feat: add OpenAI Responses API model implementation (#975)

Co-authored-by: Strands Agent <217235299+strands-agent@users.noreply.github.com>

Author: notgitika

README.md

@@ -179,6 +179,7 @@ Built-in providers:
  - [MistralAI](https://strandsagents.com/latest/user-guide/concepts/model-providers/mistral/)
  - [Ollama](https://strandsagents.com/latest/user-guide/concepts/model-providers/ollama/)
  - [OpenAI](https://strandsagents.com/latest/user-guide/concepts/model-providers/openai/)
+ - [OpenAI Responses API](https://strandsagents.com/latest/user-guide/concepts/model-providers/openai/)
  - [SageMaker](https://strandsagents.com/latest/user-guide/concepts/model-providers/sagemaker/)
  - [Writer](https://strandsagents.com/latest/user-guide/concepts/model-providers/writer/)
 

src/strands/models/__init__.py

@@ -55,6 +55,10 @@ def __getattr__(name: str) -> Any:
         from .openai import OpenAIModel
 
         return OpenAIModel
+    if name == "OpenAIResponsesModel":
+        from .openai_responses import OpenAIResponsesModel
+
+        return OpenAIResponsesModel
     if name == "SageMakerAIModel":
         from .sagemaker import SageMakerAIModel
 

src/strands/models/openai_responses.py

@@ -0,0 +1,25 @@
+"""Pytest configuration for model tests."""
+
+import sys
+import unittest.mock
+
+# Mock OpenAI version check before the openai_responses module is imported.
+# This is necessary because the version check happens at module import time.
+# We patch importlib.metadata.version directly since that's where get_package_version comes from.
+if "strands.models.openai_responses" not in sys.modules:
+    _original_version = None
+    try:
+        from importlib.metadata import version as _original_version_func
+
+        _original_version = _original_version_func
+    except ImportError:
+        pass
+
+    def _mock_version(package_name: str) -> str:
+        if package_name == "openai":
+            return "2.0.0"
+        if _original_version:
+            return _original_version(package_name)
+        raise Exception(f"Package {package_name} not found")
+
+    unittest.mock.patch("importlib.metadata.version", _mock_version).start()