Hi everyone,
I’m looking for some guidance regarding the recent deprecation of parts of the google-cloud-aiplatform SDK.
I’ve built an agent using the LangchainAgent class from the vertexai.preview.reasoning_engines package (also referred to as vertex.agent_engines). In my implementation, I rely on Tool and grounding from vertexai.generative_models, which have officially entered deprecation as of June 24.
As part of reviewing my code for migration to the new Google GenAI SDK (google-genai), I explored using Tool with Retrieval and VertexAISearch. However, this approach is currently not compatible with the LangchainAgent class — it throws an error indicating Unsupported tool call type.
My question is: Is there currently any official way to use LangchainAgent with the new google-genai SDK? Or for now, is the only viable path to continue using the deprecated vertexai.generative_models modules until support is updated?
I chose this architecture because, in addition to producing excellent responses for my use case, the LangchainAgent also supports native integration with Firestore, which is crucial for managing chat history.
I’d really appreciate any guidance or recommendations on how to proceed in this situation. 
Hi @angelica_viana,
Welcome to the Google Cloud Community!
Yes, you are correct, According to this documentation:
The Generative AI module in the Vertex AI SDK is deprecated and will no longer be available after June 24, 2026. The Google Gen AI SDK contains all the capabilities of the Vertex AI SDK, and supports many additional capabilities.
This includes vertexai.generative_models, which you are currently using and is now in the deprecation phase. SDK releases after June 24, 2026, will not include this module, and it is advised to use the equivalent namespace from the Google Gen AI SDK.
For your use case, currently there is no official documentation on Google Cloud regarding the LangchainAgent with the Google Gen AI SDK, the Vertex AI Agent Engine formerly known as LangChain on Vertex AI is supported under Vertex AI SDK for Python. Migration is a common challenge specially with some integration gaps, temporary solution is to continue using the vertexai.generative_models while continuous development on Gen AI SDK integration gaps, though kindly note that it may stop working at any time due to obsolete dependencies or other factors.
In addition, Keep an eye on the Vertex AI release notes for updates on Vertex AI SDK.
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Is there any updated documentation regarding this topic? I’d like to know if it’s still possible to maintain the LangchainAgent even with this deprecation?