feat(openai): add callable support for openai_api_key parameter (#33532)

libs/partners/openai/tests/integration_tests/chat_models/test_base.py

@@ -2,6 +2,7 @@
 
 import base64
 import json
+import os
 from collections.abc import AsyncIterator
 from pathlib import Path
 from textwrap import dedent
@@ -64,6 +65,57 @@ def test_chat_openai_model() -> None:
     assert chat.model_name == "bar"
 
 
+def test_callable_api_key(monkeypatch: pytest.MonkeyPatch) -> None:
+    original_key = os.environ["OPENAI_API_KEY"]
+
+    calls = {"sync": 0}
+
+    def get_openai_api_key() -> str:
+        calls["sync"] += 1
+        return original_key
+
+    monkeypatch.delenv("OPENAI_API_KEY")
+
+    model = ChatOpenAI(model="gpt-4.1-mini", api_key=get_openai_api_key)
+    response = model.invoke("hello")
+    assert isinstance(response, AIMessage)
+    assert calls["sync"] == 1
+
+
+async def test_callable_api_key_async(monkeypatch: pytest.MonkeyPatch) -> None:
+    original_key = os.environ["OPENAI_API_KEY"]
+
+    calls = {"sync": 0, "async": 0}
+
+    def get_openai_api_key() -> str:
+        calls["sync"] += 1
+        return original_key
+
+    async def get_openai_api_key_async() -> str:
+        calls["async"] += 1
+        return original_key
+
+    monkeypatch.delenv("OPENAI_API_KEY")
+
+    model = ChatOpenAI(model="gpt-4.1-mini", api_key=get_openai_api_key)
+    response = model.invoke("hello")
+    assert isinstance(response, AIMessage)
+    assert calls["sync"] == 1
+
+    response = await model.ainvoke("hello")
+    assert isinstance(response, AIMessage)
+    assert calls["sync"] == 2
+
+    model = ChatOpenAI(model="gpt-4.1-mini", api_key=get_openai_api_key_async)
+    async_response = await model.ainvoke("hello")
+    assert isinstance(async_response, AIMessage)
+    assert calls["async"] == 1
+
+    with pytest.raises(ValueError):
+        # We do not create a sync callable from an async one
+        _ = model.invoke("hello")
+
+
 @pytest.mark.parametrize("use_responses_api", [False, True])
 def test_chat_openai_system_message(use_responses_api: bool) -> None:
     """Test ChatOpenAI wrapper with system message."""

libs/partners/openai/tests/integration_tests/embeddings/test_base.py

@@ -1,7 +1,10 @@
 """Test OpenAI embeddings."""
 
+import os
+
 import numpy as np
 import openai
+import pytest
 
 from langchain_openai.embeddings.base import OpenAIEmbeddings
 
@@ -67,3 +70,56 @@ def test_langchain_openai_embeddings_dimensions_large_num() -> None:
     output = embedding.embed_documents(documents)
     assert len(output) == 2000
     assert len(output[0]) == 128
+
+
+def test_callable_api_key(monkeypatch: pytest.MonkeyPatch) -> None:
+    original_key = os.environ["OPENAI_API_KEY"]
+
+    calls = {"sync": 0}
+
+    def get_openai_api_key() -> str:
+        calls["sync"] += 1
+        return original_key
+
+    monkeypatch.delenv("OPENAI_API_KEY")
+
+    model = OpenAIEmbeddings(
+        model="text-embedding-3-small", dimensions=128, api_key=get_openai_api_key
+    )
+    _ = model.embed_query("hello")
+    assert calls["sync"] == 1
+
+
+async def test_callable_api_key_async(monkeypatch: pytest.MonkeyPatch) -> None:
+    original_key = os.environ["OPENAI_API_KEY"]
+
+    calls = {"sync": 0, "async": 0}
+
+    def get_openai_api_key() -> str:
+        calls["sync"] += 1
+        return original_key
+
+    async def get_openai_api_key_async() -> str:
+        calls["async"] += 1
+        return original_key
+
+    monkeypatch.delenv("OPENAI_API_KEY")
+
+    model = OpenAIEmbeddings(
+        model="text-embedding-3-small", dimensions=128, api_key=get_openai_api_key
+    )
+    _ = model.embed_query("hello")
+    assert calls["sync"] == 1
+
+    _ = await model.aembed_query("hello")
+    assert calls["sync"] == 2
+
+    model = OpenAIEmbeddings(
+        model="text-embedding-3-small", dimensions=128, api_key=get_openai_api_key_async
+    )
+    _ = await model.aembed_query("hello")
+    assert calls["async"] == 1
+
+    with pytest.raises(ValueError):
+        # We do not create a sync callable from an async one
+        _ = model.embed_query("hello")

libs/partners/openai/tests/unit_tests/test_secrets.py

@@ -187,6 +187,18 @@ def test_openai_uses_actual_secret_value_from_secretstr(model_class: type) -> No
     assert cast(SecretStr, model.openai_api_key).get_secret_value() == "secret-api-key"
 
 
+@pytest.mark.parametrize("model_class", [ChatOpenAI, OpenAI, OpenAIEmbeddings])
+def test_openai_api_key_accepts_callable(model_class: type) -> None:
+    """Test that the API key can be passed as a callable."""
+
+    def get_api_key() -> str:
+        return "secret-api-key-from-callable"
+
+    model = model_class(openai_api_key=get_api_key)
+    assert callable(model.openai_api_key)
+    assert model.openai_api_key() == "secret-api-key-from-callable"
+
+
 @pytest.mark.parametrize("model_class", [AzureChatOpenAI, AzureOpenAI])
 def test_azure_serialized_secrets(model_class: type) -> None:
     """Test that the actual secret value is correctly retrieved."""