Solara

Solara is an open-source framework created by Maarten Breddels and developed by Widgetti, a small Netherlands-based company focused on tools for the Jupyter ecosystem. It lets developers build web applications and dashboards entirely in Python using a React-like component API. Apps run both inside Jupyter environments and as standalone web apps served with FastAPI/Starlette.

What It Is

Solara is a Python web application framework built on Reacton, a pure Python implementation of React, which produces ipywidget-based applications. Developers declare reactive variables and components, and the UI re-renders automatically when values change. The project states this component model is intended to keep code organization, reusability and state manageable as applications grow.

Workflow and Outputs

Install with pip, write a script or notebook cell defining components, and run it with solara run sol.py to start a local server, or render the component directly in a Jupyter notebook. The Solara server is built on Starlette/FastAPI and runs standalone for production use. Because it builds on ipywidgets, apps can run on JupyterLab, Jupyter Notebook, Voilà, Google Colab, Databricks, JetBrains Datalore and others.

Developer Experience

The documentation highlights hot code reloading, type hints and type safety, a built-in component library, and testability with and without a browser, including CI/CD automation. New front-end components can be created with frameworks such as React or Vue, and Python libraries can be called directly without building REST endpoints.