GoogleCloudPlatform · allen-stephen · Nov 13, 2025 · Nov 13, 2025 · Nov 14, 2025 · Nov 14, 2025
diff --git a/.cloudbuild/terraform/build_triggers.tf b/.cloudbuild/terraform/build_triggers.tf
@@ -67,16 +67,12 @@ locals {
       value = "adk_base,cloud_run"
     },
     {
-      name  = "langgraph_base_react-agent_engine"
-      value = "langgraph_base_react,agent_engine"
+      name  = "langgraph_base-agent_engine"
+      value = "langgraph_base,agent_engine"
     },
     {
-      name  = "langgraph_base_react-cloud_run"
-      value = "langgraph_base_react,cloud_run,-dir,tag"
-    },
-    {
-      name  = "crewai_coding_crew-agent_engine"
-      value = "crewai_coding_crew,agent_engine"
+      name  = "langgraph_base-cloud_run"
+      value = "langgraph_base,cloud_run,-dir,tag"
     },
     {
       name  = "crewai_coding_crew-cloud_run"
@@ -157,8 +153,8 @@ agent_testing_included_files = { for combo in local.agent_testing_combinations :
       value = "adk_base,cloud_run,-dir,tag"
     },
     {
-      name = "langgraph_base_react-agent_engine"
-      value = "langgraph_base_react,agent_engine"
+      name = "langgraph_base-agent_engine"
+      value = "langgraph_base,agent_engine"
     },
     {
       name = "agentic_rag-agent_engine-vertex_ai_search"

diff --git a/GEMINI.md b/GEMINI.md
@@ -191,7 +191,7 @@ SKIP_MYPY=1 _TEST_AGENT_COMBINATION="crewai_coding_crew,cloud_run" make lint-tem
 
 # Testing examples
 _TEST_AGENT_COMBINATION="adk_base,cloud_run,--session-type,in_memory" make test-templated-agents
-_TEST_AGENT_COMBINATION="langgraph_base_react,agent_engine" make test-templated-agents
+_TEST_AGENT_COMBINATION="langgraph_base,agent_engine" make test-templated-agents
 ```
 
 ### Critical Whitespace Control Patterns
@@ -219,7 +219,7 @@ from opentelemetry.sdk.trace import TracerProvider, export
 from vertexai import agent_engines
 {% endif %}
 
-{%- if cookiecutter.is_adk_a2a %}
+{%- if cookiecutter.is_a2a %}
 from {{cookiecutter.agent_directory}}.agent import app as adk_app
 
 {% endif %}
@@ -337,7 +337,7 @@ find agent_starter_pack -name "fast_api_app.py" -type f
    - End-of-file newline issues
 
 2. **`fast_api_app.py`** (deployment_targets/cloud_run/)
-   - Conditional imports (session_type, is_adk_a2a)
+   - Conditional imports (session_type, is_a2a)
    - Long import lines
    - Complex nested conditionals
 
@@ -365,7 +365,7 @@ SKIP_MYPY=1 _TEST_AGENT_COMBINATION="adk_base,agent_engine" make lint-templated-
 # For agent_engine changes:
 SKIP_MYPY=1 _TEST_AGENT_COMBINATION="adk_base,agent_engine" make lint-templated-agents
 SKIP_MYPY=1 _TEST_AGENT_COMBINATION="adk_live,agent_engine" make lint-templated-agents
-SKIP_MYPY=1 _TEST_AGENT_COMBINATION="langgraph_base_react,agent_engine" make lint-templated-agents
+SKIP_MYPY=1 _TEST_AGENT_COMBINATION="langgraph_base,agent_engine" make lint-templated-agents
 ```
 
 ### Quick Reference: Whitespace Control Cheat Sheet

diff --git a/README.md b/README.md
@@ -70,7 +70,7 @@ See [Installation Guide](https://googlecloudplatform.github.io/agent-starter-pac
 | `adk_base`      | A base ReAct agent implemented using Google's [Agent Development Kit](https://github.com/google/adk-python) |
 | `adk_a2a_base`  | An ADK agent with [Agent2Agent (A2A) Protocol](https://a2a-protocol.org/) support for distributed agent communication and interoperability |
 | `agentic_rag` | A RAG agent for document retrieval and Q&A. Supporting [Vertex AI Search](https://cloud.google.com/generative-ai-app-builder/docs/enterprise-search-introduction) and [Vector Search](https://cloud.google.com/vertex-ai/docs/vector-search/overview).       |
-| `langgraph_base_react`      | An agent implementing a base ReAct agent using LangGraph |
+| `langgraph_base`      | A base ReAct agent implemented using LangChain's [LangGraph](https://github.com/langchain-ai/langgraph) |
 | `crewai_coding_crew`       | A multi-agent system implemented with CrewAI created to support coding activities       |
 | `adk_live`       | A real-time multimodal RAG agent powered by Gemini, supporting audio/video/text chat     |
 

diff --git a/agent_starter_pack/agents/crewai_coding_crew/.template/templateconfig.yaml b/agent_starter_pack/agents/crewai_coding_crew/.template/templateconfig.yaml
@@ -15,7 +15,7 @@
 description: "A multi-agent system implemented with CrewAI created to support coding activities"
 settings:
   requires_data_ingestion: false
-  deployment_targets: ["agent_engine", "cloud_run"]
+  deployment_targets: ["cloud_run"]
   extra_dependencies: [
     "langchain-google-vertexai>=2.0.7",
     "langchain~=0.3.14",

diff --git a/..._base_react/.template/templateconfig.yaml → ...ggraph_base/.template/templateconfig.yaml b/..._base_react/.template/templateconfig.yaml → ...ggraph_base/.template/templateconfig.yaml
@@ -12,16 +12,19 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-description: "An agent implementing a base ReAct agent using LangGraph"
+description: "A base ReAct agent implemented using LangGraph with Agent2Agent (A2A) Protocol support"
 settings:
   requires_data_ingestion: false
   deployment_targets: ["agent_engine", "cloud_run"]
   extra_dependencies: [
-    "langchain-google-vertexai>=2.0.7",
-    "langchain~=0.3.14",
-    "langgraph~=0.6.2",
-    "langchain-community~=0.3.17",
-    "langchain-openai~=0.3.5",
+    "langchain-google-vertexai>=3.0.3",
+    "langchain~=1.0.5",
+    "langgraph~=1.0.3",
+    "langchain-community~=0.4.1",
+    "langchain-openai~=1.0.2",
+    "a2a-sdk[http-server]~=0.3.9",
+    "nest-asyncio>=1.6.0,<2.0.0",
   ]
-  frontend_type: "streamlit"
-example_question: "What's the weather in San Francisco?"
+  tags: ["langgraph", "a2a"]
+  frontend_type: "inspector"
+example_question: "What's the weather in San Francisco?"
diff --git a/agent_starter_pack/agents/langgraph_base/README.md b/agent_starter_pack/agents/langgraph_base/README.md
@@ -0,0 +1,25 @@
+# LangGraph Base ReAct Agent with A2A Protocol
+
+<p align="center">
+  <img src="https://langchain-ai.github.io/langgraph/static/wordmark_dark.svg" width="50%" alt="LangGraph Logo" style="margin-right: 40px; vertical-align: middle;">
+  <img src="https://github.com/a2aproject/A2A/blob/main/docs/assets/a2a-logo-white.svg?raw=true" width="40%" alt="A2A Logo" style="vertical-align: middle;">
+</p>
+
+A base ReAct agent built using **[LangGraph](https://docs.langchain.com/oss/python/langgraph/overview)** with **[Agent2Agent (A2A) Protocol](https://a2a-protocol.org/)** support. This example demonstrates how to build a LangGraph-based agent with distributed agent communication capabilities through the A2A protocol for interoperability with agents across different frameworks and languages.
+
+## Key Features
+
+- **Simple Architecture**: Shows the basic building blocks of a LangGraph agent
+- **A2A Protocol Support**: Enables distributed agent communication and interoperability
+- **Streaming Support**: Includes streaming response capability using Vertex AI
+- **Sample Tool Integration**: Includes a basic search tool to demonstrate tool usage
+
+## Validating Your A2A Implementation
+
+When deploying to **Cloud Run**, this template includes the **[A2A Protocol Inspector](https://github.com/a2aproject/a2a-inspector)** for validating your agent's A2A implementation.
+
+```bash
+make inspector
+```
+
+For detailed setup instructions including local and remote testing workflows, refer to the `README.md` in your generated project.
diff --git a/agent_starter_pack/agents/langgraph_base/app/__init__.py b/agent_starter_pack/agents/langgraph_base/app/__init__.py
@@ -0,0 +1,17 @@
+# 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 .agent import root_agent
+
+__all__ = ["root_agent"]
diff --git a/.../agents/langgraph_base_react/app/agent.py → ...r_pack/agents/langgraph_base/app/agent.py b/.../agents/langgraph_base_react/app/agent.py → ...r_pack/agents/langgraph_base/app/agent.py
@@ -12,9 +12,9 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-# mypy: disable-error-code="union-attr"
+from langchain.agents import create_agent
 from langchain_google_vertexai import ChatVertexAI
-from langgraph.prebuilt import create_react_agent
+from langgraph.graph.state import CompiledStateGraph
 
 LOCATION = "global"
 LLM = "gemini-2.5-flash"
@@ -29,6 +29,6 @@ def get_weather(query: str) -> str:
     return "It's 90 degrees and sunny."
 
 
-agent = create_react_agent(
-    model=llm, tools=[get_weather], prompt="You are a helpful assistant"
+root_agent: CompiledStateGraph = create_agent(
+    model=llm, tools=[get_weather], system_prompt="You are a helpful assistant"
 )
diff --git a/agent_starter_pack/agents/langgraph_base/app/converters/__init__.py b/agent_starter_pack/agents/langgraph_base/app/converters/__init__.py
@@ -0,0 +1,25 @@
+# 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.
+
+"""Converters for A2A and LangChain types."""
+
+from .part_converter import (
+    convert_a2a_parts_to_langchain_content,
+    convert_langchain_content_to_a2a_parts,
+)
+
+__all__ = [
+    "convert_a2a_parts_to_langchain_content",
+    "convert_langchain_content_to_a2a_parts",
+]
diff --git a/agent_starter_pack/agents/langgraph_base/app/converters/part_converter.py b/agent_starter_pack/agents/langgraph_base/app/converters/part_converter.py
@@ -0,0 +1,164 @@
+# 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.
+
+"""Converters between A2A Parts and LangChain message content."""
+
+from __future__ import annotations
+
+import logging
+from typing import Any
+
+from a2a.types import FilePart, FileWithBytes, FileWithUri, Part, TextPart
+
+logger = logging.getLogger(__name__)
+
+
+LangChainContent = str | list[str | dict[str, Any]]
+LangChainContentDict = dict[str, Any]
+
+
+def convert_a2a_part_to_langchain_content(part: Part) -> LangChainContentDict | str:
+    """Convert an A2A Part to LangChain message content format."""
+
+    root = part.root
+
+    if isinstance(root, TextPart):
+        return {"type": "text", "text": root.text}
+
+    elif isinstance(root, FilePart):
+        file_data = root.file
+        mime_type = file_data.mime_type if hasattr(file_data, "mime_type") else None
+
+        # Determine media type from mime_type
+        media_type = "image"  # default
+        if mime_type:
+            if mime_type.startswith("audio/"):
+                media_type = "audio"
+            elif mime_type.startswith("video/"):
+                media_type = "video"
+
+        if isinstance(file_data, FileWithUri):
+            return {"type": media_type, "url": file_data.uri}
+        else:
+            # Base64 data should already be encoded
+            return {
+                "type": media_type,
+                "base64": file_data.bytes,
+                "mime_type": mime_type or "application/octet-stream",
+            }
+
+    else:
+        import json
+
+        data_str = json.dumps(root.data, indent=2)
+        return {"type": "text", "text": f"[Structured Data]\n{data_str}"}
+
+
+def convert_langchain_content_to_a2a_part(content: Any) -> Part:
+    """Convert LangChain message content to an A2A Part."""
+
+    if isinstance(content, str):
+        return Part(root=TextPart(text=content))
+
+    if isinstance(content, dict):
+        content_type = content.get("type")
+
+        if content_type == "text":
+            text = content.get("text", "")
+            return Part(root=TextPart(text=text))
+
+        elif content_type in ("image", "audio", "video"):
+            # Handle URL-based media
+            if "url" in content:
+                url = content["url"]
+                if url.startswith("data:"):
+                    # Parse data URI format: data:mime_type;base64,data
+                    try:
+                        header, base64_data = url.split(",", 1)
+                        mime_type = header.split(";")[0].replace("data:", "")
+                        return Part(
+                            root=FilePart(
+                                file=FileWithBytes(
+                                    bytes=base64_data, mime_type=mime_type or None
+                                )
+                            )
+                        )
+                    except Exception as e:
+                        logger.warning(f"Failed to parse data URI: {e}")
+                        return Part(root=FilePart(file=FileWithUri(uri=url)))
+                else:
+                    return Part(root=FilePart(file=FileWithUri(uri=url)))
+
+            # Handle base64-encoded media
+            elif "base64" in content:
+                mime_type = content.get("mime_type")
+                return Part(
+                    root=FilePart(
+                        file=FileWithBytes(bytes=content["base64"], mime_type=mime_type)
+                    )
+                )
+
+            # Handle file_id-based media
+            elif "file_id" in content:
+                return Part(
+                    root=FilePart(file=FileWithUri(uri=f"file://{content['file_id']}"))
+                )
+
+        else:
+            import json
+
+            text = json.dumps(content)
+            logger.warning(f"Unknown content type '{content_type}', converting to text")
+            return Part(root=TextPart(text=text))
+
+    logger.warning(f"Unknown content type: {type(content)}, converting to text")
+    return Part(root=TextPart(text=str(content)))
+
+
+def convert_a2a_parts_to_langchain_content(parts: list[Part]) -> LangChainContent:
+    """Convert a list of A2A Parts to LangChain message content."""
+
+    if not parts:
+        return ""
+
+    converted: list[str | dict[str, Any]] = []
+    for part in parts:
+        result = convert_a2a_part_to_langchain_content(part)
+        converted.append(result)
+
+    if len(converted) == 1 and isinstance(converted[0], str):
+        return converted[0]
+
+    if (
+        len(converted) == 1
+        and isinstance(converted[0], dict)
+        and converted[0].get("type") == "text"
+    ):
+        text_value = converted[0].get("text")
+        if isinstance(text_value, str):
+            return text_value
+
+    return converted
+
+
+def convert_langchain_content_to_a2a_parts(content: LangChainContent) -> list[Part]:
+    """Convert LangChain message content to a list of A2A Parts."""
+
+    if isinstance(content, str):
+        return [Part(root=TextPart(text=content))]
+
+    result: list[Part] = []
+    for item in content:
+        result.append(convert_langchain_content_to_a2a_part(item))
+    return result
diff --git a/agent_starter_pack/agents/langgraph_base/app/executor/__init__.py b/agent_starter_pack/agents/langgraph_base/app/executor/__init__.py
@@ -0,0 +1,13 @@
+# 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.