diff --git a/python_gpt_po/models/enums.py b/python_gpt_po/models/enums.py
index 58803d4..103dde3 100644
--- a/python_gpt_po/models/enums.py
+++ b/python_gpt_po/models/enums.py
@@ -10,3 +10,10 @@ class ModelProvider(Enum):
     OPENAI = "openai"
     ANTHROPIC = "anthropic"
     DEEPSEEK = "deepseek"
+
+
+ModelProviderList = [
+    ModelProvider.OPENAI.value,
+    ModelProvider.ANTHROPIC.value,
+    ModelProvider.DEEPSEEK.value
+]
diff --git a/python_gpt_po/models/provider_clients.py b/python_gpt_po/models/provider_clients.py
index 11e9cfe..f451535 100644
--- a/python_gpt_po/models/provider_clients.py
+++ b/python_gpt_po/models/provider_clients.py
@@ -7,6 +7,8 @@
 from anthropic import Anthropic
 from openai import OpenAI
 
+from .enums import ModelProvider
+
 
 class ProviderClients:
     """Class to store API clients for various providers."""
@@ -23,11 +25,11 @@ def initialize_clients(self, api_keys: Dict[str, str]):
         Args:
             api_keys (Dict[str, str]): Dictionary of provider names to API keys
         """
-        if api_keys.get("openai"):
-            self.openai_client = OpenAI(api_key=api_keys["openai"])
+        if api_keys.get(ModelProvider.OPENAI.value):
+            self.openai_client = OpenAI(api_key=api_keys[ModelProvider.OPENAI.value])
 
-        if api_keys.get("anthropic"):
-            self.anthropic_client = Anthropic(api_key=api_keys["anthropic"])
+        if api_keys.get(ModelProvider.ANTHROPIC.value):
+            self.anthropic_client = Anthropic(api_key=api_keys[ModelProvider.ANTHROPIC.value])
 
-        if api_keys.get("deepseek"):
-            self.deepseek_api_key = api_keys["deepseek"]
+        if api_keys.get(ModelProvider.DEEPSEEK.value):
+            self.deepseek_api_key = api_keys[ModelProvider.DEEPSEEK.value]
diff --git a/python_gpt_po/utils/cli.py b/python_gpt_po/utils/cli.py
index e105afd..e0da78f 100644
--- a/python_gpt_po/utils/cli.py
+++ b/python_gpt_po/utils/cli.py
@@ -9,7 +9,7 @@
 import sys
 from typing import Dict, List, Optional
 
-from ..models.enums import ModelProvider
+from ..models.enums import ModelProvider, ModelProviderList
 from .helpers import get_version
 
 
@@ -99,7 +99,7 @@ def parse_args():
     # Provider settings
     provider_group.add_argument(
         "--provider",
-        choices=["openai", "anthropic", "deepseek"],
+        choices=ModelProviderList,
         help="AI provider to use (default: first provider with available API key)"
     )
     provider_group.add_argument(
@@ -248,9 +248,9 @@ def get_api_keys_from_args(args) -> Dict[str, str]:
         Dict[str, str]: Dictionary of provider names to API keys
     """
     return {
-        "openai": args.openai_key or args.api_key or os.getenv("OPENAI_API_KEY", ""),
-        "anthropic": args.anthropic_key or os.getenv("ANTHROPIC_API_KEY", ""),
-        "deepseek": args.deepseek_key or os.getenv("DEEPSEEK_API_KEY", "")
+        ModelProvider.OPENAI.value: args.openai_key or args.api_key or os.getenv("OPENAI_API_KEY", ""),
+        ModelProvider.ANTHROPIC.value: args.anthropic_key or os.getenv("ANTHROPIC_API_KEY", ""),
+        ModelProvider.DEEPSEEK.value: args.deepseek_key or os.getenv("DEEPSEEK_API_KEY", "")
     }
 
 
@@ -264,7 +264,7 @@ def auto_select_provider(api_keys: Dict[str, str]) -> Optional[ModelProvider]:
     Returns:
         Optional[ModelProvider]: The auto-selected provider or None if no keys available
     """
-    for provider_name in ["openai", "anthropic", "deepseek"]:
+    for provider_name in ModelProviderList:
         if api_keys.get(provider_name):
             provider = ModelProvider(provider_name)
             logging.info("Auto-selected provider: %s (based on available API key)", provider_name)