feat: Add Easy GCP support to ADK CLI

src/google/adk/cli/cli_create.py

@@ -22,6 +22,7 @@
 import click
 
 from ..apps.app import validate_app_name
+from .utils import gcp_utils
 
 _INIT_PY_TEMPLATE = """\
 from . import agent
@@ -61,18 +62,36 @@
 https://google.github.io/adk-docs/agents/models
 """
 
+_EXPRESS_TOS_MSG = """
+Google Cloud Express Mode Terms of Service: https://cloud.google.com/terms/google-cloud-express
+By continuing, you agree to the Terms of Service for Vertex AI Express Mode.
+Would you like to proceed? (yes/no)
+"""
+
+_NOT_ELIGIBLE_MSG = """
+You are not eligible for Express Mode.
+Please follow these instructions to set up a full Google Cloud project:
+https://google.github.io/adk-docs/get-started/quickstart/#gemini---google-cloud-vertex-ai
+"""
+
 _SUCCESS_MSG_CODE = """
 Agent created in {agent_folder}:
 - .env
 - __init__.py
 - agent.py
+
+⚠️  WARNING: Secrets (like GOOGLE_API_KEY) are stored in .env.
+Please ensure .env is added to your .gitignore to avoid committing secrets to version control.
 """
 
 _SUCCESS_MSG_CONFIG = """
 Agent created in {agent_folder}:
 - .env
 - __init__.py
 - root_agent.yaml
+
+⚠️  WARNING: Secrets (like GOOGLE_API_KEY) are stored in .env.
+Please ensure .env is added to your .gitignore to avoid committing secrets to version control.
 """
 
 
@@ -187,10 +206,10 @@ def _generate_files(
 
   with open(dotenv_file_path, "w", encoding="utf-8") as f:
     lines = []
-    if google_api_key:
-      lines.append("GOOGLE_GENAI_USE_VERTEXAI=0")
-    elif google_cloud_project and google_cloud_region:
+    if google_cloud_project and google_cloud_region:
       lines.append("GOOGLE_GENAI_USE_VERTEXAI=1")
+    elif google_api_key:
+      lines.append("GOOGLE_GENAI_USE_VERTEXAI=0")
     if google_api_key:
       lines.append(f"GOOGLE_API_KEY={google_api_key}")
     if google_cloud_project:
@@ -247,18 +266,110 @@ def _prompt_to_choose_backend(
     A tuple of (google_api_key, google_cloud_project, google_cloud_region).
   """
   backend_choice = click.prompt(
-      "1. Google AI\n2. Vertex AI\nChoose a backend",
-      type=click.Choice(["1", "2"]),
+      "1. Google AI\n2. Vertex AI\n3. Login with Google\nChoose a backend",
+      type=click.Choice(["1", "2", "3"]),
   )
   if backend_choice == "1":
     google_api_key = _prompt_for_google_api_key(google_api_key)
   elif backend_choice == "2":
     click.secho(_GOOGLE_CLOUD_SETUP_MSG, fg="green")
     google_cloud_project = _prompt_for_google_cloud(google_cloud_project)
     google_cloud_region = _prompt_for_google_cloud_region(google_cloud_region)
+  elif backend_choice == "3":
+    google_api_key, google_cloud_project, google_cloud_region = (
+        _handle_login_with_google()
+    )
   return google_api_key, google_cloud_project, google_cloud_region
 
 
+def _handle_login_with_google() -> (
+    Tuple[Optional[str], Optional[str], Optional[str]]
+):
+  """Handles the "Login with Google" flow."""
+  if not gcp_utils.check_adc():
+    click.secho(
+        "No Application Default Credentials found. "
+        "Opening browser for login...",
+        fg="yellow",
+    )
+    try:
+      gcp_utils.login_adc()
+    except RuntimeError as e:
+      click.secho(str(e), fg="red")
+      raise click.Abort()
+
+  # Check for existing Express project
+  express_project = gcp_utils.retrieve_express_project()
+  if express_project:
+    api_key = express_project.get("api_key")
+    project_id = express_project.get("project_id")
+    region = express_project.get("region", "us-central1")
+    if project_id:
+      click.secho(f"Using existing Express project: {project_id}", fg="green")
+      return api_key, project_id, region
+
+  # Check for existing full GCP projects
+  projects = gcp_utils.list_gcp_projects(limit=20)
+  if projects:
+    click.secho("Recently created Google Cloud projects found:", fg="green")
+    click.echo("0. Enter project ID manually")
+    for i, (p_id, p_name) in enumerate(projects, 1):
+      click.echo(f"{i}. {p_name} ({p_id})")
+
+    project_index = click.prompt(
+        "Select a project",
+        type=click.IntRange(0, len(projects)),
+    )
+    if project_index == 0:
+      selected_project_id = _prompt_for_google_cloud(None)
+    else:
+      selected_project_id = projects[project_index - 1][0]
+    region = _prompt_for_google_cloud_region(None)
+    return None, selected_project_id, region
+  else:
+    if click.confirm(
+        "No projects found automatically. Would you like to enter one"
+        " manually?",
+        default=False,
+    ):
+      selected_project_id = _prompt_for_google_cloud(None)
+      region = _prompt_for_google_cloud_region(None)
+      return None, selected_project_id, region
+
+  # Check Express eligibility
+  if gcp_utils.check_express_eligibility():
+    click.secho(_EXPRESS_TOS_MSG, fg="yellow")
+    if click.confirm("Do you accept the Terms of Service?", default=False):
+      selected_region = click.prompt(
+          """\
+Choose a region for Express Mode:
+1. us-central1
+2. europe-west1
+3. asia-southeast1
+Choose region""",
+          type=click.Choice(["1", "2", "3"]),
+          default="1",
+      )
+      region_map = {
+          "1": "us-central1",
+          "2": "europe-west1",
+          "3": "asia-southeast1",
+      }
+      region = region_map[selected_region]
+      express_info = gcp_utils.sign_up_express(location=region)
+      api_key = express_info.get("api_key")
+      project_id = express_info.get("project_id")
+      region = express_info.get("region", region)
+      click.secho(
+          f"Express Mode project created: {project_id}",
+          fg="green",
+      )
+      return api_key, project_id, region
+
+  click.secho(_NOT_ELIGIBLE_MSG, fg="red")
+  raise click.Abort()
+
+
 def _prompt_to_choose_type() -> str:
   """Prompts user to choose type of agent to create."""
   type_choice = click.prompt(

src/google/adk/cli/utils/gcp_utils.py

@@ -0,0 +1,176 @@
+# Copyright 2026 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.
+
+"""Utilities for GCP authentication and Vertex AI Express Mode."""
+
+from __future__ import annotations
+
+import subprocess
+from typing import Any
+from typing import Dict
+from typing import List
+from typing import Optional
+from typing import Tuple
+
+import google.auth
+import google.auth.exceptions
+from google.auth.transport.requests import AuthorizedSession
+from google.auth.transport.requests import Request
+from google.cloud import resourcemanager_v3
+import requests
+
+# TODO: Update to production endpoint before making this public.
+_STAGING_ENDPOINT = (
+    "https://{location}-staging-aiplatform.sandbox.googleapis.com/v1beta1"
+)
+
+
+def check_adc() -> bool:
+  """Checks if Application Default Credentials exist."""
+  try:
+    google.auth.default()
+    return True
+  except google.auth.exceptions.DefaultCredentialsError:
+    return False
+
+
+def login_adc() -> None:
+  """Prompts user to login via gcloud ADC."""
+  try:
+    subprocess.run(
+        ["gcloud", "auth", "application-default", "login"], check=True
+    )
+  except (subprocess.CalledProcessError, FileNotFoundError):
+    raise RuntimeError(
+        "gcloud is not installed or failed to run. "
+        "Please install gcloud to login to Application Default Credentials."
+    )
+
+
+def get_access_token() -> str:
+  """Gets the ADC access token."""
+  try:
+    credentials, _ = google.auth.default()
+    if not credentials.valid:
+      credentials.refresh(Request())
+    return credentials.token or ""
+  except google.auth.exceptions.DefaultCredentialsError:
+    raise RuntimeError("Application Default Credentials not found.")
+
+
+def _call_vertex_express_api(
+    method: str,
+    action: str,
+    location: str = "us-central1",
+    data: Optional[Dict[str, Any]] = None,
+    params: Optional[Dict[str, Any]] = None,
+) -> Dict[str, Any]:
+  """Calls a Vertex AI Express API."""
+  credentials, _ = google.auth.default()
+  session = AuthorizedSession(credentials)
+  url = f"{_STAGING_ENDPOINT.format(location=location)}/vertexExpress{action}"
+  headers = {
+      "Content-Type": "application/json",
+  }
+
+  if method == "GET":
+    response = session.get(url, headers=headers, params=params)
+  elif method == "POST":
+    response = session.post(url, headers=headers, json=data, params=params)
+  else:
+    raise ValueError(f"Unsupported method: {method}")
+
+  response.raise_for_status()
+  return response.json()
+
+
+def retrieve_express_project(
+    location: str = "us-central1",
+) -> Optional[Dict[str, Any]]:
+  """Retrieves existing Express project info."""
+  try:
+    response = _call_vertex_express_api(
+        "GET",
+        ":retrieveExpressProject",
+        location=location,
+        params={"get_default_api_key": True},
+    )
+    project = response.get("expressProject")
+    if not project:
+      return None
+
+    return {
+        "project_id": project.get("projectId"),
+        "api_key": project.get("defaultApiKey"),
+        "region": project.get("region", location),
+    }
+  except requests.exceptions.HTTPError as e:
+    if e.response.status_code == 404:
+      return None
+    raise
+
+
+def check_express_eligibility(
+    location: str = "us-central1",
+) -> bool:
+  """Checks if user is eligible for Express Mode."""
+  try:
+    result = _call_vertex_express_api(
+        "GET", "/Eligibility:check", location=location
+    )
+    return result.get("eligibility") == "IN_SCOPE"
+  except (requests.exceptions.HTTPError, KeyError) as e:
+    return False
+
+
+def sign_up_express(
+    location: str = "us-central1",
+) -> Dict[str, Any]:
+  """Signs up for Express Mode."""
+  project = _call_vertex_express_api(
+      "POST",
+      ":signUp",
+      location=location,
+      data={"region": location, "tos_accepted": True},
+  )
+  return {
+      "project_id": project.get("projectId"),
+      "api_key": project.get("defaultApiKey"),
+      "region": project.get("region", location),
+  }
+
+
+def list_gcp_projects(limit: int = 20) -> List[Tuple[str, str]]:
+  """Lists GCP projects available to the user.
+
+  Args:
+    limit: The maximum number of projects to return.
+
+  Returns:
+    A list of (project_id, name) tuples.
+  """
+  try:
+    client = resourcemanager_v3.ProjectsClient()
+    search_results = client.search_projects()
+
+    projects = []
+    for project in search_results:
+      if len(projects) >= limit:
+        break
+      projects.append(
+          (project.project_id, project.display_name or project.project_id)
+      )
+    return projects
+  except Exception:
+    return []