Python: [Breaking] Simplified Content types to a single class with classmethod constructors.

python/packages/a2a/agent_framework_a2a/_agent.py

@@ -31,11 +31,8 @@
     AgentThread,
     BaseAgent,
     ChatMessage,
-    Contents,
-    DataContent,
+    Content,
     Role,
-    TextContent,
-    UriContent,
     normalize_messages,
     prepend_agent_framework_to_user_agent,
 )
@@ -333,7 +330,7 @@ def _prepare_message_for_a2a(self, message: ChatMessage) -> A2AMessage:
                         A2APart(
                             root=FilePart(
                                 file=FileWithBytes(
-                                    bytes=_get_uri_data(content.uri),
+                                    bytes=_get_uri_data(content.uri),  # type: ignore[arg-type]
                                     mime_type=content.media_type,
                                 ),
                                 metadata=content.additional_properties,
@@ -362,19 +359,19 @@ def _prepare_message_for_a2a(self, message: ChatMessage) -> A2AMessage:
             metadata=cast(dict[str, Any], message.additional_properties),
         )
 
-    def _parse_contents_from_a2a(self, parts: Sequence[A2APart]) -> list[Contents]:
-        """Parse A2A Parts into Agent Framework Contents.
+    def _parse_contents_from_a2a(self, parts: Sequence[A2APart]) -> list[Content]:
+        """Parse A2A Parts into Agent Framework Content.
 
         Transforms A2A protocol Parts into framework-native Content objects,
         handling text, file (URI/bytes), and data parts with metadata preservation.
         """
-        contents: list[Contents] = []
+        contents: list[Content] = []
         for part in parts:
             inner_part = part.root
             match inner_part.kind:
                 case "text":
                     contents.append(
-                        TextContent(
+                        Content.from_text(
                             text=inner_part.text,
                             additional_properties=inner_part.metadata,
                             raw_representation=inner_part,
@@ -383,7 +380,7 @@ def _parse_contents_from_a2a(self, parts: Sequence[A2APart]) -> list[Contents]:
                 case "file":
                     if isinstance(inner_part.file, FileWithUri):
                         contents.append(
-                            UriContent(
+                            Content.from_uri(
                                 uri=inner_part.file.uri,
                                 media_type=inner_part.file.mime_type or "",
                                 additional_properties=inner_part.metadata,
@@ -392,7 +389,7 @@ def _parse_contents_from_a2a(self, parts: Sequence[A2APart]) -> list[Contents]:
                         )
                     elif isinstance(inner_part.file, FileWithBytes):
                         contents.append(
-                            DataContent(
+                            Content.from_data(
                                 data=base64.b64decode(inner_part.file.bytes),
                                 media_type=inner_part.file.mime_type or "",
                                 additional_properties=inner_part.metadata,
@@ -401,7 +398,7 @@ def _parse_contents_from_a2a(self, parts: Sequence[A2APart]) -> list[Contents]:
                         )
                 case "data":
                     contents.append(
-                        TextContent(
+                        Content.from_text(
                             text=json.dumps(inner_part.data),
                             additional_properties=inner_part.metadata,
                             raw_representation=inner_part,

python/packages/a2a/tests/test_a2a_agent.py

@@ -24,12 +24,8 @@
     AgentResponse,
     AgentResponseUpdate,
     ChatMessage,
-    DataContent,
-    ErrorContent,
-    HostedFileContent,
+    Content,
     Role,
-    TextContent,
-    UriContent,
 )
 from agent_framework.a2a import A2AAgent
 from pytest import fixture, raises
@@ -289,8 +285,8 @@ def test_parse_contents_from_a2a_conversion(a2a_agent: A2AAgent) -> None:
 
     # Verify conversion
     assert len(contents) == 2
-    assert isinstance(contents[0], TextContent)
-    assert isinstance(contents[1], TextContent)
+    assert contents[0].type == "text"
+    assert contents[1].type == "text"
     assert contents[0].text == "First part"
     assert contents[1].text == "Second part"
 
@@ -299,7 +295,7 @@ def test_prepare_message_for_a2a_with_error_content(a2a_agent: A2AAgent) -> None
     """Test _prepare_message_for_a2a with ErrorContent."""
 
     # Create ChatMessage with ErrorContent
-    error_content = ErrorContent(message="Test error message")
+    error_content = Content.from_error(message="Test error message")
     message = ChatMessage(role=Role.USER, contents=[error_content])
 
     # Convert to A2A message
@@ -314,7 +310,7 @@ def test_prepare_message_for_a2a_with_uri_content(a2a_agent: A2AAgent) -> None:
     """Test _prepare_message_for_a2a with UriContent."""
 
     # Create ChatMessage with UriContent
-    uri_content = UriContent(uri="http://example.com/file.pdf", media_type="application/pdf")
+    uri_content = Content.from_uri(uri="http://example.com/file.pdf", media_type="application/pdf")
     message = ChatMessage(role=Role.USER, contents=[uri_content])
 
     # Convert to A2A message
@@ -330,7 +326,7 @@ def test_prepare_message_for_a2a_with_data_content(a2a_agent: A2AAgent) -> None:
     """Test _prepare_message_for_a2a with DataContent."""
 
     # Create ChatMessage with DataContent (base64 data URI)
-    data_content = DataContent(uri="data:text/plain;base64,SGVsbG8gV29ybGQ=", media_type="text/plain")
+    data_content = Content.from_uri(uri="data:text/plain;base64,SGVsbG8gV29ybGQ=", media_type="text/plain")
     message = ChatMessage(role=Role.USER, contents=[data_content])
 
     # Convert to A2A message
@@ -368,7 +364,7 @@ async def test_run_stream_with_message_response(a2a_agent: A2AAgent, mock_a2a_cl
     assert len(updates[0].contents) == 1
 
     content = updates[0].contents[0]
-    assert isinstance(content, TextContent)
+    assert content.type == "text"
     assert content.text == "Streaming response from agent!"
 
     assert updates[0].response_id == "msg-stream-123"
@@ -414,10 +410,10 @@ def test_prepare_message_for_a2a_with_multiple_contents() -> None:
     message = ChatMessage(
         role=Role.USER,
         contents=[
-            TextContent(text="Here's the analysis:"),
-            DataContent(data=b"binary data", media_type="application/octet-stream"),
-            UriContent(uri="https://example.com/image.png", media_type="image/png"),
-            TextContent(text='{"structured": "data"}'),
+            Content.from_text(text="Here's the analysis:"),
+            Content.from_data(data=b"binary data", media_type="application/octet-stream"),
+            Content.from_uri(uri="https://example.com/image.png", media_type="image/png"),
+            Content.from_text(text='{"structured": "data"}'),
         ],
     )
 
@@ -445,7 +441,7 @@ def test_parse_contents_from_a2a_with_data_part() -> None:
 
     assert len(contents) == 1
 
-    assert isinstance(contents[0], TextContent)
+    assert contents[0].type == "text"
     assert contents[0].text == '{"key": "value", "number": 42}'
     assert contents[0].additional_properties == {"source": "test"}
 
@@ -470,7 +466,7 @@ def test_prepare_message_for_a2a_with_hosted_file() -> None:
     # Create message with hosted file content
     message = ChatMessage(
         role=Role.USER,
-        contents=[HostedFileContent(file_id="hosted://storage/document.pdf")],
+        contents=[Content.from_hosted_file(file_id="hosted://storage/document.pdf")],
     )
 
     result = agent._prepare_message_for_a2a(message)  # noqa: SLF001
@@ -507,7 +503,7 @@ def test_parse_contents_from_a2a_with_hosted_file_uri() -> None:
 
     assert len(contents) == 1
 
-    assert isinstance(contents[0], UriContent)
+    assert contents[0].type == "uri"
     assert contents[0].uri == "hosted://storage/document.pdf"
     assert contents[0].media_type == ""  # Converted None to empty string
 

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

@@ -17,12 +17,10 @@
     ChatMessage,
     ChatResponse,
     ChatResponseUpdate,
-    DataContent,
-    FunctionCallContent,
+    Content,
+    use_chat_middleware,
+    use_function_invocation,
 )
-from agent_framework._middleware import use_chat_middleware
-from agent_framework._tools import use_function_invocation
-from agent_framework._types import BaseContent, Contents
 from agent_framework.observability import use_instrumentation
 
 from ._event_converters import AGUIEventConverter
@@ -53,26 +51,11 @@
 logger: logging.Logger = logging.getLogger(__name__)
 
 
-class ServerFunctionCallContent(BaseContent):
-    """Wrapper for server function calls to prevent client re-execution.
-
-    All function calls from the remote server are server-side executions.
-    This wrapper prevents @use_function_invocation from trying to execute them again.
-    """
-
-    function_call_content: FunctionCallContent
-
-    def __init__(self, function_call_content: FunctionCallContent) -> None:
-        """Initialize with the function call content."""
-        super().__init__(type="server_function_call")
-        self.function_call_content = function_call_content
-
-
-def _unwrap_server_function_call_contents(contents: MutableSequence[Contents | dict[str, Any]]) -> None:
-    """Replace ServerFunctionCallContent instances with their underlying call content."""
+def _unwrap_server_function_call_contents(contents: MutableSequence[Content | dict[str, Any]]) -> None:
+    """Replace server_function_call instances with their underlying call content."""
     for idx, content in enumerate(contents):
-        if isinstance(content, ServerFunctionCallContent):
-            contents[idx] = content.function_call_content  # type: ignore[assignment]
+        if content.type == "server_function_call":  # type: ignore[union-attr]
+            contents[idx] = content.function_call  # type: ignore[assignment, union-attr]
 
 
 TBaseChatClient = TypeVar("TBaseChatClient", bound=type[BaseChatClient[Any]])
@@ -93,7 +76,7 @@ def _apply_server_function_call_unwrap(chat_client: TBaseChatClient) -> TBaseCha
     @wraps(original_get_streaming_response)
     async def streaming_wrapper(self, *args: Any, **kwargs: Any) -> AsyncIterable[ChatResponseUpdate]:
         async for update in original_get_streaming_response(self, *args, **kwargs):
-            _unwrap_server_function_call_contents(cast(MutableSequence[Contents | dict[str, Any]], update.contents))
+            _unwrap_server_function_call_contents(cast(MutableSequence[Content | dict[str, Any]], update.contents))
             yield update
 
     chat_client.get_streaming_response = streaming_wrapper  # type: ignore[assignment]
@@ -105,9 +88,7 @@ async def response_wrapper(self, *args: Any, **kwargs: Any) -> ChatResponse:
         response = await original_get_response(self, *args, **kwargs)
         if response.messages:
             for message in response.messages:
-                _unwrap_server_function_call_contents(
-                    cast(MutableSequence[Contents | dict[str, Any]], message.contents)
-                )
+                _unwrap_server_function_call_contents(cast(MutableSequence[Content | dict[str, Any]], message.contents))
         return response
 
     chat_client.get_response = response_wrapper  # type: ignore[assignment]
@@ -289,13 +270,13 @@ def _extract_state_from_messages(
         last_message = messages[-1]
 
         for content in last_message.contents:
-            if isinstance(content, DataContent) and content.media_type == "application/json":
+            if isinstance(content, Content) and content.type == "data" and content.media_type == "application/json":
                 try:
                     uri = content.uri
-                    if uri.startswith("data:application/json;base64,"):
+                    if uri.startswith("data:application/json;base64,"):  # type: ignore[union-attr]
                         import base64
 
-                        encoded_data = uri.split(",", 1)[1]
+                        encoded_data = uri.split(",", 1)[1]  # type: ignore[union-attr]
                         decoded_bytes = base64.b64decode(encoded_data)
                         state = json.loads(decoded_bytes.decode("utf-8"))
 
@@ -433,19 +414,19 @@ async def _inner_get_streaming_response(
                 )
                 # Distinguish client vs server tools
                 for i, content in enumerate(update.contents):
-                    if isinstance(content, FunctionCallContent):
+                    if content.type == "function_call":  # type: ignore[attr-defined]
                         logger.debug(
-                            f"[AGUIChatClient] Function call: {content.name}, in client_tool_set: {content.name in client_tool_set}"
+                            f"[AGUIChatClient] Function call: {content.name}, in client_tool_set: {content.name in client_tool_set}"  # type: ignore[attr-defined]
                         )
-                        if content.name in client_tool_set:
+                        if content.name in client_tool_set:  # type: ignore[attr-defined]
                             # Client tool - let @use_function_invocation execute it
-                            if not content.additional_properties:
-                                content.additional_properties = {}
-                            content.additional_properties["agui_thread_id"] = thread_id
+                            if not content.additional_properties:  # type: ignore[attr-defined]
+                                content.additional_properties = {}  # type: ignore[attr-defined]
+                            content.additional_properties["agui_thread_id"] = thread_id  # type: ignore[attr-defined]
                         else:
                             # Server tool - wrap so @use_function_invocation ignores it
-                            logger.debug(f"[AGUIChatClient] Wrapping server tool: {content.name}")
-                            self._register_server_tool_placeholder(content.name)
-                            update.contents[i] = ServerFunctionCallContent(content)  # type: ignore
+                            logger.debug(f"[AGUIChatClient] Wrapping server tool: {content.name}")  # type: ignore[union-attr]
+                            self._register_server_tool_placeholder(content.name)  # type: ignore[arg-type]
+                            update.contents[i] = Content(type="server_function_call", function_call=content)  # type: ignore
 
                 yield update

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

@@ -6,12 +6,9 @@
 
 from agent_framework import (
     ChatResponseUpdate,
-    ErrorContent,
+    Content,
     FinishReason,
-    FunctionCallContent,
-    FunctionResultContent,
     Role,
-    TextContent,
 )
 
 
@@ -117,7 +114,7 @@ def _handle_text_message_content(self, event: dict[str, Any]) -> ChatResponseUpd
         return ChatResponseUpdate(
             role=Role.ASSISTANT,
             message_id=self.current_message_id,
-            contents=[TextContent(text=delta)],
+            contents=[Content.from_text(text=delta)],
         )
 
     def _handle_text_message_end(self, event: dict[str, Any]) -> ChatResponseUpdate | None:
@@ -133,7 +130,7 @@ def _handle_tool_call_start(self, event: dict[str, Any]) -> ChatResponseUpdate:
         return ChatResponseUpdate(
             role=Role.ASSISTANT,
             contents=[
-                FunctionCallContent(
+                Content.from_function_call(
                     call_id=self.current_tool_call_id or "",
                     name=self.current_tool_name or "",
                     arguments="",
@@ -149,7 +146,7 @@ def _handle_tool_call_args(self, event: dict[str, Any]) -> ChatResponseUpdate:
         return ChatResponseUpdate(
             role=Role.ASSISTANT,
             contents=[
-                FunctionCallContent(
+                Content.from_function_call(
                     call_id=self.current_tool_call_id or "",
                     name=self.current_tool_name or "",
                     arguments=delta,
@@ -170,7 +167,7 @@ def _handle_tool_call_result(self, event: dict[str, Any]) -> ChatResponseUpdate:
         return ChatResponseUpdate(
             role=Role.TOOL,
             contents=[
-                FunctionResultContent(
+                Content.from_function_result(
                     call_id=tool_call_id,
                     result=result,
                 )
@@ -197,7 +194,7 @@ def _handle_run_error(self, event: dict[str, Any]) -> ChatResponseUpdate:
             role=Role.ASSISTANT,
             finish_reason=FinishReason.CONTENT_FILTER,
             contents=[
-                ErrorContent(
+                Content.from_error(
                     message=error_message,
                     error_code="RUN_ERROR",
                 )