Java AI chatbot that uses your documents as context

This app demonstrates how you can create a custom AI chatbot that can use your own documents to answer questions using RAG (retrieval augmented generation). The chatbot uses LangChain4j and the OpenAI API to generate responses and Vaadin to create the user interface.

Important

Before you can use the application you need to:

Configure the documentation location
Configure either OpenAi or a local LLM

🛠️ Configuration

Configuring documentation location

Update the docs.location property in application.properties to point to a folder with relevant documents. LangChain4j uses Apache Tika internally when processing the files, so most file types work.

Using Open AI

OpenAI gives you better quality answers but requires you to send data to a 3rd party.

To use OpenAI, get an API key and configure it in application.properties. Optionally, you can also configure the model in the properties.

Using a local LLM

Using a local model allows you to keep your data on your local computer, but the quality of answers will not be as good as with OpenAI.

Install Ollama and the llama3 model. Comment out the OpenAI section of application.properties and uncomment the Ollama section.

Optional: Embedding store (Vector DB)

By default, the application uses an in-memory embedding store. This is fine for demos and small amounts of data. If you need to store more documents, consider using any of the embedding stores that LangChain4j supports.

▶️ Running the application

The project is a standard Maven project. To run it from the command line, type mvnw (Windows), or ./mvnw (Mac & Linux), then open http://localhost:8080 in your browser.

You can also import the project to your IDE of choice as you would with any Maven project. Read more on how to import Vaadin projects to different IDEs (Eclipse, IntelliJ IDEA, NetBeans, and VS Code).