Continuing my journey with Javelit, after creating a frontend for “Nano Banana” to generate images and a chat interface for a LangChain4j-based Gemini chat model, I decided to see how I could integrate an ADK agent with a Javelit frontend.

The Javelit interface for an ADK search agent

The key ingredients of this interface:

• a title (with some emojis 😃)
• a container that displays the agent’s answer
• a text input field to enter the search query

The ADK agent

For the purpose of this article, I built a simple search agent, with a couple of search tools:

Yesterday, I uncovered the Javelit project in this article where I built a small frontend to create and edit images with Google’s Nano Banana image model.

Javelit is an open source project inspired by Streamlit from the Python ecosystem to enable rapid prototyping and deployment of applications in Java.

Today, I want to show you another example of Javelit. This time, I’m creating a chat interface using LangChain4j with the Gemini chat model.

What we want to build

Have you ever heard of Javelit? It’s like Streamlit in the Python ecosystem, but for the Java developer! I was lucky that the project creator reached out and introduced me to this cool little tool!

Javelit is a tool to quickly build interactive app frontends in Java, particularly for data apps, but it’s not limited to them. It helps you quickly develop rapid prototypes, with a live-reload loop, so that you can quickly experiment and update the app instantly.