LangChain google-common

This package contains common resources to access Google AI/ML models and other Google services in an auth-independent way.

AI/ML models are supported using the same interface no matter if you are using the Google AI Studio-based version of the model or the Google Cloud Vertex AI version of the model.

Installation

This is not a stand-alone package since it does not contain code to do authorization.

Instead, you should install one of the following packages:

• @langchain/google-gauth
• @langchain/google-webauth

See those packages for details about installation.

This package does not depend on any Google library. Instead, it relies on REST calls to Google endpoints. This is deliberate to reduce (sometimes conflicting) dependencies and make it usable on platforms that do not include file storage.

Google services supported

• Gemini model through LLM and Chat classes (both through Google AI Studio and Google Cloud Vertex AI). Including:
  • Function/Tool support

Known Limitations

Tool/Function Schema Limitations

When using tools or functions with Gemini models, the following Zod schema features are not supported:

• Discriminated Unions (z.discriminatedUnion()) - Use flat objects with optional fields instead
• Union Types (z.union()) - Use separate optional fields
• Positive Refinement (z.number().positive()) - Automatically converted to z.number().min(0.01)

For detailed examples and workarounds, see the Tool Schema Limitations section in the @langchain/google-vertexai or @langchain/google-genai package documentation.

TODO

Tasks and services still to be implemented:

• PaLM Vertex AI support and backwards compatibility
• PaLM MakerSuite support and backwards compatibility
• Semantic Retrieval / AQA model
• PaLM embeddings
• Gemini embeddings
• Multimodal embeddings
• Vertex AI Search
• Vertex AI Model Garden
  • Online prediction endpoints
    • Gemma
  • Google managed models
    • Claude
• AI Studio Tuned Models
• MakerSuite / Google Drive Hub
• Google Cloud Vector Store