Verify the author information

Oct 13, 2025 by wbrum.org 74 views

Unknown / Unsupported Author: User Error in Gemini (@langchain/google-genai)

When integrating the Gemini models from Google GenAI using the LangChain.js library, some users may encounter an error that reads "Unknown / unsupported author: user." This error can be frustrating, especially when other models like OpenAI and Anthropic work seamlessly. In this article, we will delve into the possible causes of this error and explore potential solutions to resolve the issue.

LangChain.js is a powerful library for building conversational AI applications. It provides a simple and intuitive API for integrating various language models, including those from Google GenAI. The library is designed to be flexible and adaptable, allowing developers to easily switch between different models and configurations.

The error message "Unknown / unsupported author: user" suggests that the issue lies in the way the author information is being processed. In the context of Gemini models, the author is typically represented as a user ID or a unique identifier. However, it appears that the LangChain.js library is unable to recognize or process this information correctly.

To better understand the issue, let's take a look at the example code provided:

ChatGoogleGenerativeAI({
  ...BASE_LLM_OPTIONS,
  model: model,
  apiKey: key,
});

In this code snippet, we can see that the ChatGoogleGenerativeAI function is being called with the model and apiKey parameters. However, the author parameter is not explicitly specified, which may be contributing to the error.

To troubleshoot the issue, it's essential to gather more information about the system configuration and dependencies. Here are the relevant details:

mac: The operating system being used.
@langchain/openai: The version of the OpenAI integration package, which is >=0.1.0 <0.5.0.
js-yaml: The version of the YAML parser, which is ^4.1.0.
openapi-types: The version of the OpenAPI types library, which is ^12.1.3.
yaml: The version of the YAML library, which is ^2.2.1.
@langchain/textsplitters: The version of the text splitter library, which is >=0.0.0 <0.2.0.
jsonpointer: The version of the JSON pointer library, which is ^5.0.1.
p-retry: The version of the retry library, which is 4.
zod-to-json-schema: The version of the JSON schema library, which is ^3.22.3.
js-tiktoken: The version of the TikToken library, which is ^1.0.12.
langsmith: The version of the LangSmith library, which is >=0.2.8 <0.4.0.
uuid: The version of the UUID library, which is ^10.0.0.
zod: The version of the Zod library, which is ^3.22.4.

Based on the analysis, here are some potential solutions to resolve the "Unknown / unsupported author: user" error:

Verify the author information: Ensure that the author information is being passed correctly to the ChatGoogleGenerativeAI function. Check the documentation for the correct format and syntax.
Update the LangChain.js library: Make sure that the LangChain.js library is up-to-date. If the issue persists after updating, try rolling back to a previous version to see if the error is specific to the latest version.
Check the Gemini model configuration: Verify that the Gemini model is configured correctly. Check the documentation for the correct settings and parameters.
Use a different author format: If the author information is being passed as a string, try using a different format, such as an object or an array.
Disable author processing: If the author information is not essential for the application, try disabling author processing altogether.

The "Unknown / unsupported author: user" error in Gemini models using LangChain.js can be frustrating, but it's often a solvable issue. By analyzing the error message, example code, and system information, we can identify potential causes and explore solutions to resolve the issue. Remember to verify the author information, update the LangChain.js library, check the Gemini model configuration, use a different author format, or disable author processing altogether.
Unknown / Unsupported Author: User Error in Gemini (@langchain/google-genai) - Q&A

In our previous article, we explored the "Unknown / unsupported author: user" error in Gemini models using LangChain.js. We analyzed the error message, example code, and system information to identify potential causes and explore solutions to resolve the issue. In this Q&A article, we will answer some frequently asked questions related to this error.

A: The cause of the error is likely due to the way the author information is being processed by the LangChain.js library. The library may not be able to recognize or process the author information correctly, leading to the error.

A: To verify the author information, you can check the documentation for the correct format and syntax. Ensure that the author information is being passed correctly to the ChatGoogleGenerativeAI function. You can also try using a different format, such as an object or an array, to see if the error persists.

A: The potential solutions to resolve the error include:

Verifying the author information
Updating the LangChain.js library
Checking the Gemini model configuration
Using a different author format
Disabling author processing altogether

A: To update the LangChain.js library, you can use the following command:

npm install langchain@latest

Alternatively, you can use the following command to update the library to a specific version:

npm install langchain@<version>

Replace <version> with the desired version number.

A: The system requirements for the LangChain.js library include:

Node.js 14 or later
npm 6 or later
A compatible operating system (Windows, macOS, or Linux)

A: Yes, you can use the LangChain.js library with other language models, including those from OpenAI and Anthropic. However, you may need to modify the code to accommodate the specific requirements of each model.

A: To troubleshoot the error, you can try the following steps:

Check the error message for any clues or hints
Verify the author information and ensure that it is being passed correctly
Update the LangChain.js library to the latest version
Check the Gemini model configuration and ensure that it is correct
Use a different author format or disable author processing altogether

The "Unknown / unsupported author: user" error in Gemini models using LangChain.js can be frustrating, but it's often a solvable issue. By following the potential solutions and troubleshooting steps outlined in this Q&A article, you can resolve the error and get your application up and running. Remember to verify the author information, update the LangChain.js library, check the Gemini model configuration, use a different author format, or disable author processing altogether.