2 files changed, 24 insertions, 19 deletions

diff --git a/g4f/providers/base_provider.py b/g4f/providers/base_provider.py
index ee5bcbb8..37f4af15 100644
--- a/g4f/providers/base_provider.py
+++ b/g4f/providers/base_provider.py
@@ -6,9 +6,10 @@ from asyncio import AbstractEventLoop
 from concurrent.futures import ThreadPoolExecutor
 from abc import abstractmethod
 from inspect import signature, Parameter
-from ..typing import CreateResult, AsyncResult, Messages, Union
-from .types import BaseProvider
-from ..errors import NestAsyncioError, ModelNotSupportedError
+from typing import Callable, Union
+from ..typing import CreateResult, AsyncResult, Messages
+from .types import BaseProvider, FinishReason
+from ..errors import NestAsyncioError, ModelNotSupportedError, MissingRequirementsError
 from .. import debug
 
 if sys.version_info < (3, 10):
@@ -21,17 +22,23 @@ if sys.platform == 'win32':
     if isinstance(asyncio.get_event_loop_policy(), asyncio.WindowsProactorEventLoopPolicy):
         asyncio.set_event_loop_policy(asyncio.WindowsSelectorEventLoopPolicy())
 
-def get_running_loop() -> Union[AbstractEventLoop, None]:
+def get_running_loop(check_nested: bool) -> Union[AbstractEventLoop, None]:
     try:
         loop = asyncio.get_running_loop()
-        if not hasattr(loop.__class__, "_nest_patched"):
-            raise NestAsyncioError(
-                'Use "create_async" instead of "create" function in a running event loop. Or use "nest_asyncio" package.'
-            )
+        if check_nested and not hasattr(loop.__class__, "_nest_patched"):
+            try:
+                import nest_asyncio
+                nest_asyncio.apply(loop)
+            except ImportError:
+                raise MissingRequirementsError('Install "nest_asyncio" package')
         return loop
     except RuntimeError:
         pass
 
+# Fix for RuntimeError: async generator ignored GeneratorExit
+async def await_callback(callback: Callable):
+    return await callback()
+
 class AbstractProvider(BaseProvider):
     """
     Abstract class for providing asynchronous functionality to derived classes.
@@ -132,7 +139,7 @@ class AsyncProvider(AbstractProvider):
         Returns:
             CreateResult: The result of the completion creation.
         """
-        get_running_loop()
+        get_running_loop(check_nested=True)
         yield asyncio.run(cls.create_async(model, messages, **kwargs))
 
     @staticmethod
@@ -158,7 +165,6 @@ class AsyncProvider(AbstractProvider):
         """
         raise NotImplementedError()
 
-
 class AsyncGeneratorProvider(AsyncProvider):
     """
     Provides asynchronous generator functionality for streaming results.
@@ -187,9 +193,9 @@ class AsyncGeneratorProvider(AsyncProvider):
         Returns:
             CreateResult: The result of the streaming completion creation.
         """
-        loop = get_running_loop()
+        loop = get_running_loop(check_nested=True)
         new_loop = False
-        if not loop:
+        if loop is None:
             loop = asyncio.new_event_loop()
             asyncio.set_event_loop(loop)
             new_loop = True
@@ -197,16 +203,11 @@ class AsyncGeneratorProvider(AsyncProvider):
         generator = cls.create_async_generator(model, messages, stream=stream, **kwargs)
         gen = generator.__aiter__()
 
-        # Fix for RuntimeError: async generator ignored GeneratorExit
-        async def await_callback(callback):
-            return await callback()
-
         try:
             while True:
                 yield loop.run_until_complete(await_callback(gen.__anext__))
         except StopAsyncIteration:
             ...
-        # Fix for: ResourceWarning: unclosed event loop
         finally:
             if new_loop:
                 loop.close()
@@ -233,7 +234,7 @@ class AsyncGeneratorProvider(AsyncProvider):
         """
         return "".join([
             chunk async for chunk in cls.create_async_generator(model, messages, stream=False, **kwargs) 
-            if not isinstance(chunk, Exception)
+            if not isinstance(chunk, (Exception, FinishReason))
         ])
 
     @staticmethod
diff --git a/g4f/providers/types.py b/g4f/providers/types.py
index 67340958..a3eeb99e 100644
--- a/g4f/providers/types.py
+++ b/g4f/providers/types.py
@@ -97,4 +97,8 @@ class BaseRetryProvider(BaseProvider):
     __name__: str = "RetryProvider"
     supports_stream: bool = True
 
-ProviderType = Union[Type[BaseProvider], BaseRetryProvider]
\ No newline at end of file
+ProviderType = Union[Type[BaseProvider], BaseRetryProvider]
+
+class FinishReason():
+    def __init__(self, reason: str):
+        self.reason = reason
\ No newline at end of file