authentication
+            cred = refresh_centml_token(cred["refresh_token"])
+            if cred is None:
+                sys.exit("Could not refresh credentials. Please login and try again...")
+        else:
             sys.exit("Could not refresh credentials. Please login and try again...")
 
     return cred["access_token"]
 
 
+def authenticate_with_client_credentials():
+    """
+    Authenticate using client credentials flow for service-to-service authentication.
+    Returns access token if successful, None otherwise.
+    """
+    if not settings.CENTML_SERVICE_ACCOUNT_ID or not settings.CENTML_SERVICE_ACCOUNT_SECRET:
+        return None
+
+    params = {
+        'grant_type': 'client_credentials',
+        'client_id': settings.CENTML_SERVICE_ACCOUNT_ID,
+        'client_secret': settings.CENTML_SERVICE_ACCOUNT_SECRET,
+        'scope': 'openid profile email',
+    }
+    response = requests.post(settings.CENTML_SERVICE_ACCOUNT_TOKEN_URL, data=params, timeout=10)
+    response.raise_for_status()
+    response_data = response.json()
+    access_token = response_data.get('access_token')
+    return access_token
+
+
 def remove_centml_cred():
     if os.path.exists(settings.CENTML_CRED_FILE_PATH):
         os.remove(settings.CENTML_CRED_FILE_PATH)
diff --git a/centml/sdk/config.py b/centml/sdk/config.py
index 3f935c0..3e8b6ea 100644
--- a/centml/sdk/config.py
+++ b/centml/sdk/config.py
@@ -1,4 +1,5 @@
 import os
+from typing import Optional
 from pathlib import Path
 from pydantic_settings import BaseSettings, SettingsConfigDict
 
@@ -16,5 +17,12 @@ class Config(BaseSettings):
 
     CENTML_WORKOS_CLIENT_ID: str = os.getenv("CENTML_WORKOS_CLIENT_ID", default="client_01JP5TWW2997MF8AYQXHJEGYR0")
 
+    # Long-term credentials - can be set via environment variables
+    CENTML_SERVICE_ACCOUNT_SECRET: Optional[str] = os.getenv("CENTML_SERVICE_ACCOUNT_SECRET", default=None)
+    CENTML_SERVICE_ACCOUNT_ID: Optional[str] = os.getenv("CENTML_SERVICE_ACCOUNT_ID", default=None)
+    CENTML_SERVICE_ACCOUNT_TOKEN_URL: str = os.getenv(
+        "CENTML_SERVICE_ACCOUNT_TOKEN_URL", default="https://signin.centml.com/oauth2/token"
+    )
+
 
 settings = Config()
diff --git a/setup.py b/setup.py
index f49fc7f..75d7d65 100644
--- a/setup.py
+++ b/setup.py
@@ -11,7 +11,7 @@
 
 setup(
     name='centml',
-    version='0.4.4',
+    version='0.4.5',
     packages=find_packages(),
     python_requires=">=3.10",
     long_description=open('README.md').read(),