diff --git a/contributing/samples/pubsub_publisher/__init__.py b/contributing/samples/pubsub_publisher/__init__.py
new file mode 100644
index 000000000..44f7dab56
--- /dev/null
+++ b/contributing/samples/pubsub_publisher/__init__.py
@@ -0,0 +1,15 @@
+# Copyright 2025 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from . import agent
\ No newline at end of file
diff --git a/contributing/samples/pubsub_publisher/agent.py b/contributing/samples/pubsub_publisher/agent.py
new file mode 100644
index 000000000..353a1fd91
--- /dev/null
+++ b/contributing/samples/pubsub_publisher/agent.py
@@ -0,0 +1,116 @@
+# Copyright 2025 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# --- Imports ---
+# Vertex Agent Modules
+from google.adk.agents import Agent # Base class for creating agents
+
+
+# Other Python Modules
+import warnings # For suppressing warnings
+import logging # For controlling logging output
+from dotenv import load_dotenv # For loading environment variables from a .env file
+
+
+# Modules for Publishing Events to GCP Pub/Sub
+import json # For working with JSON data, such as sending events to Pub/Sub
+import uuid # For generating unique identifiers used for idempotency in event publishing
+from typing import Optional # For type hinting optional parameters for gcp_project_id and pubsub_topic_id
+from google.adk.tools import publish_event # For publishing events to Pub/Sub (not used in this script, but included for completeness)
+
+
+# --- Configuration ---
+load_dotenv()
+
+
+# Ignore all warnings
+warnings.filterwarnings("ignore")
+# Set logging level to ERROR to suppress informational messages
+logging.basicConfig(level=logging.INFO)
+
+
+# --- Agent Tool Definitions ---
+
+# Tool function to publish an event to GCP Pub/Sub
+def publish_to_gcp_pubsub_tool(
+    event_data_json: str,
+    event_type: str = "custom_agent_event",
+    gcp_project_id: Optional[str] = 'YOUR_GCP_PROJECT_ID', # If gcp_project_id is not provided, it will use the environment variable GOOGLE_CLOUD_PROJECT
+    pubsub_topic_id: Optional[str] = 'YOUR_PUBSUB_TOPIC_ID' # If pubsub_topic_id is not provided, it will use the environment variable PUBSUB_TOPIC_ID
+) -> str:
+    """
+    Publishes a structured event from the agent to a GCP Pub/Sub topic.
+    The agent should provide the event data as a JSON string.
+    Optionally, gcp_project_id and pubsub_topic_id can be provided to override environment settings.
+
+    Args:
+        event_data_json: A JSON string representing the structured data for the event.
+        event_type: A string to categorize the event (e.g., 'decision_made', 'action_taken').
+        gcp_project_id: The Google Cloud project ID. If not provided, uses the environment variable.
+        pubsub_topic_id: The Pub/Sub topic ID. If not provided, uses the environment variable.
+    """
+    try:
+        event_data = json.loads(event_data_json)
+        event_data["app_message_id"] = str(uuid.uuid4())
+        publish_event(
+            event_data=event_data,
+            event_type=event_type,
+            gcp_project_id=gcp_project_id,
+            pubsub_topic_id=pubsub_topic_id
+        )
+        return f"Event (type: {event_type}) with data '{event_data_json}' has been queued for publishing."
+    except json.JSONDecodeError:
+        return "Error: The provided event_data_json was not valid JSON."
+    except Exception as e:
+        print(f"[AgentTool ERROR] Error attempting to publish event to GCP Pub/Sub: {e}")
+        return f"Error attempting to publish event to GCP Pub/Sub: {str(e)}"
+
+
+
+# --- Root Agent Definition ---
+# @title Define the Root Agent
+
+# Initialize root agent variables
+root_agent = None
+runner_root = None # Initialize runner variable (although runner is created later)
+
+    # Define the root agent (coordinator)
+root_agent = Agent(
+    name="root_support_agent",    # Name for the root agent
+    model="gemini-2.5-flash", # Model for the root agent (orchestration)
+    description="The main coordinator agent. Handles user requests and delegates tasks to specialist sub-agents and tools.", 
+    instruction=                  # The core instructions defining the workflow
+    """
+        You are the lead support coordinator agent. Your goal is to understand the customer's question or topic and provide insightful answers.
+
+        You have access to specialized tools and sub-agents:
+        1. Tool `publish_to_gcp_pubsub_tool`: Use this tool to publish information to GCP Pub/Sub.
+        
+      
+
+        Your workflow:
+        1. You will be provided with a request from a user.
+        2. Inform the user you will begin the research (e.g., "Okay, I'll start researching that for you. Please wait a moment.").
+        3. For key findings, use `publish_to_gcp_pubsub_tool` with `event_type="key_finding_identified"` and `event_data_json` containing the finding details in JSON format.
+        4. Provide a summary of the research findings to the user.
+
+       
+    """,
+    tools=[
+        publish_to_gcp_pubsub_tool, # Tool to publish events to GCP Pub/Sub
+    ],
+    sub_agents=[
+    ],
+
+)
diff --git a/contributing/samples/pubsub_publisher/main.py b/contributing/samples/pubsub_publisher/main.py
new file mode 100755
index 000000000..e38f3fbaa
--- /dev/null
+++ b/contributing/samples/pubsub_publisher/main.py
@@ -0,0 +1,66 @@
+# Copyright 2025 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import asyncio
+import time
+import warnings
+
+import agent
+from dotenv import load_dotenv
+from google.adk import Runner
+from google.adk.artifacts import InMemoryArtifactService
+from google.adk.cli.utils import logs
+from google.adk.sessions import InMemorySessionService
+from google.adk.sessions import Session
+from google.genai import types
+
+load_dotenv(override=True)
+warnings.filterwarnings('ignore', category=UserWarning)
+logs.log_to_tmp_folder()
+
+
+async def main():
+  app_name = 'my_app'
+  user_id_1 = 'user1'
+  session_service = InMemorySessionService()
+  artifact_service = InMemoryArtifactService()
+  runner = Runner(
+      app_name=app_name,
+      agent=agent.root_agent,
+      artifact_service=artifact_service,
+      session_service=session_service,
+  )
+  session_11 = await session_service.create_session(app_name=app_name, user_id=user_id_1)
+
+  async def run_prompt(session: Session, new_message: str):
+    content = types.Content(
+        role='user', parts=[types.Part.from_text(text=new_message)]
+    )
+    print('** User says:', content.model_dump(exclude_none=True))
+    async for event in runner.run_async(
+        user_id=user_id_1,
+        session_id=session.id,
+        new_message=content,
+    ):
+      if event.content.parts and event.content.parts[0].text:
+        print(f'** {event.author}: {event.content.parts[0].text}')
+
+  print('------------------------------------')
+  await run_prompt(session_11, 'Give me a summary of the first moon landing.')
+
+  print('------------------------------------')
+
+
+if __name__ == '__main__':
+  asyncio.run(main())
diff --git a/src/google/adk/tools/pubsub_publisher.py b/src/google/adk/tools/pubsub_publisher.py
new file mode 100644
index 000000000..cf74ba189
--- /dev/null
+++ b/src/google/adk/tools/pubsub_publisher.py
@@ -0,0 +1,116 @@
+# Copyright 2025 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import json
+import asyncio
+import os
+import datetime
+from typing import Dict, Any, Optional
+
+try:
+    from google.cloud import pubsub_v1
+    from google.auth.exceptions import DefaultCredentialsError
+except ImportError:
+    pubsub_v1 = None
+    DefaultCredentialsError = None
+    print("[PubSubPublisher WARNING] google-cloud-pubsub not installed. Pub/Sub features will be unavailable.")
+
+
+_loop: Optional[asyncio.AbstractEventLoop] = None
+_pubsub_publisher: Optional[Any] = None
+_pubsub_topic_path: Optional[str] = None
+_pubsub_enabled: bool = False
+
+def _pubsub_callback(future: Any) -> None:
+    """Callback for Pub/Sub publish results."""
+    try:
+        message_id = future.result()
+        print(f"[PubSubPublisher INFO] Published Pub/Sub message with ID: {message_id}")
+    except Exception as e:
+        print(f"[PubSubPublisher ERROR] Failed to publish Pub/Sub message: {e}")
+
+def setup_pubsub_publisher_async(
+    gcp_project_id: Optional[str] = None,
+    pubsub_topic_id: Optional[str] = None
+) -> None:
+    """
+    Initializes the GCP Pub/Sub publisher.
+    Uses provided arguments or falls back to environment variables.
+    """
+    global _loop, _pubsub_publisher, _pubsub_topic_path, _pubsub_enabled
+
+    _loop = asyncio.get_running_loop()
+
+    if pubsub_v1 is None:
+        print("[PubSubPublisher INFO] GCP Pub/Sub client library not found. Publishing disabled.")
+        _pubsub_enabled = False
+        return
+
+    # Use provided args or get from environment
+    project_id = gcp_project_id or os.environ.get("GOOGLE_CLOUD_PROJECT")
+    topic_id = pubsub_topic_id or os.environ.get("PUBSUB_TOPIC_ID")
+
+    if project_id and topic_id:
+        try:
+            _pubsub_publisher = pubsub_v1.PublisherClient()
+            _pubsub_topic_path = _pubsub_publisher.topic_path(project_id, topic_id)
+            _pubsub_enabled = True
+            print(f"[PubSubPublisher] GCP Pub/Sub publishing enabled for topic: {_pubsub_topic_path}")
+        except DefaultCredentialsError:
+            print("[PubSubPublisher ERROR] GCP Default Credentials not found. Publishing disabled.")
+            _pubsub_enabled = False
+        except Exception as e:
+            print(f"[PubSubPublisher ERROR] Failed to initialize GCP Pub/Sub publisher: {e}. Publishing disabled.")
+            _pubsub_enabled = False
+    else:
+        print("[PubSubPublisher INFO] GOOGLE_CLOUD_PROJECT and/or PUBSUB_TOPIC_ID not set. Publishing disabled.")
+        _pubsub_enabled = False
+
+def publish_event(
+    event_data: Dict[str, Any],
+    event_type: str = "custom_event",
+    gcp_project_id: Optional[str] = None,
+    pubsub_topic_id: Optional[str] = None
+) -> None:
+    """
+    Publishes a structured event to the configured GCP Pub/Sub topic.
+    """
+    if not _pubsub_enabled:
+        setup_pubsub_publisher_async(gcp_project_id=gcp_project_id, pubsub_topic_id=pubsub_topic_id)
+
+    if not _pubsub_enabled or _pubsub_publisher is None or _pubsub_topic_path is None or _loop is None:
+        return
+
+    timestamp = datetime.datetime.utcnow().isoformat() + "Z"
+
+    payload = {
+        "event_type": event_type,
+        "timestamp": timestamp,
+        "data": event_data,
+    }
+
+    try:
+        data_bytes = json.dumps(payload).encode("utf-8")
+
+        def do_publish():
+            try:
+                publish_future = _pubsub_publisher.publish(_pubsub_topic_path, data_bytes)
+                publish_future.add_done_callback(_pubsub_callback)
+            except Exception as e:
+                print(f"[PubSubPublisher ERROR] Error when trying to initiate publish: {e}")
+
+        _loop.call_soon_threadsafe(do_publish)
+
+    except Exception as e:
+        print(f"[PubSubPublisher ERROR] Failed to prepare event for publishing: {e}")