diff --git a/src/google/adk/a2a/converters/test_EventConverterConvertA2ATaskToEvent.py b/src/google/adk/a2a/converters/test_EventConverterConvertA2ATaskToEvent.py
new file mode 100644
index 0000000000..bd6f7adc91
--- /dev/null
+++ b/src/google/adk/a2a/converters/test_EventConverterConvertA2ATaskToEvent.py
@@ -0,0 +1,121 @@
+# ********RoostGPT********
+"""
+Test generated by RoostGPT for test unit-adk-python using AI Type Azure Open AI and AI Model gpt-5
+
+ROOST_METHOD_HASH=convert_a2a_task_to_event_40cb3ce258
+ROOST_METHOD_SIG_HASH=convert_a2a_task_to_event_124ed678ea
+
+
+Scenario 1: Rejects None Task Input
+Details:
+  TestName: test_none_task_raises_value_error
+  Description: Verifies that passing None as a2a_task raises ValueError, enforcing required input.
+Execution:
+  Arrange: No setup needed beyond preparing a None task reference.
+  Act: Call convert_a2a_task_to_event(a2a_task=None).
+  Assert: Expect ValueError with message "A2A task cannot be None".
+Validation:
+  Ensures input validation is enforced as specified, preventing undefined behavior and aligning with the function’s documented contract.
+
+"""
+
+# ********RoostGPT********
+from __future__ import annotations
+
+import importlib
+import logging
+import sys
+import unittest
+import uuid
+from collections.abc import Callable
+from datetime import datetime, timezone
+from typing import Any, Dict, List, Optional
+
+# Third-party or project-specific imports that may or may not exist in the environment.
+# These imports are included to align with the provided instructions.
+try:
+    A2AEvent = importlib.import_module("a2a.server.events")
+except Exception:  # pragma: no cover
+    A2AEvent = None
+
+try:
+    # Attempt to import selected types; if unavailable, proceed as tests don't depend on them directly.
+    from a2a.types import DataPart, Message, Role, Task, TaskState, TaskStatus, TaskStatusUpdateEvent, TextPart
+except Exception:  # pragma: no cover
+    DataPart = Message = Role = Task = TaskState = TaskStatus = TaskStatusUpdateEvent = TextPart = None  # type: ignore[assignment]
+
+try:
+    genai_types = importlib.import_module("google.genai")
+except Exception:  # pragma: no cover
+    genai_types = None
+
+try:
+    InvocationContext = importlib.import_module("agents.invocation_context").InvocationContext  # type: ignore[attr-defined]
+except Exception:  # pragma: no cover
+    InvocationContext = None  # type: ignore[assignment]
+
+try:
+    Event = importlib.import_module("events.event").Event  # type: ignore[attr-defined]
+except Exception:  # pragma: no cover
+    Event = None  # type: ignore[assignment]
+
+try:
+    REQUEST_EUC_FUNCTION_CALL_NAME = importlib.import_module("flows.llm_flows.functions").REQUEST_EUC_FUNCTION_CALL_NAME  # type: ignore[attr-defined]
+except Exception:  # pragma: no cover
+    REQUEST_EUC_FUNCTION_CALL_NAME = None  # type: ignore[assignment]
+
+try:
+    a2a_experimental = importlib.import_module("experimental.a2a_experimental")  # type: ignore[attr-defined]
+except Exception:  # pragma: no cover
+    a2a_experimental = None  # type: ignore[assignment]
+
+try:
+    from part_converter import (
+        A2A_DATA_PART_METADATA_IS_LONG_RUNNING_KEY,
+        A2A_DATA_PART_METADATA_TYPE_FUNCTION_CALL,
+        A2A_DATA_PART_METADATA_TYPE_KEY,
+        A2APartToGenAIPartConverter,
+        convert_a2a_part_to_genai_part,
+        convert_genai_part_to_a2a_part,
+        GenAIPartToA2APartConverter,
+    )
+except Exception:  # pragma: no cover
+    A2A_DATA_PART_METADATA_IS_LONG_RUNNING_KEY = None  # type: ignore[assignment]
+    A2A_DATA_PART_METADATA_TYPE_FUNCTION_CALL = None  # type: ignore[assignment]
+    A2A_DATA_PART_METADATA_TYPE_KEY = None  # type: ignore[assignment]
+    A2APartToGenAIPartConverter = None  # type: ignore[assignment]
+    convert_a2a_part_to_genai_part = None  # type: ignore[assignment]
+    convert_genai_part_to_a2a_part = None  # type: ignore[assignment]
+    GenAIPartToA2APartConverter = None  # type: ignore[assignment]
+
+try:
+    _get_adk_metadata_key = importlib.import_module("utils")._get_adk_metadata_key  # type: ignore[attr-defined]
+except Exception:  # pragma: no cover
+    _get_adk_metadata_key = None  # type: ignore[assignment]
+
+# Import the function under test as requested.
+from src.google.adk.a2a.converters.event_converter import convert_a2a_task_to_event
+
+
+def tag(*labels: str):
+    """Simple decorator to attach tags to test methods."""
+    def decorator(func):
+        setattr(func, "tags", labels)
+        return func
+    return decorator
+
+
+class Test_EventConverterConvertA2ATaskToEvent(unittest.TestCase):
+    @tag("smoke", "regression", "negative", "invalid")
+    def test_none_task_raises_value_error(self):
+        # Arrange
+        a2a_task = None
+
+        # Act / Assert
+        with self.assertRaisesRegex(ValueError, r"^A2A task cannot be None$"):
+            convert_a2a_task_to_event(a2a_task=a2a_task)
+
+
+if __name__ == "__main__":
+    # TODO: Adjust verbosity if needed for your test environment
+    unittest.main(verbosity=2)
diff --git a/src/google/adk/a2a/requirements-roost.txt b/src/google/adk/a2a/requirements-roost.txt
new file mode 100644
index 0000000000..d18d252c77
--- /dev/null
+++ b/src/google/adk/a2a/requirements-roost.txt
@@ -0,0 +1,15 @@
+
+agents
+artifacts
+auth
+events
+flows
+memory
+protobuf
+pydantic
+runners
+starlette
+tools
+typing_extensions
+pytest
+auto_mix_prep
\ No newline at end of file