diff --git a/README.md b/README.md
index bee1ada..07761bd 100644
--- a/README.md
+++ b/README.md
@@ -48,6 +48,7 @@ AI_API_TOKEN=<your_github_token>
 # MCP configs
 GH_TOKEN=<your_github_token>
 CODEQL_DBS_BASE_PATH="/app/my_data/codeql_databases"
+AI_API_ENDPOINT="https://models.github.ai/inference"
 ```
 
 ## Deploying from Source
diff --git a/src/seclab_taskflow_agent/agent.py b/src/seclab_taskflow_agent/agent.py
index 6c26b0b..06097c1 100644
--- a/src/seclab_taskflow_agent/agent.py
+++ b/src/seclab_taskflow_agent/agent.py
@@ -27,7 +27,10 @@
     case AI_API_ENDPOINT_ENUM.AI_API_MODELS_GITHUB:
         default_model = 'openai/gpt-4o'
     case _:
-        raise ValueError(f"Unsupported Model Endpoint: {api_endpoint}")
+        raise ValueError(
+            f"Unsupported Model Endpoint: {api_endpoint}\n"
+            f"Supported endpoints: {[e.to_url() for e in AI_API_ENDPOINT_ENUM]}"
+        )
 
 DEFAULT_MODEL = os.getenv('COPILOT_DEFAULT_MODEL', default=default_model)
 
diff --git a/src/seclab_taskflow_agent/capi.py b/src/seclab_taskflow_agent/capi.py
index 54744d4..478ea56 100644
--- a/src/seclab_taskflow_agent/capi.py
+++ b/src/seclab_taskflow_agent/capi.py
@@ -11,8 +11,20 @@
 
 # Enumeration of currently supported API endpoints.
 class AI_API_ENDPOINT_ENUM(StrEnum):
-  AI_API_MODELS_GITHUB = 'models.github.ai'
-  AI_API_GITHUBCOPILOT = 'api.githubcopilot.com'
+    AI_API_MODELS_GITHUB = 'models.github.ai'
+    AI_API_GITHUBCOPILOT = 'api.githubcopilot.com'
+
+    def to_url(self):
+        """
+        Convert the endpoint to its full URL.
+        """
+        match self:
+            case AI_API_ENDPOINT_ENUM.AI_API_GITHUBCOPILOT:
+                return f"https://{self}"
+            case AI_API_ENDPOINT_ENUM.AI_API_MODELS_GITHUB:
+                return f"https://{self}/inference"
+            case _:
+                raise ValueError(f"Unsupported endpoint: {self}")
 
 COPILOT_INTEGRATION_ID = 'vscode-chat'
 
@@ -21,7 +33,7 @@ class AI_API_ENDPOINT_ENUM(StrEnum):
 # since different APIs use their own id schema, use -l with your desired
 # endpoint to retrieve the correct id names to use for your taskflow
 def get_AI_endpoint():
-  return os.getenv('AI_API_ENDPOINT', default='https://models.github.ai/inference')
+    return os.getenv('AI_API_ENDPOINT', default='https://models.github.ai/inference')
 
 def get_AI_token():
     """
@@ -50,7 +62,8 @@ def list_capi_models(token: str) -> dict[str, dict]:
             case AI_API_ENDPOINT_ENUM.AI_API_MODELS_GITHUB:
                 models_catalog = 'catalog/models'
             case _:
-                raise ValueError(f"Unsupported Model Endpoint: {api_endpoint}")
+                raise ValueError(f"Unsupported Model Endpoint: {api_endpoint}\n"
+                                 f"Supported endpoints: {[e.to_url() for e in AI_API_ENDPOINT_ENUM]}")
         r = httpx.get(httpx.URL(api_endpoint).join(models_catalog),
                       headers={
                           'Accept': 'application/json',
@@ -64,8 +77,6 @@ def list_capi_models(token: str) -> dict[str, dict]:
                 models_list = r.json().get('data', [])
             case AI_API_ENDPOINT_ENUM.AI_API_MODELS_GITHUB:
                 models_list = r.json()
-            case _:
-                raise ValueError(f"Unsupported Model Endpoint: {api_endpoint}")
         for model in models_list:
             models[model.get('id')] = dict(model)
     except httpx.RequestError as e:
@@ -88,7 +99,10 @@ def supports_tool_calls(model: str, models: dict) -> bool:
             return 'tool-calling' in models.get(model, {}).\
                 get('capabilities', [])
         case _:
-            raise ValueError(f"Unsupported Model Endpoint: {api_endpoint}")
+            raise ValueError(
+                f"Unsupported Model Endpoint: {api_endpoint}\n"
+                f"Supported endpoints: {[e.to_url() for e in AI_API_ENDPOINT_ENUM]}"
+            )
 
 def list_tool_call_models(token: str) -> dict[str, dict]:
     models = list_capi_models(token)
diff --git a/tests/test_api_endpoint_config.py b/tests/test_api_endpoint_config.py
index 654b44e..96e0216 100644
--- a/tests/test_api_endpoint_config.py
+++ b/tests/test_api_endpoint_config.py
@@ -8,7 +8,7 @@
 import pytest
 import os
 from urllib.parse import urlparse
-from seclab_taskflow_agent.capi import get_AI_endpoint, AI_API_ENDPOINT_ENUM
+from seclab_taskflow_agent.capi import get_AI_endpoint, AI_API_ENDPOINT_ENUM, list_capi_models
 
 class TestAPIEndpoint:
     """Test API endpoint configuration."""
@@ -43,5 +43,26 @@ def test_api_endpoint_env_override(self):
             if original_env:
                 os.environ['AI_API_ENDPOINT'] = original_env
 
+    def test_to_url_models_github(self):
+        """Test to_url method for models.github.ai endpoint."""
+        endpoint = AI_API_ENDPOINT_ENUM.AI_API_MODELS_GITHUB
+        assert endpoint.to_url() == 'https://models.github.ai/inference'
+
+    def test_to_url_githubcopilot(self):
+        """Test to_url method for GitHub Copilot endpoint."""
+        endpoint = AI_API_ENDPOINT_ENUM.AI_API_GITHUBCOPILOT
+        assert endpoint.to_url() == 'https://api.githubcopilot.com'
+
+    def test_unsupported_endpoint(self, monkeypatch):
+        """Test that unsupported API endpoint raises ValueError."""
+        api_endpoint = 'https://unsupported.example.com'
+        monkeypatch.setenv('AI_API_ENDPOINT', api_endpoint)
+        with pytest.raises(ValueError) as excinfo:
+            list_capi_models("abc")
+        msg = str(excinfo.value)
+        assert 'Unsupported Model Endpoint' in msg
+        assert 'https://models.github.ai/inference' in msg
+        assert 'https://api.githubcopilot.com' in msg
+
 if __name__ == '__main__':
     pytest.main([__file__, '-v'])