chatlas

Your friendly guide to building LLM chat apps in Python with less effort and more clarity.

Install

Install the latest stable release from PyPI:

pip install -U chatlas

Or, install the latest development version from GitHub:

pip install -U git+https://github.com/posit-dev/chatlas

Quick start

Get started in 3 simple steps:

Choose a model provider, such as ChatOpenAI or ChatAnthropic.
Visit the provider's reference page to get setup with necessary credentials.
Create the relevant Chat client and start chatting!

from chatlas import ChatOpenAI

# Optional (but recommended) model and system_prompt
chat = ChatOpenAI(
    model="gpt-4.1-mini",
    system_prompt="You are a helpful assistant.",
)

# Optional tool registration
def get_current_weather(lat: float, lng: float):
    "Get the current weather for a given location."
    return "sunny"

chat.register_tool(get_current_weather)

# Send user prompt to the model for a response.
chat.chat("How's the weather in San Francisco?")