vllm/docs/deployment/frameworks/streamlit.md

# Streamlit

[Streamlit](https://github.com/streamlit/streamlit) lets you transform Python scripts into interactive web apps in minutes, instead of weeks. Build dashboards, generate reports, or create chat apps.

It can be quickly integrated with vLLM as a backend API server, enabling powerful LLM inference via API calls.

## Prerequisites

Set up the vLLM environment by installing all required packages:

```bash
pip install vllm streamlit openai
```

## Deploy

1. Start the vLLM server with a supported chat completion model, e.g.

    ```bash
    vllm serve Qwen/Qwen1.5-0.5B-Chat
    ```

1. Use the script: <gh-file:examples/online_serving/streamlit_openai_chatbot_webserver.py>

1. Start the streamlit web UI and start to chat:

    ```bash
    streamlit run streamlit_openai_chatbot_webserver.py

    # or specify the VLLM_API_BASE or VLLM_API_KEY
    VLLM_API_BASE="http://vllm-server-host:vllm-server-port/v1" \
        streamlit run streamlit_openai_chatbot_webserver.py

    # start with debug mode to view more details
    streamlit run streamlit_openai_chatbot_webserver.py --logger.level=debug
    ```

    ![Chat with vLLM assistant in Streamlit](../../assets/deployment/streamlit-chat.png)