langchain[patch]: allow passing client with OpenAIAssistantRunnable (#16486)

- **Description:** This addresses the issue tagged below where if you
try to pass your own client when creating an OpenAI assistant, a
pydantic error is raised:

Example code:

```python
import openai
from langchain.agents.openai_assistant import OpenAIAssistantRunnable

client = openai.OpenAI()
interpreter_assistant = OpenAIAssistantRunnable.create_assistant(
    name="langchain assistant",
    instructions="You are a personal math tutor. Write and run code to answer math questions.",
    tools=[{"type": "code_interpreter"}],
    model="gpt-4-1106-preview",
    client=client
)

```

Error:
`pydantic.v1.errors.ConfigError: field "client" not yet prepared, so the
type is still a ForwardRef. You might need to call
OpenAIAssistantRunnable.update_forward_refs()`

It additionally updates type hints and docstrings to indicate that an
AzureOpenAI client is permissible as well.

  - **Issue:** https://github.com/langchain-ai/langchain/issues/15948
  - **Dependencies:** N/A

libs/langchain/langchain/agents/openai_assistant/base.py

@@ -146,8 +146,8 @@ class OpenAIAssistantRunnable(RunnableSerializable[Dict, OutputType]):
 
     """  # noqa: E501
 
-    client: openai.OpenAI = Field(default_factory=_get_openai_client)
-    """OpenAI client."""
+    client: Any = Field(default_factory=_get_openai_client)
+    """OpenAI or AzureOpenAI client."""
     assistant_id: str
     """OpenAI assistant id."""
     check_every_ms: float = 1_000.0
@@ -163,7 +163,7 @@ class OpenAIAssistantRunnable(RunnableSerializable[Dict, OutputType]):
         tools: Sequence[Union[BaseTool, dict]],
         model: str,
         *,
-        client: Optional[openai.OpenAI] = None,
+        client: Optional[Union[openai.OpenAI, openai.AzureOpenAI]] = None,
         **kwargs: Any,
     ) -> OpenAIAssistantRunnable:
         """Create an OpenAI Assistant and instantiate the Runnable.
@@ -173,7 +173,8 @@ class OpenAIAssistantRunnable(RunnableSerializable[Dict, OutputType]):
             instructions: Assistant instructions.
             tools: Assistant tools. Can be passed in OpenAI format or as BaseTools.
             model: Assistant model to use.
-            client: OpenAI client. Will create default client if not specified.
+            client: OpenAI or AzureOpenAI client.
+                Will create default OpenAI client if not specified.
 
         Returns:
             OpenAIAssistantRunnable configured to run using the created assistant.
@@ -191,7 +192,7 @@ class OpenAIAssistantRunnable(RunnableSerializable[Dict, OutputType]):
             tools=openai_tools,
             model=model,
         )
-        return cls(assistant_id=assistant.id, **kwargs)
+        return cls(assistant_id=assistant.id, client=client, **kwargs)
 
     def invoke(
         self, input: dict, config: Optional[RunnableConfig] = None

libs/langchain/tests/unit_tests/agents/test_openai_assistant.py

@@ -0,0 +1,21 @@
+import pytest
+
+from langchain.agents.openai_assistant import OpenAIAssistantRunnable
+
+
+@pytest.mark.requires("openai")
+def test_user_supplied_client() -> None:
+    import openai
+
+    client = openai.AzureOpenAI(
+        azure_endpoint="azure_endpoint",
+        api_key="api_key",
+        api_version="api_version",
+    )
+
+    assistant = OpenAIAssistantRunnable(
+        assistant_id="assistant_id",
+        client=client,
+    )
+
+    assert assistant.client == client