Python: [BREAKING] changed AIFunction to FunctionTool and @ai_function to @tool (#3413)

* changed AIFunction to FunctionTool and @ai_function to @tool

* test and mypy fixes

* mypy fix

* switch function tool to always_require

* fix noop

* fix github copilot imports

* test fixes

* fix ollama test

* fixes for tests

* fix tests

* reverted change to always_require and extended timeout

* fix test

python/packages/ag-ui/agent_framework_ag_ui/_client.py

@@ -12,12 +12,12 @@ from typing import TYPE_CHECKING, Any, Generic, cast
 
 import httpx
 from agent_framework import (
-    AIFunction,
     BaseChatClient,
     ChatMessage,
     ChatResponse,
     ChatResponseUpdate,
     Content,
+    FunctionTool,
     use_chat_middleware,
     use_function_invocation,
 )
@@ -239,7 +239,7 @@ class AGUIChatClient(BaseChatClient[TAGUIChatOptions], Generic[TAGUIChatOptions]
         if any(getattr(tool, "name", None) == tool_name for tool in config.additional_tools):
             return
 
-        placeholder: AIFunction[Any, Any] = AIFunction(
+        placeholder: FunctionTool[Any, Any] = FunctionTool(
             name=tool_name,
             description="Server-managed tool placeholder (AG-UI)",
             func=None,

python/packages/ag-ui/agent_framework_ag_ui/_utils.py

@@ -10,7 +10,7 @@ from dataclasses import asdict, is_dataclass
 from datetime import date, datetime
 from typing import Any
 
-from agent_framework import AgentResponseUpdate, AIFunction, ChatResponseUpdate, Role, ToolProtocol
+from agent_framework import AgentResponseUpdate, ChatResponseUpdate, FunctionTool, Role, ToolProtocol
 
 # Role mapping constants
 AGUI_TO_FRAMEWORK_ROLE: dict[str, Role] = {
@@ -160,10 +160,10 @@ def make_json_safe(obj: Any) -> Any:  # noqa: ANN401
 
 def convert_agui_tools_to_agent_framework(
     agui_tools: list[dict[str, Any]] | None,
-) -> list[AIFunction[Any, Any]] | None:
-    """Convert AG-UI tool definitions to Agent Framework AIFunction declarations.
+) -> list[FunctionTool[Any, Any]] | None:
+    """Convert AG-UI tool definitions to Agent Framework FunctionTool declarations.
 
-    Creates declaration-only AIFunction instances (no executable implementation).
+    Creates declaration-only FunctionTool instances (no executable implementation).
     These are used to tell the LLM about available tools. The actual execution
     happens on the client side via @use_function_invocation.
 
@@ -174,18 +174,18 @@ def convert_agui_tools_to_agent_framework(
         agui_tools: List of AG-UI tool definitions with name, description, parameters
 
     Returns:
-        List of AIFunction declarations, or None if no tools provided
+        List of FunctionTool declarations, or None if no tools provided
     """
     if not agui_tools:
         return None
 
-    result: list[AIFunction[Any, Any]] = []
+    result: list[FunctionTool[Any, Any]] = []
     for tool_def in agui_tools:
-        # Create declaration-only AIFunction (func=None means no implementation)
+        # Create declaration-only FunctionTool (func=None means no implementation)
         # When func=None, the declaration_only property returns True,
         # which tells @use_function_invocation to return the function call
         # without executing it (so it can be sent back to the client)
-        func: AIFunction[Any, Any] = AIFunction(
+        func: FunctionTool[Any, Any] = FunctionTool(
             name=tool_def.get("name", ""),
             description=tool_def.get("description", ""),
             func=None,  # CRITICAL: Makes declaration_only=True
@@ -229,24 +229,24 @@ def convert_tools_to_agui_format(
 
     results: list[dict[str, Any]] = []
 
-    for tool in tool_list:
-        if isinstance(tool, dict):
+    for tool_item in tool_list:
+        if isinstance(tool_item, dict):
             # Already in dict format, pass through
-            results.append(tool)  # type: ignore[arg-type]
-        elif isinstance(tool, AIFunction):
-            # Convert AIFunction to AG-UI tool format
+            results.append(tool_item)  # type: ignore[arg-type]
+        elif isinstance(tool_item, FunctionTool):
+            # Convert FunctionTool to AG-UI tool format
             results.append(
                 {
-                    "name": tool.name,
-                    "description": tool.description,
-                    "parameters": tool.parameters(),
+                    "name": tool_item.name,
+                    "description": tool_item.description,
+                    "parameters": tool_item.parameters(),
                 }
             )
-        elif callable(tool):
-            # Convert callable to AIFunction first, then to AG-UI format
-            from agent_framework import ai_function
+        elif callable(tool_item):
+            # Convert callable to FunctionTool first, then to AG-UI format
+            from agent_framework import tool
 
-            ai_func = ai_function(tool)
+            ai_func = tool(tool_item)
             results.append(
                 {
                     "name": ai_func.name,
@@ -254,11 +254,11 @@ def convert_tools_to_agui_format(
                     "parameters": ai_func.parameters(),
                 }
             )
-        elif isinstance(tool, ToolProtocol):
+        elif isinstance(tool_item, ToolProtocol):
             # Handle other ToolProtocol implementations
-            # For now, we'll skip non-AIFunction tools as they may not have
+            # For now, we'll skip non-FunctionTool instances as they may not have
             # the parameters() method. This matches .NET behavior which only
-            # converts AIFunctionDeclaration instances.
+            # converts FunctionToolDeclaration instances.
             continue
 
     return results if results else None

python/packages/ag-ui/agent_framework_ag_ui_examples/README.md

@@ -187,11 +187,11 @@ The package uses a clean, orchestrator-based architecture:
 You can create your own agent factories following the same pattern as the examples:
 
 ```python
-from agent_framework import ChatAgent, ai_function
+from agent_framework import ChatAgent, tool
 from agent_framework import ChatClientProtocol
 from agent_framework.ag_ui import AgentFrameworkAgent
 
-@ai_function
+@tool
 def my_tool(param: str) -> str:
     """My custom tool."""
     return f"Result: {param}"
@@ -294,9 +294,9 @@ wrapped_agent = AgentFrameworkAgent(
 Human-in-the-loop is automatically handled when tools are marked for approval:
 
 ```python
-from agent_framework import ai_function
+from agent_framework import tool
 
-@ai_function(approval_mode="always_require")
+@tool(approval_mode="always_require")
 def sensitive_action(param: str) -> str:
     """This action requires user approval."""
     return f"Executed with {param}"

python/packages/ag-ui/agent_framework_ag_ui_examples/agents/document_writer_agent.py

@@ -2,11 +2,11 @@
 
 """Example agent demonstrating predictive state updates with document writing."""
 
-from agent_framework import ChatAgent, ChatClientProtocol, ai_function
+from agent_framework import ChatAgent, ChatClientProtocol, tool
 from agent_framework.ag_ui import AgentFrameworkAgent
 
 
-@ai_function(approval_mode="always_require")
+@tool(approval_mode="always_require")
 def write_document(document: str) -> str:
     """Write a document. Use markdown formatting to format the document.
 

python/packages/ag-ui/agent_framework_ag_ui_examples/agents/human_in_the_loop_agent.py

@@ -5,7 +5,7 @@
 from enum import Enum
 from typing import Any
 
-from agent_framework import ChatAgent, ChatClientProtocol, ai_function
+from agent_framework import ChatAgent, ChatClientProtocol, tool
 from pydantic import BaseModel, Field
 
 
@@ -23,7 +23,7 @@ class TaskStep(BaseModel):
     status: StepStatus = Field(default=StepStatus.ENABLED, description="Whether the step is enabled or disabled")
 
 
-@ai_function(
+@tool(
     name="generate_task_steps",
     description="Generate execution steps for a task",
     approval_mode="always_require",

python/packages/ag-ui/agent_framework_ag_ui_examples/agents/recipe_agent.py

@@ -5,7 +5,7 @@
 from enum import Enum
 from typing import Any
 
-from agent_framework import ChatAgent, ChatClientProtocol, ai_function
+from agent_framework import ChatAgent, ChatClientProtocol, tool
 from agent_framework.ag_ui import AgentFrameworkAgent
 from pydantic import BaseModel, Field
 
@@ -49,7 +49,7 @@ class Recipe(BaseModel):
     instructions: list[str] = Field(..., description="Step-by-step cooking instructions")
 
 
-@ai_function
+@tool
 def update_recipe(recipe: Recipe) -> str:
     """Update the recipe with new or modified content.
 

python/packages/ag-ui/agent_framework_ag_ui_examples/agents/research_assistant_agent.py

@@ -5,11 +5,11 @@
 import asyncio
 from typing import Any
 
-from agent_framework import ChatAgent, ChatClientProtocol, ai_function
+from agent_framework import ChatAgent, ChatClientProtocol, tool
 from agent_framework.ag_ui import AgentFrameworkAgent
 
 
-@ai_function
+@tool
 async def research_topic(topic: str) -> str:
     """Research a topic and generate a comprehensive report.
 
@@ -35,7 +35,7 @@ async def research_topic(topic: str) -> str:
     return f"Research report on '{topic}':\n" + "\n".join(results)
 
 
-@ai_function
+@tool
 async def create_presentation(title: str, num_slides: int) -> str:
     """Create a presentation with multiple slides.
 
@@ -55,7 +55,7 @@ async def create_presentation(title: str, num_slides: int) -> str:
     return f"Created presentation '{title}' with {num_slides} slides:\n" + "\n".join(slides)
 
 
-@ai_function
+@tool
 async def analyze_data(dataset: str) -> str:
     """Analyze a dataset and produce insights.
 

python/packages/ag-ui/agent_framework_ag_ui_examples/agents/task_planner_agent.py

@@ -4,11 +4,11 @@
 
 from typing import Any
 
-from agent_framework import ChatAgent, ChatClientProtocol, ai_function
+from agent_framework import ChatAgent, ChatClientProtocol, tool
 from agent_framework.ag_ui import AgentFrameworkAgent
 
 
-@ai_function(approval_mode="always_require")
+@tool(approval_mode="always_require")
 def create_calendar_event(title: str, date: str, time: str) -> str:
     """Create a calendar event.
 
@@ -23,7 +23,7 @@ def create_calendar_event(title: str, date: str, time: str) -> str:
     return f"Calendar event '{title}' created for {date} at {time}"
 
 
-@ai_function(approval_mode="always_require")
+@tool(approval_mode="always_require")
 def send_email(to: str, subject: str, body: str) -> str:
     """Send an email.
 
@@ -38,7 +38,7 @@ def send_email(to: str, subject: str, body: str) -> str:
     return f"Email sent to {to} with subject '{subject}'"
 
 
-@ai_function(approval_mode="always_require")
+@tool(approval_mode="always_require")
 def book_meeting_room(room_name: str, date: str, start_time: str, end_time: str) -> str:
     """Book a meeting room.
 

python/packages/ag-ui/agent_framework_ag_ui_examples/agents/task_steps_agent.py

@@ -18,7 +18,7 @@ from ag_ui.core import (
     TextMessageStartEvent,
     ToolCallStartEvent,
 )
-from agent_framework import ChatAgent, ChatClientProtocol, ChatMessage, Content, ai_function
+from agent_framework import ChatAgent, ChatClientProtocol, ChatMessage, Content, tool
 from agent_framework.ag_ui import AgentFrameworkAgent
 from pydantic import BaseModel, Field
 
@@ -39,7 +39,7 @@ class TaskStep(BaseModel):
     status: StepStatus = Field(default=StepStatus.PENDING, description="The status of the step")
 
 
-@ai_function
+@tool
 def generate_task_steps(steps: list[TaskStep]) -> str:
     """Generate a list of task steps for completing a task.
 

python/packages/ag-ui/agent_framework_ag_ui_examples/agents/ui_generator_agent.py

@@ -3,9 +3,9 @@
 """Example agent demonstrating Tool-based Generative UI (Feature 5)."""
 
 import sys
-from typing import Any, TypedDict
+from typing import TYPE_CHECKING, Any, TypedDict
 
-from agent_framework import AIFunction, ChatAgent, ChatClientProtocol, ChatOptions
+from agent_framework import ChatAgent, ChatClientProtocol, FunctionTool
 from agent_framework.ag_ui import AgentFrameworkAgent
 
 if sys.version_info >= (3, 13):
@@ -13,8 +13,11 @@ if sys.version_info >= (3, 13):
 else:
     from typing_extensions import TypeVar  # type: ignore # pragma: no cover
 
+if TYPE_CHECKING:
+    from agent_framework import ChatOptions
+
 # Declaration-only tools (func=None) - actual rendering happens on the client side
-generate_haiku = AIFunction[Any, str](
+generate_haiku = FunctionTool[Any, str](
     name="generate_haiku",
     description="""Generate a haiku with image and gradient background (FRONTEND_RENDER).
 
@@ -62,7 +65,7 @@ generate_haiku = AIFunction[Any, str](
     },
 )
 
-create_chart = AIFunction[Any, str](
+create_chart = FunctionTool[Any, str](
     name="create_chart",
     description="""Create an interactive chart (FRONTEND_RENDER).
 
@@ -90,7 +93,7 @@ create_chart = AIFunction[Any, str](
     },
 )
 
-display_timeline = AIFunction[Any, str](
+display_timeline = FunctionTool[Any, str](
     name="display_timeline",
     description="""Display an interactive timeline (FRONTEND_RENDER).
 
@@ -118,7 +121,7 @@ display_timeline = AIFunction[Any, str](
     },
 )
 
-show_comparison_table = AIFunction[Any, str](
+show_comparison_table = FunctionTool[Any, str](
     name="show_comparison_table",
     description="""Show a comparison table (FRONTEND_RENDER).
 

python/packages/ag-ui/agent_framework_ag_ui_examples/agents/weather_agent.py

@@ -4,10 +4,10 @@
 
 from typing import Any
 
-from agent_framework import ChatAgent, ChatClientProtocol, ai_function
+from agent_framework import ChatAgent, ChatClientProtocol, tool
 
 
-@ai_function
+@tool
 def get_weather(location: str) -> dict[str, Any]:
     """Get the current weather for a location.
 
@@ -39,7 +39,7 @@ def get_weather(location: str) -> dict[str, Any]:
     }
 
 
-@ai_function
+@tool
 def get_forecast(location: str, days: int = 3) -> str:
     """Get the weather forecast for a location.
 

python/packages/ag-ui/getting_started/client_advanced.py

@@ -12,11 +12,11 @@ This example demonstrates advanced AGUIChatClient features including:
 import asyncio
 import os
 
-from agent_framework import ai_function
+from agent_framework import tool
 from agent_framework.ag_ui import AGUIChatClient
 
 
-@ai_function
+@tool
 def get_weather(location: str) -> str:
     """Get the current weather for a location.
 
@@ -33,7 +33,7 @@ def get_weather(location: str) -> str:
     return weather_data.get(location.lower(), f"Weather data not available for {location}")
 
 
-@ai_function
+@tool
 def calculate(a: float, b: float, operation: str) -> str:
     """Perform basic arithmetic operations.
 

python/packages/ag-ui/getting_started/client_with_agent.py

@@ -22,7 +22,7 @@ import asyncio
 import logging
 import os
 
-from agent_framework import ChatAgent, ai_function
+from agent_framework import ChatAgent, tool
 from agent_framework.ag_ui import AGUIChatClient
 
 # Enable debug logging
@@ -33,7 +33,7 @@ logging.basicConfig(
 logger = logging.getLogger(__name__)
 
 
-@ai_function(description="Get the current weather for a location.")
+@tool(description="Get the current weather for a location.")
 def get_weather(location: str) -> str:
     """Get the current weather for a location.
 

python/packages/ag-ui/getting_started/server.py

@@ -5,7 +5,7 @@
 import logging
 import os
 
-from agent_framework import ChatAgent, ai_function
+from agent_framework import ChatAgent, tool
 from agent_framework.ag_ui import add_agent_framework_fastapi_endpoint
 from agent_framework.azure import AzureOpenAIChatClient
 from dotenv import load_dotenv
@@ -87,7 +87,7 @@ async def verify_api_key(api_key: str | None = Security(API_KEY_HEADER)) -> None
 
 
 # Server-side tool (executes on server)
-@ai_function(description="Get the time zone for a location.")
+@tool(description="Get the time zone for a location.")
 def get_time_zone(location: str) -> str:
     """Get the time zone for a location.
 

python/packages/ag-ui/tests/test_ag_ui_client.py

@@ -13,7 +13,7 @@ from agent_framework import (
     ChatResponseUpdate,
     Content,
     Role,
-    ai_function,
+    tool,
 )
 from pytest import MonkeyPatch
 
@@ -231,9 +231,9 @@ class TestAGUIChatClient:
         When server requests a client function, @use_function_invocation decorator
         intercepts and executes it locally. This matches .NET AG-UI implementation.
         """
-        from agent_framework import ai_function
+        from agent_framework import tool
 
-        @ai_function
+        @tool
         def test_tool(param: str) -> str:
             """Test tool."""
             return "result"
@@ -299,7 +299,7 @@ class TestAGUIChatClient:
     async def test_server_tool_calls_not_executed_locally(self, monkeypatch: MonkeyPatch) -> None:
         """Server tools should not trigger local function invocation even when client tools exist."""
 
-        @ai_function
+        @tool
         def client_tool() -> str:
             """Client tool stub."""
             return "client"

python/packages/ag-ui/tests/test_agent_wrapper_comprehensive.py

@@ -680,12 +680,12 @@ async def test_agent_with_use_service_thread_is_true():
 
 async def test_function_approval_mode_executes_tool():
     """Test that function approval with approval_mode='always_require' sends the correct messages."""
-    from agent_framework import ai_function
+    from agent_framework import tool
     from agent_framework.ag_ui import AgentFrameworkAgent
 
     messages_received: list[Any] = []
 
-    @ai_function(
+    @tool(
         name="get_datetime",
         description="Get the current date and time",
         approval_mode="always_require",
@@ -771,12 +771,12 @@ async def test_function_approval_mode_executes_tool():
 
 async def test_function_approval_mode_rejection():
     """Test that function approval rejection creates a rejection response."""
-    from agent_framework import ai_function
+    from agent_framework import tool
     from agent_framework.ag_ui import AgentFrameworkAgent
 
     messages_received: list[Any] = []
 
-    @ai_function(
+    @tool(
         name="delete_all_data",
         description="Delete all user data",
         approval_mode="always_require",

python/packages/ag-ui/tests/test_tooling.py

@@ -2,7 +2,7 @@
 
 from unittest.mock import MagicMock
 
-from agent_framework import ChatAgent, ai_function
+from agent_framework import ChatAgent, tool
 
 from agent_framework_ag_ui._orchestration._tooling import (
     collect_server_tools,
@@ -25,7 +25,7 @@ class MockMCPTool:
         self.is_connected = is_connected
 
 
-@ai_function
+@tool
 def regular_tool() -> str:
     """Regular tool for testing."""
     return "result"
@@ -35,7 +35,7 @@ def _create_chat_agent_with_tool(tool_name: str = "regular_tool") -> ChatAgent:
     """Create a ChatAgent with a mocked chat client and a simple tool.
 
     Note: tool_name parameter is kept for API compatibility but the tool
-    will always be named 'regular_tool' since ai_function uses the function name.
+    will always be named 'regular_tool' since tool uses the function name.
     """
     mock_chat_client = MagicMock()
     return ChatAgent(chat_client=mock_chat_client, tools=[regular_tool])

python/packages/ag-ui/tests/test_utils.py

@@ -252,13 +252,13 @@ def test_make_json_safe_dataclass_with_nested_to_dict_object():
     assert json_str is not None
 
 
-def test_convert_tools_to_agui_format_with_ai_function():
-    """Test converting AIFunction to AG-UI format."""
-    from agent_framework import ai_function
+def test_convert_tools_to_agui_format_with_tool():
+    """Test converting FunctionTool to AG-UI format."""
+    from agent_framework import tool
 
     from agent_framework_ag_ui._utils import convert_tools_to_agui_format
 
-    @ai_function
+    @tool
     def test_func(param: str, count: int = 5) -> str:
         """Test function."""
         return f"{param} {count}"
@@ -318,11 +318,11 @@ def test_convert_tools_to_agui_format_with_none():
 
 def test_convert_tools_to_agui_format_with_single_tool():
     """Test converting single tool (not in list)."""
-    from agent_framework import ai_function
+    from agent_framework import tool
 
     from agent_framework_ag_ui._utils import convert_tools_to_agui_format
 
-    @ai_function
+    @tool
     def single_tool(arg: str) -> str:
         """Single tool."""
         return arg
@@ -336,16 +336,16 @@ def test_convert_tools_to_agui_format_with_single_tool():
 
 def test_convert_tools_to_agui_format_with_multiple_tools():
     """Test converting multiple tools."""
-    from agent_framework import ai_function
+    from agent_framework import tool
 
     from agent_framework_ag_ui._utils import convert_tools_to_agui_format
 
-    @ai_function
+    @tool
     def tool1(x: int) -> int:
         """Tool 1."""
         return x
 
-    @ai_function
+    @tool
     def tool2(y: str) -> str:
         """Tool 2."""
         return y