feat: add support for copilot provider (#8577)

* feat: add support for copilot provider

* test: add tests for github copilot

* chore: clean up github copilot authenticator

* test: add test for github copilot authenticator

* test: add test for github copilot for sonnet 3.7 thought model

---------

Co-authored-by: Krish Dholakia <krrishdholakia@gmail.com>

.gitignore

@@ -77,5 +77,3 @@ litellm/proxy/_experimental/out/404.html
 litellm/proxy/_experimental/out/model_hub.html
 .mypy_cache/*
 litellm/proxy/application.log
-tests/llm_translation/vertex_test_account.json
-tests/llm_translation/test_vertex_key.json

litellm/__init__.py

@@ -980,6 +980,7 @@ from .llms.azure.chat.o_series_transformation import AzureOpenAIO1Config
 from .llms.watsonx.completion.transformation import IBMWatsonXAIConfig
 from .llms.watsonx.chat.transformation import IBMWatsonXChatConfig
 from .llms.watsonx.embed.transformation import IBMWatsonXEmbeddingConfig
+from .llms.github_copilot.chat.transformation import GithubCopilotConfig
 from .main import *  # type: ignore
 from .integrations import *
 from .exceptions import (

litellm/constants.py

@@ -79,6 +79,7 @@ LITELLM_CHAT_PROVIDERS = [
     "hosted_vllm",
     "lm_studio",
     "galadriel",
+    "github_copilot",  # GitHub Copilot Chat API
 ]
 
 
@@ -138,7 +139,7 @@ openai_compatible_endpoints: List = [
     "https://api.friendli.ai/serverless/v1",
     "api.sambanova.ai/v1",
     "api.x.ai/v1",
-    "api.galadriel.ai/v1",
+    "api.galadriel.ai/v1"
 ]
 
 
@@ -168,6 +169,7 @@ openai_compatible_providers: List = [
     "hosted_vllm",
     "lm_studio",
     "galadriel",
+    "github_copilot",  # GitHub Copilot Chat API
 ]
 openai_text_completion_compatible_providers: List = (
     [  # providers that support `/v1/completions`

litellm/litellm_core_utils/get_llm_provider_logic.py

@@ -571,6 +571,14 @@ def _get_openai_compatible_provider_info(  # noqa: PLR0915
             or "https://api.galadriel.com/v1"
         )  # type: ignore
         dynamic_api_key = api_key or get_secret_str("GALADRIEL_API_KEY")
+    elif custom_llm_provider == "github_copilot":
+        (
+            api_base,
+            dynamic_api_key,
+            custom_llm_provider,
+        ) = litellm.GithubCopilotConfig()._get_openai_compatible_provider_info(
+            model, api_base, api_key, custom_llm_provider
+        )
     if api_base is not None and not isinstance(api_base, str):
         raise Exception("api base needs to be a string. api_base={}".format(api_base))
     if dynamic_api_key is not None and not isinstance(dynamic_api_key, str):

litellm/llms/github_copilot/__init__.py

@@ -0,0 +1,17 @@
+from .constants import (
+    GITHUB_COPILOT_API_BASE,
+    CHAT_COMPLETION_ENDPOINT,
+    GITHUB_COPILOT_MODEL,
+    GetAccessTokenError,
+    GetAPIKeyError,
+    RefreshAPIKeyError,
+)
+
+__all__ = [
+    "GITHUB_COPILOT_API_BASE",
+    "CHAT_COMPLETION_ENDPOINT",
+    "GITHUB_COPILOT_MODEL",
+    "GetAccessTokenError",
+    "GetAPIKeyError",
+    "RefreshAPIKeyError",
+]

litellm/llms/github_copilot/authenticator.py

@@ -0,0 +1,292 @@
+import os
+import httpx
+import json
+import time
+from datetime import datetime
+from typing import Optional, Dict, Any
+
+from litellm._logging import verbose_logger
+from litellm.caching import InMemoryCache
+from litellm.llms.custom_httpx.http_handler import (
+    _get_httpx_client,
+    get_async_httpx_client,
+    httpxSpecialProvider,
+)
+
+from .constants import (
+    GetAccessTokenError,
+    GetDeviceCodeError,
+    RefreshAPIKeyError,
+    GetAPIKeyError,
+    APIKeyExpiredError,
+)
+
+# Constants
+GITHUB_CLIENT_ID = "Iv1.b507a08c87ecfe98"
+GITHUB_DEVICE_CODE_URL = "https://github.com/login/device/code"
+GITHUB_ACCESS_TOKEN_URL = "https://github.com/login/oauth/access_token"
+GITHUB_API_KEY_URL = "https://api.github.com/copilot_internal/v2/token"
+
+
+class Authenticator:
+    def __init__(self) -> None:
+        """Initialize the GitHub Copilot authenticator with configurable token paths."""
+        # Token storage paths
+        self.token_dir = os.getenv(
+            "GITHUB_COPILOT_TOKEN_DIR",
+            os.path.expanduser("~/.config/litellm/github_copilot"),
+        )
+        self.access_token_file = os.path.join(
+            self.token_dir,
+            os.getenv("GITHUB_COPILOT_ACCESS_TOKEN_FILE", "access-token"),
+        )
+        self.api_key_file = os.path.join(
+            self.token_dir, os.getenv("GITHUB_COPILOT_API_KEY_FILE", "api-key.json")
+        )
+        self._ensure_token_dir()
+
+    def get_access_token(self) -> str:
+        """
+        Login to Copilot with retry 3 times.
+
+        Returns:
+            str: The GitHub access token.
+
+        Raises:
+            GetAccessTokenError: If unable to obtain an access token after retries.
+        """
+        try:
+            with open(self.access_token_file, "r") as f:
+                access_token = f.read().strip()
+                if access_token:
+                    return access_token
+        except IOError:
+            verbose_logger.warning("No existing access token found or error reading file")
+
+        for attempt in range(3):
+            verbose_logger.debug(f"Access token acquisition attempt {attempt + 1}/3")
+            try:
+                access_token = self._login()
+                try:
+                    with open(self.access_token_file, "w") as f:
+                        f.write(access_token)
+                except IOError:
+                    verbose_logger.error("Error saving access token to file")
+                return access_token
+            except (GetDeviceCodeError, GetAccessTokenError, RefreshAPIKeyError) as e:
+                verbose_logger.warning(f"Failed attempt {attempt + 1}: {str(e)}")
+                continue
+
+        raise GetAccessTokenError("Failed to get access token after 3 attempts")
+
+    def get_api_key(self) -> str:
+        """
+        Get the API key, refreshing if necessary.
+
+        Returns:
+            str: The GitHub Copilot API key.
+
+        Raises:
+            GetAPIKeyError: If unable to obtain an API key.
+        """
+        try:
+            with open(self.api_key_file, "r") as f:
+                api_key_info = json.load(f)
+                if api_key_info.get("expires_at", 0) > datetime.now().timestamp():
+                    return api_key_info.get("token")
+                else:
+                    verbose_logger.warning("API key expired, refreshing")
+                    raise APIKeyExpiredError("API key expired")
+        except IOError:
+            verbose_logger.warning("No API key file found or error opening file")
+        except (json.JSONDecodeError, KeyError) as e:
+            verbose_logger.warning(f"Error reading API key from file: {str(e)}")
+        except APIKeyExpiredError:
+            pass  # Already logged in the try block
+
+        try:
+            api_key_info = self._refresh_api_key()
+            with open(self.api_key_file, "w") as f:
+                json.dump(api_key_info, f)
+            return api_key_info.get("token")
+        except IOError as e:
+            verbose_logger.error(f"Error saving API key to file: {str(e)}")
+            raise GetAPIKeyError(f"Failed to save API key: {str(e)}")
+        except RefreshAPIKeyError as e:
+            raise GetAPIKeyError(f"Failed to refresh API key: {str(e)}")
+
+    def _refresh_api_key(self) -> Dict[str, Any]:
+        """
+        Refresh the API key using the access token.
+
+        Returns:
+            Dict[str, Any]: The API key information including token and expiration.
+
+        Raises:
+            RefreshAPIKeyError: If unable to refresh the API key.
+        """
+        access_token = self.get_access_token()
+        headers = self._get_github_headers(access_token)
+
+        max_retries = 3
+        for attempt in range(max_retries):
+            try:
+                sync_client = _get_httpx_client()
+                response = sync_client.get(
+                    GITHUB_API_KEY_URL, headers=headers
+                )
+                response.raise_for_status()
+
+                response_json = response.json()
+
+                if "token" in response_json:
+                    return response_json
+                else:
+                    verbose_logger.warning(f"API key response missing token: {response_json}")
+            except httpx.HTTPStatusError as e:
+                verbose_logger.error(f"HTTP error refreshing API key (attempt {attempt+1}/{max_retries}): {str(e)}")
+            except Exception as e:
+                verbose_logger.error(f"Unexpected error refreshing API key: {str(e)}")
+
+        raise RefreshAPIKeyError("Failed to refresh API key after maximum retries")
+
+    def _ensure_token_dir(self) -> None:
+        """Ensure the token directory exists."""
+        if not os.path.exists(self.token_dir):
+            os.makedirs(self.token_dir, exist_ok=True)
+
+    def _get_github_headers(self, access_token: Optional[str] = None) -> Dict[str, str]:
+        """
+        Generate standard GitHub headers for API requests.
+        
+        Args:
+            access_token: Optional access token to include in the headers.
+            
+        Returns:
+            Dict[str, str]: Headers for GitHub API requests.
+        """
+        headers = {
+            "accept": "application/json",
+            "editor-version": "vscode/1.85.1",
+            "editor-plugin-version": "copilot/1.155.0", 
+            "user-agent": "GithubCopilot/1.155.0",
+            "accept-encoding": "gzip,deflate,br",
+        }
+        
+        if access_token:
+            headers["authorization"] = f"token {access_token}"
+            
+        if "content-type" not in headers:
+            headers["content-type"] = "application/json"
+            
+        return headers
+
+    def _get_device_code(self) -> Dict[str, str]:
+        """
+        Get a device code for GitHub authentication.
+        
+        Returns:
+            Dict[str, str]: Device code information.
+            
+        Raises:
+            GetDeviceCodeError: If unable to get a device code.
+        """
+        try:
+            sync_client = _get_httpx_client()
+            resp = sync_client.post(
+                GITHUB_DEVICE_CODE_URL,
+                headers=self._get_github_headers(),
+                json={"client_id": GITHUB_CLIENT_ID, "scope": "read:user"},
+            )
+            resp.raise_for_status()
+            resp_json = resp.json()
+
+            required_fields = ["device_code", "user_code", "verification_uri"]
+            if not all(field in resp_json for field in required_fields):
+                verbose_logger.error(f"Response missing required fields: {resp_json}")
+                raise GetDeviceCodeError("Response missing required fields")
+                
+            return resp_json
+        except httpx.HttpError as e:
+            verbose_logger.error(f"HTTP error getting device code: {str(e)}")
+            raise GetDeviceCodeError(f"Failed to get device code: {str(e)}")
+        except json.JSONDecodeError as e:
+            verbose_logger.error(f"Error decoding JSON response: {str(e)}")
+            raise GetDeviceCodeError(f"Failed to decode device code response: {str(e)}")
+        except Exception as e:
+            verbose_logger.error(f"Unexpected error getting device code: {str(e)}")
+            raise GetDeviceCodeError(f"Failed to get device code: {str(e)}")
+
+    def _poll_for_access_token(self, device_code: str) -> str:
+        """
+        Poll for an access token after user authentication.
+        
+        Args:
+            device_code: The device code to use for polling.
+            
+        Returns:
+            str: The access token.
+            
+        Raises:
+            GetAccessTokenError: If unable to get an access token.
+        """
+        sync_client = _get_httpx_client()
+        max_attempts = 12  # 1 minute (12 * 5 seconds)
+        
+        for attempt in range(max_attempts):
+            try:
+                resp = sync_client.post(
+                    GITHUB_ACCESS_TOKEN_URL,
+                    headers=self._get_github_headers(),
+                    json={
+                        "client_id": GITHUB_CLIENT_ID,
+                        "device_code": device_code,
+                        "grant_type": "urn:ietf:params:oauth:grant-type:device_code",
+                    },
+                )
+                resp.raise_for_status()
+                resp_json = resp.json()
+
+                if "access_token" in resp_json:
+                    verbose_logger.info("Authentication successful!")
+                    return resp_json["access_token"]
+                elif "error" in resp_json and resp_json.get("error") == "authorization_pending":
+                    verbose_logger.debug(f"Authorization pending (attempt {attempt+1}/{max_attempts})")
+                else:
+                    verbose_logger.warning(f"Unexpected response: {resp_json}")
+            except httpx.HTTPStatusError as e:
+                verbose_logger.error(f"HTTP error polling for access token: {str(e)}")
+                raise GetAccessTokenError(f"Failed to get access token: {str(e)}")
+            except json.JSONDecodeError as e:
+                verbose_logger.error(f"Error decoding JSON response: {str(e)}")
+                raise GetAccessTokenError(f"Failed to decode access token response: {str(e)}")
+            except Exception as e:
+                verbose_logger.error(f"Unexpected error polling for access token: {str(e)}")
+                raise GetAccessTokenError(f"Failed to get access token: {str(e)}")
+                
+            time.sleep(5)
+            
+        raise GetAccessTokenError("Timed out waiting for user to authorize the device")
+
+    def _login(self) -> str:
+        """
+        Login to GitHub Copilot using device code flow.
+
+        Returns:
+            str: The GitHub access token.
+            
+        Raises:
+            GetDeviceCodeError: If unable to get a device code.
+            GetAccessTokenError: If unable to get an access token.
+        """
+        device_code_info = self._get_device_code()
+        
+        device_code = device_code_info["device_code"]
+        user_code = device_code_info["user_code"]
+        verification_uri = device_code_info["verification_uri"]
+
+        print(
+            f"Please visit {verification_uri} and enter code {user_code} to authenticate."
+        )
+        
+        return self._poll_for_access_token(device_code)

litellm/llms/github_copilot/chat/transformation.py

@@ -0,0 +1,37 @@
+from typing import Optional, Tuple
+
+
+from litellm.llms.openai.openai import OpenAIConfig
+
+from ..authenticator import Authenticator
+from ..constants import GetAPIKeyError
+from litellm.exceptions import AuthenticationError
+
+
+class GithubCopilotConfig(OpenAIConfig):
+    def __init__(
+        self,
+        api_key: Optional[str] = None,
+        api_base: Optional[str] = None,
+        custom_llm_provider: str = "openai",
+    ) -> None:
+        super().__init__()
+        self.authenticator = Authenticator()
+
+    def _get_openai_compatible_provider_info(
+        self,
+        model: str,
+        api_base: Optional[str],
+        api_key: Optional[str],
+        custom_llm_provider: str,
+    ) -> Tuple[Optional[str], Optional[str], str]:
+        api_base = "https://api.githubcopilot.com"
+        try:
+            dynamic_api_key = self.authenticator.get_api_key()
+        except GetAPIKeyError as e:
+            raise AuthenticationError(
+                model=model,
+                llm_provider=custom_llm_provider,
+                message=str(e),
+            )
+        return api_base, dynamic_api_key, custom_llm_provider

litellm/llms/github_copilot/constants.py

@@ -0,0 +1,38 @@
+"""
+Constants for Copilot integration
+"""
+import os
+
+# Copilot API endpoints
+GITHUB_COPILOT_API_BASE = "https://api.github.com/copilot/v1"
+CHAT_COMPLETION_ENDPOINT = "/chat/completions"
+
+# Model names
+GITHUB_COPILOT_MODEL = "gpt-4o"  # The model identifier for Copilot
+
+# Request headers
+DEFAULT_HEADERS = {
+    "Content-Type": "application/json",
+    "Accept": "application/json",
+    "User-Agent": "litellm",
+}
+
+
+class GetDeviceCodeError(Exception):
+    pass
+
+
+class GetAccessTokenError(Exception):
+    pass
+
+
+class APIKeyExpiredError(Exception):
+    pass
+
+
+class RefreshAPIKeyError(Exception):
+    pass
+
+
+class GetAPIKeyError(Exception):
+    pass

litellm/types/utils.py

@@ -1914,6 +1914,7 @@ class LlmProviders(str, Enum):
     HUMANLOOP = "humanloop"
     TOPAZ = "topaz"
     ASSEMBLYAI = "assemblyai"
+    GITHUB_COPILOT = "github_copilot"
 
 
 # Create a set of all provider values for quick lookup

tests/llm_translation/test_github_copilot.py

@@ -0,0 +1,224 @@
+import pytest
+import os
+import sys
+import json
+import asyncio
+from datetime import datetime, timedelta
+from typing import AsyncGenerator
+from unittest.mock import AsyncMock, patch, mock_open, MagicMock
+
+sys.path.insert(0, os.path.abspath("../.."))
+
+import httpx
+import pytest
+from respx import MockRouter
+
+import litellm
+from litellm import Choices, Message, ModelResponse, ModelResponse, Usage
+from litellm import completion, acompletion
+from litellm.llms.github_copilot.chat.transformation import GithubCopilotConfig
+from litellm.llms.github_copilot.authenticator import Authenticator
+from litellm.llms.github_copilot.constants import (
+    GetAccessTokenError,
+    GetDeviceCodeError,
+    RefreshAPIKeyError,
+    GetAPIKeyError,
+    APIKeyExpiredError,
+)
+from litellm.exceptions import AuthenticationError
+
+# Import at the top to make the patch work correctly
+import litellm.llms.github_copilot.chat.transformation
+
+
+def test_github_copilot_config_get_openai_compatible_provider_info():
+    """Test the GitHub Copilot configuration provider info retrieval."""
+
+    config = GithubCopilotConfig()
+
+    # Mock the authenticator to avoid actual API calls
+    mock_api_key = "gh.test-key-123456789"
+    config.authenticator = MagicMock()
+    config.authenticator.get_api_key.return_value = mock_api_key
+
+    # Test with default values
+    model = "github_copilot/gpt-4"
+    (
+        api_base,
+        dynamic_api_key,
+        custom_llm_provider,
+    ) = config._get_openai_compatible_provider_info(
+        model=model,
+        api_base=None,
+        api_key=None,
+        custom_llm_provider="github_copilot",
+    )
+
+    assert api_base == "https://api.githubcopilot.com"
+    assert dynamic_api_key == mock_api_key
+    assert custom_llm_provider == "github_copilot"
+
+    # Test with authentication failure
+    config.authenticator.get_api_key.side_effect = GetAPIKeyError(
+        "Failed to get API key"
+    )
+
+    with pytest.raises(AuthenticationError) as excinfo:
+        config._get_openai_compatible_provider_info(
+            model=model,
+            api_base=None,
+            api_key=None,
+            custom_llm_provider="github_copilot",
+        )
+
+    assert "Failed to get API key" in str(excinfo.value)
+
+
+@patch("litellm.litellm_core_utils.get_llm_provider_logic.get_llm_provider")
+@patch("litellm.llms.openai.openai.OpenAIChatCompletion.completion")
+def test_completion_github_copilot_mock_response(mock_completion, mock_get_provider):
+    """Test the completion function with GitHub Copilot provider."""
+
+    # Mock completion response
+    mock_response = MagicMock()
+    mock_response.choices = [MagicMock()]
+    mock_response.choices[0].message.content = "Hello, I'm GitHub Copilot!"
+    mock_completion.return_value = mock_response
+
+    # Test non-streaming completion
+    messages = [
+        {"role": "system", "content": "You're GitHub Copilot, an AI assistant."},
+        {"role": "user", "content": "Hello, who are you?"},
+    ]
+
+    # Create a properly formatted headers dictionary
+    headers = {
+        "editor-version": "Neovim/0.9.0",
+        "Copilot-Integration-Id": "vscode-chat",
+    }
+
+    # Patch the get_llm_provider function instead of the config method
+    # Make it return the expected tuple directly
+    mock_get_provider.return_value = (
+        "gpt-4",
+        "github_copilot",
+        "gh.test-key-123456789",
+        "https://api.githubcopilot.com",
+    )
+
+    response = completion(
+        model="github_copilot/gpt-4",
+        messages=messages,
+        extra_headers=headers,
+    )
+
+    assert response is not None
+
+    # Verify the completion call was made with the expected params
+    mock_completion.assert_called_once()
+    args, kwargs = mock_completion.call_args
+
+    # Check that the proper authorization header is set
+    assert "headers" in kwargs
+    # Check that the model name is correctly formatted
+    assert (
+        kwargs.get("model") == "gpt-4"
+    )  # Model name should be without provider prefix
+    assert kwargs.get("messages") == messages
+
+
+@patch("litellm.llms.github_copilot.authenticator.Authenticator.get_api_key")
+def test_authenticator_get_api_key(mock_get_api_key):
+    """Test the Authenticator's get_api_key method."""
+    from litellm.llms.github_copilot.authenticator import Authenticator
+
+    # Test successful API key retrieval
+    mock_get_api_key.return_value = "gh.test-key-123456789"
+    authenticator = Authenticator()
+    api_key = authenticator.get_api_key()
+
+    assert api_key == "gh.test-key-123456789"
+    mock_get_api_key.assert_called_once()
+
+    # Test API key retrieval failure
+    mock_get_api_key.reset_mock()
+    mock_get_api_key.side_effect = GetAPIKeyError("Failed to get API key")
+    authenticator = Authenticator()
+
+    with pytest.raises(GetAPIKeyError) as excinfo:
+        authenticator.get_api_key()
+
+    assert "Failed to get API key" in str(excinfo.value)
+
+
+def test_completion_github_copilot(stream=False):
+    try:
+        litellm.set_verbose = True
+        messages = [
+            {"role": "system", "content": "You are an AI programming assistant."},
+            {
+                "role": "user",
+                "content": "Write a Python function to calculate fibonacci numbers",
+            },
+        ]
+        extra_headers = {
+            "editor-version": "Neovim/0.9.0",
+            "Copilot-Integration-Id": "vscode-chat",
+        }
+        response = completion(
+            model="github_copilot/gpt-4",
+            messages=messages,
+            stream=stream,
+            extra_headers=extra_headers,
+        )
+        print(response)
+
+        if stream is True:
+            for chunk in response:
+                print(chunk)
+                assert chunk is not None
+                assert isinstance(chunk, litellm.ModelResponseStream)
+                assert isinstance(chunk.choices[0], litellm.utils.StreamingChoices)
+
+        else:
+            assert response is not None
+            assert isinstance(response, litellm.ModelResponse)
+            assert response.choices[0].message.content is not None
+    except Exception as e:
+        pytest.fail(f"Error occurred: {e}")
+
+def test_completion_github_copilot_sonnet_3_7_thought(stream=False):
+    try:
+        litellm.set_verbose = True
+        messages = [
+            {"role": "system", "content": "You are an AI programming assistant."},
+            {
+                "role": "user",
+                "content": "Write a Python function to calculate fibonacci numbers",
+            },
+        ]
+        extra_headers = {
+            "editor-version": "Neovim/0.9.0",
+            "Copilot-Integration-Id": "vscode-chat",
+        }
+        response = completion(
+            model="github_copilot/claude-3.7-sonnet-thought",
+            messages=messages,
+            stream=stream,
+            extra_headers=extra_headers,
+        )
+        print(response)
+
+        if stream is True:
+            for chunk in response:
+                print(chunk)
+                assert chunk is not None
+                assert isinstance(chunk, litellm.ModelResponseStream)
+                assert isinstance(chunk.choices[0], litellm.utils.StreamingChoices)
+
+        else:
+            assert response is not None
+            assert isinstance(response, litellm.ModelResponse)
+            assert response.choices[0].message.content is not None
+    except Exception as e:
+        pytest.fail(f"Error occurred: {e}")

tests/llm_translation/test_github_copilot_authenticator.py

@@ -0,0 +1,179 @@
+import os
+import json
+import time
+from datetime import datetime, timedelta
+import pytest
+from unittest.mock import patch, mock_open, MagicMock
+
+from litellm.llms.github_copilot.authenticator import Authenticator
+from litellm.llms.github_copilot.constants import (
+    GetAccessTokenError,
+    GetDeviceCodeError,
+    RefreshAPIKeyError,
+    GetAPIKeyError,
+    APIKeyExpiredError,
+)
+
+
+class TestGitHubCopilotAuthenticator:
+    @pytest.fixture
+    def authenticator(self):
+        with patch("os.path.exists", return_value=False), patch("os.makedirs") as mock_makedirs:
+            auth = Authenticator()
+            mock_makedirs.assert_called_once()
+            return auth
+
+    @pytest.fixture
+    def mock_http_client(self):
+        mock_client = MagicMock()
+        mock_response = MagicMock()
+        mock_client.get.return_value = mock_response
+        mock_client.post.return_value = mock_response
+        mock_response.raise_for_status.return_value = None
+        return mock_client, mock_response
+
+    def test_init(self):
+        """Test the initialization of the authenticator."""
+        with patch("os.path.exists", return_value=False), patch("os.makedirs") as mock_makedirs:
+            auth = Authenticator()
+            assert auth.token_dir.endswith("/github_copilot")
+            assert auth.access_token_file.endswith("/access-token")
+            assert auth.api_key_file.endswith("/api-key.json")
+            mock_makedirs.assert_called_once()
+
+    def test_ensure_token_dir(self):
+        """Test that the token directory is created if it doesn't exist."""
+        with patch("os.path.exists", return_value=False), patch("os.makedirs") as mock_makedirs:
+            auth = Authenticator()
+            mock_makedirs.assert_called_once_with(auth.token_dir, exist_ok=True)
+
+    def test_get_github_headers(self, authenticator):
+        """Test that GitHub headers are correctly generated."""
+        headers = authenticator._get_github_headers()
+        assert "accept" in headers
+        assert "editor-version" in headers
+        assert "user-agent" in headers
+        assert "content-type" in headers
+        
+        headers_with_token = authenticator._get_github_headers("test-token")
+        assert headers_with_token["authorization"] == "token test-token"
+
+    def test_get_access_token_from_file(self, authenticator):
+        """Test retrieving an access token from a file."""
+        mock_token = "mock-access-token"
+        
+        with patch("builtins.open", mock_open(read_data=mock_token)):
+            token = authenticator.get_access_token()
+            assert token == mock_token
+
+    def test_get_access_token_login(self, authenticator):
+        """Test logging in to get an access token."""
+        mock_token = "mock-access-token"
+        
+        with patch.object(authenticator, "_login", return_value=mock_token), \
+             patch("builtins.open", mock_open()), \
+             patch("builtins.open", side_effect=IOError) as mock_read:
+            token = authenticator.get_access_token()
+            assert token == mock_token
+            authenticator._login.assert_called_once()
+
+    def test_get_access_token_failure(self, authenticator):
+        """Test that an exception is raised after multiple login failures."""
+        with patch.object(authenticator, "_login", side_effect=GetDeviceCodeError("Test error")), \
+             patch("builtins.open", side_effect=IOError):
+            with pytest.raises(GetAccessTokenError):
+                authenticator.get_access_token()
+            assert authenticator._login.call_count == 3
+
+    def test_get_api_key_from_file(self, authenticator):
+        """Test retrieving an API key from a file."""
+        future_time = (datetime.now() + timedelta(hours=1)).timestamp()
+        mock_api_key_data = json.dumps({"token": "mock-api-key", "expires_at": future_time})
+        
+        with patch("builtins.open", mock_open(read_data=mock_api_key_data)):
+            api_key = authenticator.get_api_key()
+            assert api_key == "mock-api-key"
+
+    def test_get_api_key_expired(self, authenticator):
+        """Test refreshing an expired API key."""
+        past_time = (datetime.now() - timedelta(hours=1)).timestamp()
+        mock_expired_data = json.dumps({"token": "expired-api-key", "expires_at": past_time})
+        mock_new_data = {"token": "new-api-key", "expires_at": (datetime.now() + timedelta(hours=1)).timestamp()}
+        
+        with patch("builtins.open", mock_open(read_data=mock_expired_data)), \
+             patch.object(authenticator, "_refresh_api_key", return_value=mock_new_data), \
+             patch("json.dump") as mock_json_dump:
+            api_key = authenticator.get_api_key()
+            assert api_key == "new-api-key"
+            authenticator._refresh_api_key.assert_called_once()
+
+    def test_refresh_api_key(self, authenticator, mock_http_client):
+        """Test refreshing an API key."""
+        mock_client, mock_response = mock_http_client
+        mock_token = "mock-access-token"
+        mock_api_key_data = {"token": "new-api-key", "expires_at": 12345}
+        
+        with patch.object(authenticator, "get_access_token", return_value=mock_token), \
+             patch("litellm.llms.github_copilot.authenticator._get_httpx_client", return_value=mock_client), \
+             patch.object(mock_response, "json", return_value=mock_api_key_data):
+            result = authenticator._refresh_api_key()
+            assert result == mock_api_key_data
+            mock_client.get.assert_called_once()
+            authenticator.get_access_token.assert_called_once()
+
+    def test_refresh_api_key_failure(self, authenticator, mock_http_client):
+        """Test failure to refresh an API key."""
+        mock_client, mock_response = mock_http_client
+        mock_token = "mock-access-token"
+        
+        with patch.object(authenticator, "get_access_token", return_value=mock_token), \
+             patch("litellm.llms.github_copilot.authenticator._get_httpx_client", return_value=mock_client), \
+             patch.object(mock_response, "json", return_value={}):
+            with pytest.raises(RefreshAPIKeyError):
+                authenticator._refresh_api_key()
+            assert mock_client.get.call_count == 3
+
+    def test_get_device_code(self, authenticator, mock_http_client):
+        """Test getting a device code."""
+        mock_client, mock_response = mock_http_client
+        mock_device_code_data = {
+            "device_code": "mock-device-code",
+            "user_code": "ABCD-EFGH",
+            "verification_uri": "https://github.com/login/device"
+        }
+        
+        with patch("litellm.llms.github_copilot.authenticator._get_httpx_client", return_value=mock_client), \
+             patch.object(mock_response, "json", return_value=mock_device_code_data):
+            result = authenticator._get_device_code()
+            assert result == mock_device_code_data
+            mock_client.post.assert_called_once()
+
+    def test_poll_for_access_token(self, authenticator, mock_http_client):
+        """Test polling for an access token."""
+        mock_client, mock_response = mock_http_client
+        mock_token_data = {"access_token": "mock-access-token"}
+        
+        with patch("litellm.llms.github_copilot.authenticator._get_httpx_client", return_value=mock_client), \
+             patch.object(mock_response, "json", return_value=mock_token_data), \
+             patch("time.sleep"):
+            result = authenticator._poll_for_access_token("mock-device-code")
+            assert result == "mock-access-token"
+            mock_client.post.assert_called_once()
+
+    def test_login(self, authenticator):
+        """Test the login process."""
+        mock_device_code_data = {
+            "device_code": "mock-device-code",
+            "user_code": "ABCD-EFGH",
+            "verification_uri": "https://github.com/login/device"
+        }
+        mock_token = "mock-access-token"
+        
+        with patch.object(authenticator, "_get_device_code", return_value=mock_device_code_data), \
+             patch.object(authenticator, "_poll_for_access_token", return_value=mock_token), \
+             patch("builtins.print") as mock_print:
+            result = authenticator._login()
+            assert result == mock_token
+            authenticator._get_device_code.assert_called_once()
+            authenticator._poll_for_access_token.assert_called_once_with("mock-device-code")
+            mock_print.assert_called_once()