feat: Add support for Vertex Express Mode API key in AdkApp

PiperOrigin-RevId: 825638989

Author: vertex-sdk-bot

vertexai/agent_engines/templates/adk.py

@@ -557,6 +557,7 @@ def __init__(
             "artifact_service_builder": artifact_service_builder,
             "memory_service_builder": memory_service_builder,
             "instrumentor_builder": instrumentor_builder,
+            "express_mode_api_key": initializer.global_config.api_key,
         }
 
     async def _init_session(
@@ -700,9 +701,18 @@ def set_up(self):
 
         os.environ["GOOGLE_GENAI_USE_VERTEXAI"] = "1"
         project = self._tmpl_attrs.get("project")
-        os.environ["GOOGLE_CLOUD_PROJECT"] = project
+        if project:
+            os.environ["GOOGLE_CLOUD_PROJECT"] = project
         location = self._tmpl_attrs.get("location")
-        os.environ["GOOGLE_CLOUD_LOCATION"] = location
+        if location:
+            os.environ["GOOGLE_CLOUD_LOCATION"] = location
+        express_mode_api_key = self._tmpl_attrs.get("express_mode_api_key")
+        if express_mode_api_key and not project:
+            os.environ["GOOGLE_API_KEY"] = express_mode_api_key
+            # Clear location if project is not set and express mode api key is
+            # provided.
+            os.environ.pop("GOOGLE_CLOUD_LOCATION", None)
+            location = None
 
         # Disable content capture in custom ADK spans unless user enabled
         # tracing explicitly with the old flag
@@ -749,21 +759,37 @@ def set_up(self):
                     VertexAiSessionService,
                 )
 
-                self._tmpl_attrs["session_service"] = VertexAiSessionService(
-                    project=project,
-                    location=location,
-                    agent_engine_id=os.environ.get("GOOGLE_CLOUD_AGENT_ENGINE_ID"),
-                )
+                if is_version_sufficient("1.18.0"):
+                    self._tmpl_attrs["session_service"] = VertexAiSessionService(
+                        project=project,
+                        location=location,
+                        agent_engine_id=os.environ.get("GOOGLE_CLOUD_AGENT_ENGINE_ID"),
+                        express_mode_api_key=express_mode_api_key,
+                    )
+                else:
+                    self._tmpl_attrs["session_service"] = VertexAiSessionService(
+                        project=project,
+                        location=location,
+                        agent_engine_id=os.environ.get("GOOGLE_CLOUD_AGENT_ENGINE_ID"),
+                    )
             except (ImportError, AttributeError):
                 from google.adk.sessions.vertex_ai_session_service_g3 import (
                     VertexAiSessionService,
                 )
 
-                self._tmpl_attrs["session_service"] = VertexAiSessionService(
-                    project=project,
-                    location=location,
-                    agent_engine_id=os.environ.get("GOOGLE_CLOUD_AGENT_ENGINE_ID"),
-                )
+                if is_version_sufficient("1.18.0"):
+                    self._tmpl_attrs["session_service"] = VertexAiSessionService(
+                        project=project,
+                        location=location,
+                        agent_engine_id=os.environ.get("GOOGLE_CLOUD_AGENT_ENGINE_ID"),
+                        express_mode_api_key=express_mode_api_key,
+                    )
+                else:
+                    self._tmpl_attrs["session_service"] = VertexAiSessionService(
+                        project=project,
+                        location=location,
+                        agent_engine_id=os.environ.get("GOOGLE_CLOUD_AGENT_ENGINE_ID"),
+                    )
 
         else:
             self._tmpl_attrs["session_service"] = InMemorySessionService()
@@ -779,11 +805,19 @@ def set_up(self):
                     VertexAiMemoryBankService,
                 )
 
-                self._tmpl_attrs["memory_service"] = VertexAiMemoryBankService(
-                    project=project,
-                    location=location,
-                    agent_engine_id=os.environ.get("GOOGLE_CLOUD_AGENT_ENGINE_ID"),
-                )
+                if is_version_sufficient("1.18.0"):
+                    self._tmpl_attrs["memory_service"] = VertexAiMemoryBankService(
+                        project=project,
+                        location=location,
+                        agent_engine_id=os.environ.get("GOOGLE_CLOUD_AGENT_ENGINE_ID"),
+                        express_mode_api_key=express_mode_api_key,
+                    )
+                else:
+                    self._tmpl_attrs["memory_service"] = VertexAiMemoryBankService(
+                        project=project,
+                        location=location,
+                        agent_engine_id=os.environ.get("GOOGLE_CLOUD_AGENT_ENGINE_ID"),
+                    )
             except (ImportError, AttributeError):
                 # TODO(ysian): Handle this via _g3 import for google3.
                 pass