From 8f353d3a3e1f8b63e86f51ce4fd4abc651dad646 Mon Sep 17 00:00:00 2001 From: Mend Renovate Date: Tue, 1 Sep 2026 22:04:39 +0000 Subject: [PATCH 1/3] chore(deps): update dependency google-cloud-aiplatform to v2 --- samples/requirements.txt | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/samples/requirements.txt b/samples/requirements.txt index 0cded642..8c775fb6 100644 --- a/samples/requirements.txt +++ b/samples/requirements.txt @@ -1,4 +1,4 @@ -google-cloud-aiplatform[reasoningengine,langchain]==1.134.0 +google-cloud-aiplatform[reasoningengine,langchain]==2.1.0 google-cloud-resource-manager==1.16.0 langchain-community==0.3.29 langchain-google-cloud-sql-pg==0.15.0 From 37fcee10dc2a92c0a4b3e3496adb7069e9c9d716 Mon Sep 17 00:00:00 2001 From: Twisha Bansal Date: Fri, 11 Sep 2026 13:06:50 +0530 Subject: [PATCH 2/3] chore(samples): repoint Vertex samples at langchain-classic for aiplatform v2 aiplatform v2's langchain extra moves langchain from 0.3 to 1.x, which relocates the legacy agent and chain APIs into the separate langchain-classic distribution that the extra now installs. Repoint the two Vertex sample templates at their new locations. Bump samples/langchain_on_vertexai/requirements.txt in lockstep. That file is passed to ReasoningEngine.create() and is what the deployed agent installs, so leaving it on v1 would resolve langchain 0.3 and fail to find langchain_classic at import time. Pin langchain-classic explicitly rather than relying on the extra to supply it. The extra's contents are exactly what shifted here -- v2 also dropped langchain-google-vertexai in favor of langchain-google-genai. --- samples/langchain_on_vertexai/requirements.txt | 3 ++- .../retriever_agent_with_history_template.py | 6 +++--- samples/langchain_on_vertexai/retriever_chain_template.py | 4 ++-- samples/requirements.txt | 1 + 4 files changed, 8 insertions(+), 6 deletions(-) diff --git a/samples/langchain_on_vertexai/requirements.txt b/samples/langchain_on_vertexai/requirements.txt index aa80c386..72fefdae 100644 --- a/samples/langchain_on_vertexai/requirements.txt +++ b/samples/langchain_on_vertexai/requirements.txt @@ -1,5 +1,6 @@ -google-cloud-aiplatform[reasoningengine,langchain]==1.134.0 +google-cloud-aiplatform[reasoningengine,langchain]==2.1.0 google-cloud-resource-manager==1.16.0 +langchain-classic==1.0.8 langchain-community==0.3.31 langchain-google-cloud-sql-pg==0.15.0 langchain-google-vertexai==2.1.2 diff --git a/samples/langchain_on_vertexai/retriever_agent_with_history_template.py b/samples/langchain_on_vertexai/retriever_agent_with_history_template.py index bba06a16..00c4586c 100644 --- a/samples/langchain_on_vertexai/retriever_agent_with_history_template.py +++ b/samples/langchain_on_vertexai/retriever_agent_with_history_template.py @@ -26,9 +26,9 @@ TABLE_NAME, USER, ) -from langchain import hub -from langchain.agents import AgentExecutor, create_react_agent -from langchain.tools.retriever import create_retriever_tool +from langchain_classic import hub +from langchain_classic.agents import AgentExecutor, create_react_agent +from langchain_classic.tools.retriever import create_retriever_tool from langchain_core.runnables.history import RunnableWithMessageHistory from langchain_google_vertexai import ChatVertexAI, VertexAIEmbeddings from vertexai.preview import reasoning_engines # type: ignore diff --git a/samples/langchain_on_vertexai/retriever_chain_template.py b/samples/langchain_on_vertexai/retriever_chain_template.py index 0d322ba8..bfb6dea5 100644 --- a/samples/langchain_on_vertexai/retriever_chain_template.py +++ b/samples/langchain_on_vertexai/retriever_chain_template.py @@ -25,8 +25,8 @@ TABLE_NAME, USER, ) -from langchain.chains.combine_documents import create_stuff_documents_chain -from langchain.chains.retrieval import create_retrieval_chain +from langchain_classic.chains.combine_documents import create_stuff_documents_chain +from langchain_classic.chains.retrieval import create_retrieval_chain from langchain_core.prompts import ChatPromptTemplate from langchain_google_vertexai import VertexAI, VertexAIEmbeddings from vertexai.preview import reasoning_engines # type: ignore diff --git a/samples/requirements.txt b/samples/requirements.txt index 8c775fb6..40545224 100644 --- a/samples/requirements.txt +++ b/samples/requirements.txt @@ -1,5 +1,6 @@ google-cloud-aiplatform[reasoningengine,langchain]==2.1.0 google-cloud-resource-manager==1.16.0 +langchain-classic==1.0.8 langchain-community==0.3.29 langchain-google-cloud-sql-pg==0.15.0 langchain-google-vertexai==2.1.2 From 3831776525a6b643076e0932a0c228c9cff0bd67 Mon Sep 17 00:00:00 2001 From: Twisha Bansal Date: Tue, 15 Sep 2026 14:00:02 +0530 Subject: [PATCH 3/3] chore(samples): bump Vertex samples to gemini-2.5-flash gemini-2.0-flash-001 is retired, so the reasoning-engine integration test fails at query time with a 404 on the publisher model. Verified gemini-2.5-flash resolves in langchain-cloud-sql-testing/us-central1. No token caps in these templates, so 2.5 thinking has no budget to starve. --- .../prebuilt_langchain_agent_template.py | 4 ++-- .../retriever_agent_with_history_template.py | 4 ++-- samples/langchain_on_vertexai/retriever_chain_template.py | 4 ++-- 3 files changed, 6 insertions(+), 6 deletions(-) diff --git a/samples/langchain_on_vertexai/prebuilt_langchain_agent_template.py b/samples/langchain_on_vertexai/prebuilt_langchain_agent_template.py index efd7fb58..5202c5a6 100644 --- a/samples/langchain_on_vertexai/prebuilt_langchain_agent_template.py +++ b/samples/langchain_on_vertexai/prebuilt_langchain_agent_template.py @@ -75,7 +75,7 @@ def similarity_search(query: str) -> list[Document]: # Uncomment to test locally # app = reasoning_engines.LangchainAgent( -# model="gemini-2.0-flash-001", +# model="gemini-2.5-flash", # tools=[similarity_search], # model_kwargs={ # "temperature": 0.1, @@ -92,7 +92,7 @@ def similarity_search(query: str) -> list[Document]: remote_app = reasoning_engines.ReasoningEngine.create( reasoning_engines.LangchainAgent( # type: ignore[arg-type] - model="gemini-2.0-flash-001", + model="gemini-2.5-flash", tools=[similarity_search], # type: ignore[list-item] model_kwargs={ "temperature": 0.1, diff --git a/samples/langchain_on_vertexai/retriever_agent_with_history_template.py b/samples/langchain_on_vertexai/retriever_agent_with_history_template.py index 00c4586c..1179af9e 100644 --- a/samples/langchain_on_vertexai/retriever_agent_with_history_template.py +++ b/samples/langchain_on_vertexai/retriever_agent_with_history_template.py @@ -151,7 +151,7 @@ def query(self, input: str, session_id: str, **kwargs: Any) -> str: # type: ign # Uncomment to test locally # app = PostgresAgent( -# model="gemini-2.0-flash-001", +# model="gemini-2.5-flash", # project=PROJECT_ID, # region=REGION, # instance=INSTANCE, @@ -173,7 +173,7 @@ def query(self, input: str, session_id: str, **kwargs: Any) -> str: # type: ign remote_app = reasoning_engines.ReasoningEngine.create( PostgresAgent( - model="gemini-2.0-flash-001", + model="gemini-2.5-flash", project=PROJECT_ID, region=REGION, instance=INSTANCE, diff --git a/samples/langchain_on_vertexai/retriever_chain_template.py b/samples/langchain_on_vertexai/retriever_chain_template.py index bfb6dea5..8f03c3d6 100644 --- a/samples/langchain_on_vertexai/retriever_chain_template.py +++ b/samples/langchain_on_vertexai/retriever_chain_template.py @@ -123,7 +123,7 @@ def query(self, input: str, **kwargs: Any) -> str: # type: ignore[override] # Uncomment to test locally # app = PostgresRetriever( -# model="gemini-2.0-flash-001", +# model="gemini-2.5-flash", # project=PROJECT_ID, # region=REGION, # instance=INSTANCE, @@ -143,7 +143,7 @@ def query(self, input: str, **kwargs: Any) -> str: # type: ignore[override] remote_app = reasoning_engines.ReasoningEngine.create( PostgresRetriever( - model="gemini-2.0-flash-001", + model="gemini-2.5-flash", project=PROJECT_ID, region=REGION, instance=INSTANCE,