chore: import upstream snapshot with attribution

tests/remote/triggers/test_agent/Dockerfile

@@ -0,0 +1,24 @@
+FROM python:3.11-slim
+
+WORKDIR /app
+
+# Install the local ADK wheel (built from the repo under test).
+# Install the .whl file directly so pip uses it instead of PyPI.
+# Dependencies are resolved from PyPI automatically.
+COPY wheels/ /tmp/wheels/
+SHELL ["/bin/bash", "-c"]
+RUN pip install --no-cache-dir /tmp/wheels/google_adk-*.whl \
+    && rm -rf /tmp/wheels
+
+# Copy the agent into the expected adk layout:
+#   /app/agents/trigger_echo_agent/__init__.py
+#   /app/agents/trigger_echo_agent/agent.py
+COPY __init__.py agents/trigger_echo_agent/__init__.py
+COPY agent.py    agents/trigger_echo_agent/agent.py
+
+ENV PORT=8080
+ENV HOST=0.0.0.0
+
+EXPOSE 8080
+
+CMD ["adk", "api_server", "--host=0.0.0.0", "--port=8080", "--trigger_sources=pubsub,eventarc", "/app/agents"]

tests/remote/triggers/test_agent/__init__.py

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+# 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.

tests/remote/triggers/test_agent/agent.py

@@ -0,0 +1,86 @@
+# 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.
+
+"""Echo agent for remote trigger integration tests.
+
+Uses a before_model_callback to echo user input without calling the LLM,
+making tests fast, deterministic, and free of LLM model quota usage.
+
+Supports optional 429 simulation via the SIMULATE_429_COUNT environment
+variable: when set to N > 0, the first N invocations per session will raise
+a RuntimeError containing "429 RESOURCE_EXHAUSTED" before succeeding.
+"""
+
+import os
+
+from google.adk.agents.callback_context import CallbackContext
+from google.adk.agents.llm_agent import Agent
+from google.adk.models.llm_request import LlmRequest
+from google.adk.models.llm_response import LlmResponse
+from google.genai import types
+
+# Track 429 simulation state across invocations within a process.
+# Keyed by session_id to allow per-session failure counts.
+_429_counter: dict[str, int] = {}
+
+
+def before_model_callback(
+    callback_context: CallbackContext,
+    llm_request: LlmRequest,
+) -> LlmResponse:
+  """Echo user input back without calling the LLM.
+
+  If SIMULATE_429_COUNT is set, raises a transient error for the first N
+  invocations (per session) to exercise the retry-with-backoff logic in
+  the trigger endpoints.
+  """
+  fail_count = int(os.environ.get("SIMULATE_429_COUNT", "0"))
+  session = callback_context.session
+  session_id = session.id if session else "default"
+
+  if fail_count > 0:
+    current = _429_counter.get(session_id, 0)
+    if current < fail_count:
+      _429_counter[session_id] = current + 1
+      raise RuntimeError("429 RESOURCE_EXHAUSTED: simulated quota exceeded")
+
+  # Extract the most recent user message from the session events.
+  user_text = ""
+  if session and session.events:
+    for event in reversed(session.events):
+      if event.content and event.content.role == "user" and event.content.parts:
+        user_text = event.content.parts[0].text or ""
+        break
+
+  # Fall back to the current LLM request contents if no session event found.
+  if not user_text and llm_request.contents:
+    for content in reversed(llm_request.contents):
+      if content.role == "user" and content.parts:
+        user_text = content.parts[0].text or ""
+        break
+
+  return LlmResponse(
+      content=types.Content(
+          role="model",
+          parts=[types.Part(text=f"ECHO: {user_text}")],
+      ),
+  )
+
+
+root_agent = Agent(
+    model="gemini-2.5-flash",
+    name="trigger_echo_agent",
+    instruction="Echo agent for trigger testing.",
+    before_model_callback=before_model_callback,
+)