solara

library1.57.4pypypi✓ verified 90d ago

Solara is an open-source Python library designed to simplify building reactive web applications using ipywidgets and a React-like API. It allows developers to create sophisticated data apps that run seamlessly both within Jupyter Notebooks and as standalone web applications, leveraging frameworks like FastAPI or Starlette. Solara is currently on version 1.57.3 and maintains an active release cadence with frequent updates and bug fixes.

web-framework data

pip install solara

package ↗homepage ↗docs ↗

INSTALL

IMPORT

SIG · SOLARA

solara

web-frameworkpythonv1.57.4

Install

16.2s avg

Import

4280ms

Disk

253MB

Pass rate

10/ 10

Env Coverage10 / 10

glibc

3.9–3.13

musl

3.9–3.13

Install & Compatibility

Where this runs

tested against v1.57.4 · pip install

no network on importno background threads

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

py 3.10–3.920 runs

installs and imports cleanly · install 0.0s · import 4.375s · 264.5MB

glibc

py 3.10–3.920 runs

installs and imports cleanly · install 16.2s · import 4.185s · 244MB

253MB installed

● package 253MB

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

solara

✓ import solara

Primary import for all Solara components and functions.

This quickstart demonstrates a simple interactive Solara application with reactive state. It includes a text input and a slider, with dynamic feedback based on word count. Save this as a `.py` file (e.g., `app.py`) and run it using `solara run app.py` from your terminal. For Jupyter Notebooks, append `Page()` to display the component.

import solara sentence = solara.reactive("Solara makes our team more productive.") word_limit = solara.reactive(10) @solara.component def Page(): word_count = len(sentence.value.split()) solara.SliderInt("Word limit", value=word_limit, min=2, max=20) solara.InputText(label="Your sentence", value=sentence, continuous_update=True) if word_count >= int(word_limit.value): solara.Error(f"With {word_count} words, you passed the word limit of {word_limit.value}.") elif word_count >= int(0.8 * word_limit.value): solara.Warning(f"With {word_count} words, you are close to the word limit of {word_limit.value}.") else: solara.Success("Great short writing!") # To run this in a .py file from the command line: `solara run your_app.py` # To run this in a Jupyter Notebook cell, add the following line at the end: # Page()

solara --version

Debug

Known issues

breakingSolara dropped support for Python 3.7. Applications running on Python 3.7 will not be compatible with Solara versions 1.56.0 and higher.

fix

Upgrade your Python environment to 3.8 or newer.

affects: >=1.56.0

gotchaWhen defining state, `solara.reactive()` creates global, per-session state, while `solara.use_state()` creates component-specific local state. Using `solara.reactive()` for local component state can lead to unexpected behavior across multiple instances of the same component.

fix

Use `solara.reactive()` for application-wide or session-wide state. Use `solara.use_state()` within components for local, isolated state.

affects: All

gotchaWhen running Solara applications directly in a Jupyter Notebook cell, you must explicitly call the main `@solara.component` (typically `Page`) at the end of the cell (e.g., `Page()`) for it to render. This is not necessary when running with `solara run`.

fix

Add `Page()` (or the name of your main component function) as the last line in the Jupyter Notebook cell containing your Solara app code.

affects: All

breakingA security fix (CVE-2026-24008) for a path traversal vulnerability in `path_is_child_of` was implemented. Older versions may be vulnerable.

fix

Upgrade Solara to version 1.57.2 or higher to address the path traversal vulnerability.

affects: <1.57.2

gotchaSolara server in Docker environments may fail to start if the `$HOME` environment variable is not set or points to a non-writable directory, even if a bug fix for this was implemented in v1.50.1.

fix

Ensure the `$HOME` environment variable is set to a writable directory within your Docker container or development environment.

affects: All

Errors

Common errors & fixes

ModuleNotFoundError: No module named 'solara'

The Solara library has not been installed in the current Python environment.

fix

Run `pip install solara` to install the library.

RuntimeError in BaseSettings iteration

This error can occur in Solara versions prior to 1.55.0 when running with Python 3.14 due to compatibility issues with `BaseSettings`.

fix

Upgrade Solara to version 1.55.0 or higher. `pip install --upgrade solara`

Solara app not rendering in Jupyter Notebook

The main component function (e.g., `Page`) was not explicitly called at the end of the Jupyter cell.

fix

Add `Page()` at the end of the Jupyter Notebook cell to render the Solara application.

Upgrade

Version history

1.57.4latest on PyPI · released May 14, 2026

Audit

Dependencies

ipywidgetsrequiredCore UI component foundation.

solara-serverrequiredRequired for running standalone Solara applications outside Jupyter.

FastAPIoptionalCommon backend for standalone Solara applications.

StarletteoptionalAlternative backend for standalone Solara applications.

Agent activity

48 hits · last 30 days

node

OpenAI (training)

Resources

packagehttps://pypi.org/project/solara/ ↗

homepagehttps://solara.dev ↗

docshttps://solara.dev ↗