feat: Add executionModel serialization to api client

Author: stainless-app[bot]

README.md

@@ -28,7 +28,7 @@
   </a>
 </p>
 <!-- prettier-ignore -->
-[![PyPI version](https://img.shields.io/pypi/v/stagehand-alpha.svg?label=pypi%20(stable))](https://pypi.org/project/stagehand-alpha/)
+[![PyPI version](https://img.shields.io/pypi/v/stagehand.svg?label=pypi%20(stable))](https://pypi.org/project/stagehand/)
 
 <p align="center">
 	<a href="https://trendshift.io/repositories/12122" target="_blank"><img src="https://trendshift.io/api/badge/repositories/12122" alt="browserbase%2Fstagehand | Trendshift" style="width: 250px; height: 55px;" width="250" height="55"/></a>

src/stagehand/types/session_execute_params.py

@@ -3,14 +3,16 @@
 from __future__ import annotations
 
 from typing import Union, Optional
-from typing_extensions import Literal, Required, Annotated, TypedDict
+from typing_extensions import Literal, Required, Annotated, TypeAlias, TypedDict
 
 from .._utils import PropertyInfo
 from .model_config_param import ModelConfigParam
 
 __all__ = [
     "SessionExecuteParamsBase",
     "AgentConfig",
+    "AgentConfigExecutionModel",
+    "AgentConfigModel",
     "ExecuteOptions",
     "SessionExecuteParamsNonStreaming",
     "SessionExecuteParamsStreaming",
@@ -32,13 +34,25 @@ class SessionExecuteParamsBase(TypedDict, total=False):
     """Whether to stream the response via SSE"""
 
 
+AgentConfigExecutionModel: TypeAlias = Union[ModelConfigParam, str]
+
+AgentConfigModel: TypeAlias = Union[ModelConfigParam, str]
+
+
 class AgentConfig(TypedDict, total=False):
     cua: bool
     """Deprecated.
 
     Use mode: 'cua' instead. If both are provided, mode takes precedence.
     """
 
+    execution_model: Annotated[AgentConfigExecutionModel, PropertyInfo(alias="executionModel")]
+    """
+    Model configuration object or model name string (e.g., 'openai/gpt-5-nano') for
+    tool execution (observe/act calls within agent tools). If not specified,
+    inherits from the main model configuration.
+    """
+
     mode: Literal["dom", "hybrid", "cua"]
     """Tool mode for the agent (dom, hybrid, cua). If set, overrides cua."""
 

tests/api_resources/test_sessions.py

@@ -232,6 +232,13 @@ def test_method_execute_with_all_params_overload_1(self, client: Stagehand) -> N
                     "provider": "openai",
                 },
                 "mode": "cua",
+                "model": {
+                    "model_name": "openai/gpt-5-nano",
+                    "api_key": "sk-some-openai-api-key",
+                    "base_url": "https://api.openai.com/v1",
+                    "provider": "openai",
+                },
+                "mode": "cua",
                 "model": {"model_name": "openai/gpt-5-nano"},
                 "provider": "openai",
                 "system_prompt": "systemPrompt",
@@ -321,6 +328,13 @@ def test_method_execute_with_all_params_overload_2(self, client: Stagehand) -> N
                     "provider": "openai",
                 },
                 "mode": "cua",
+                "model": {
+                    "model_name": "openai/gpt-5-nano",
+                    "api_key": "sk-some-openai-api-key",
+                    "base_url": "https://api.openai.com/v1",
+                    "provider": "openai",
+                },
+                "mode": "cua",
                 "model": {"model_name": "openai/gpt-5-nano"},
                 "provider": "openai",
                 "system_prompt": "systemPrompt",
@@ -1077,6 +1091,13 @@ async def test_method_execute_with_all_params_overload_1(self, async_client: Asy
                     "provider": "openai",
                 },
                 "mode": "cua",
+                "model": {
+                    "model_name": "openai/gpt-5-nano",
+                    "api_key": "sk-some-openai-api-key",
+                    "base_url": "https://api.openai.com/v1",
+                    "provider": "openai",
+                },
+                "mode": "cua",
                 "model": {"model_name": "openai/gpt-5-nano"},
                 "provider": "openai",
                 "system_prompt": "systemPrompt",
@@ -1166,6 +1187,13 @@ async def test_method_execute_with_all_params_overload_2(self, async_client: Asy
                     "provider": "openai",
                 },
                 "mode": "cua",
+                "model": {
+                    "model_name": "openai/gpt-5-nano",
+                    "api_key": "sk-some-openai-api-key",
+                    "base_url": "https://api.openai.com/v1",
+                    "provider": "openai",
+                },
+                "mode": "cua",
                 "model": {"model_name": "openai/gpt-5-nano"},
                 "provider": "openai",
                 "system_prompt": "systemPrompt",