feat: Create PR agent for ADK github repo

Automatically generate reasonable PR descriptions.

PiperOrigin-RevId: 781078962

contributing/samples/adk_pr_agent/__init__.py

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+# 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

contributing/samples/adk_pr_agent/agent.py

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+# 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.
+
+# pylint: disable=g-importing-member
+
+import os
+
+from google.adk import Agent
+import requests
+
+GITHUB_TOKEN = os.getenv("GITHUB_TOKEN", "")
+if not GITHUB_TOKEN:
+  raise ValueError("GITHUB_TOKEN environment variable not set")
+
+OWNER = os.getenv("OWNER", "google")
+REPO = os.getenv("REPO", "adk-python")
+
+
+def get_github_pr_info_http(pr_number: int) -> str | None:
+  """Fetches information for a GitHub Pull Request by sending direct HTTP requests.
+
+  Args:
+      pr_number (int): The number of the Pull Request.
+
+  Returns:
+      pr_message: A string.
+  """
+  base_url = "https://api.github.com"
+
+  headers = {
+      "Accept": "application/vnd.github+json",
+      "Authorization": f"Bearer {GITHUB_TOKEN}",
+      "X-GitHub-Api-Version": "2022-11-28",
+  }
+
+  pr_message = ""
+
+  # --- 1. Get main PR details ---
+  pr_url = f"{base_url}/repos/{OWNER}/{REPO}/pulls/{pr_number}"
+  print(f"Fetching PR details from: {pr_url}")
+  try:
+    response = requests.get(pr_url, headers=headers)
+    response.raise_for_status()
+    pr_data = response.json()
+    pr_message += f"The PR title is: {pr_data.get('title')}\n"
+  except requests.exceptions.HTTPError as e:
+    print(
+        f"HTTP Error fetching PR details: {e.response.status_code} - "
+        f" {e.response.text}"
+    )
+    return None
+  except requests.exceptions.RequestException as e:
+    print(f"Network or request error fetching PR details: {e}")
+    return None
+  except Exception as e:  # pylint: disable=broad-except
+    print(f"An unexpected error occurred: {e}")
+    return None
+
+  # --- 2. Fetching associated commits (paginated) ---
+  commits_url = pr_data.get(
+      "commits_url"
+  )  # This URL is provided in the initial PR response
+  if commits_url:
+    print("\n--- Associated Commits in this PR: ---")
+    page = 1
+    while True:
+      # GitHub API often uses 'per_page' and 'page' for pagination
+      params = {
+          "per_page": 100,
+          "page": page,
+      }  # Fetch up to 100 commits per page
+      try:
+        response = requests.get(commits_url, headers=headers, params=params)
+        response.raise_for_status()
+        commits_data = response.json()
+
+        if not commits_data:  # No more commits
+          break
+
+        pr_message += "The associated commits are:\n"
+        for commit in commits_data:
+          message = commit.get("commit", {}).get("message", "").splitlines()[0]
+          if message:
+            pr_message += message + "\n"
+
+        # Check for 'Link' header to determine if more pages exist
+        # This is how GitHub's API indicates pagination
+        if "Link" in response.headers:
+          link_header = response.headers["Link"]
+          if 'rel="next"' in link_header:
+            page += 1  # Move to the next page
+          else:
+            break  # No more pages
+        else:
+          break  # No Link header, so probably only one page
+
+      except requests.exceptions.HTTPError as e:
+        print(
+            f"HTTP Error fetching PR commits (page {page}):"
+            f" {e.response.status_code} - {e.response.text}"
+        )
+        break
+      except requests.exceptions.RequestException as e:
+        print(
+            f"Network or request error fetching PR commits (page {page}): {e}"
+        )
+        break
+  else:
+    print("Commits URL not found in PR data.")
+
+  return pr_message
+
+
+system_prompt = """
+You are a helpful assistant to generate reasonable descriptions for pull requests for software engineers.
+
+The descritions should not be too short (e.g.: less than 3 words), or too long (e.g.: more than 30 words).
+
+The generated description should start with `chore`, `docs`, `feat`, `fix`, `test`, or `refactor`.
+`feat` stands for a new feature.
+`fix` stands for a bug fix.
+`chore`, `docs`, `test`, and `refactor` stand for improvements.
+
+Some good descriptions are:
+1. feat: Added implementation for `get_eval_case`, `update_eval_case` and `delete_eval_case` for the local eval sets manager.
+2. feat: Provide inject_session_state as public util method.
+
+Some bad descriptions are:
+1. fix: This fixes bugs.
+2. feat: This is a new feature.
+
+"""
+
+root_agent = Agent(
+    model="gemini-2.0-flash",
+    name="github_pr_agent",
+    description="Generate pull request descriptions for ADK.",
+    instruction=system_prompt,
+)

contributing/samples/adk_pr_agent/main.py

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+# 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.
+
+# pylint: disable=g-importing-member
+
+import asyncio
+import time
+
+import agent
+from google.adk.agents.run_config import RunConfig
+from google.adk.runners import InMemoryRunner
+from google.adk.sessions import Session
+from google.genai import types
+
+
+async def main():
+  app_name = "adk_pr_app"
+  user_id_1 = "adk_pr_user"
+  runner = InMemoryRunner(
+      agent=agent.root_agent,
+      app_name=app_name,
+  )
+  session_11 = await runner.session_service.create_session(
+      app_name=app_name, user_id=user_id_1
+  )
+
+  async def run_agent_prompt(session: Session, prompt_text: str):
+    content = types.Content(
+        role="user", parts=[types.Part.from_text(text=prompt_text)]
+    )
+    final_agent_response_parts = []
+    async for event in runner.run_async(
+        user_id=user_id_1,
+        session_id=session.id,
+        new_message=content,
+        run_config=RunConfig(save_input_blobs_as_artifacts=False),
+    ):
+      if event.content.parts and event.content.parts[0].text:
+        if event.author == agent.root_agent.name:
+          final_agent_response_parts.append(event.content.parts[0].text)
+    print(f"<<<< Agent Final Output: {''.join(final_agent_response_parts)}\n")
+
+  pr_message = agent.get_github_pr_info_http(pr_number=1422)
+  query = "Generate pull request description for " + pr_message
+  await run_agent_prompt(session_11, query)
+
+
+if __name__ == "__main__":
+  start_time = time.time()
+  print(
+      "Script start time:",
+      time.strftime("%Y-%m-%d %H:%M:%S", time.gmtime(start_time)),
+  )
+  print("------------------------------------")
+  asyncio.run(main())
+  end_time = time.time()
+  print("------------------------------------")
+  print(
+      "Script end time:",
+      time.strftime("%Y-%m-%d %H:%M:%S", time.gmtime(end_time)),
+  )
+  print("Total script execution time:", f"{end_time - start_time:.2f} seconds")