Marimo – an open-source reactive notebook for Python

In plain words

Marimo is an open-source reactive notebook for Python that addresses common problems with traditional notebooks. Notebooks are stored as Python files, making them git-friendly and reproducible with no hidden state. Marimo automatically runs dependent cells when variables change and removes variables when cells are deleted. The notebooks can be executed as Python scripts or deployed as web apps. The reactive runtime uses static analysis for performance and allows users to disable auto-run on specific cells to avoid expensive computations.

written from the facts on this page · September 2026

From the sources

A reactive notebook for Python — run reproducible experiments, query with SQL, execute as a script, deploy as an app, and version with git. Stored as pure Python. All in a modern, AI-native editor. - marimo-team/marimo

In the maker’s words, at launch

Hi HN! We’re excited to share marimo, an open-source reactive notebook for Python [1]. marimo aims to solve well-known problems with traditional notebooks [2]: marimo notebooks are reproducible (no hidden state), git-friendly (stored as Python files), executable as Python scripts, and deployable as web apps. GitHub…

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  Marimo – open-source reactive Python notebook – running in WASM2024 · marimo.app · ▲102

  Hi HN! Last month, we shared marimo [1][2], an open-source reactive notebook for Python. For those who missed it, marimo notebooks are reproducible, stored as Python files, executable as Python scripts, and deployable as web apps. It’s now possible to run marimo notebooks entirely in the browser via WebAssembly (WASM). - A marimo tutorial as a WASM notebook: https://marimo.app/l/c7h6pz - Training a neural network with Karpathy’s micrograd: https://marimo.app/l/xpd4te - Visualizing attractors, as a read-only app:…

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  marimo2024 · marimo.io · ▲252

  The next-generation Python notebook

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  Marimo pair – Reactive Python notebooks as environments for agentsApr 2026 · github.com · ▲140

  Hi HN! We're excited to share marimo pair [1] [2], a toolkit that drops AI agents into a running marimo notebook [3] session. This lets agents use marimo as working memory and a reactive Python runtime, while also making it easy for humans and agents to collaborate on computational research and data work. GitHub repo: https://github.com/marimo-team/marimo-pair Demo: https://www.youtube.com/watch?v=6uaqtchDnoc marimo pair is implemented as an agent skill. Connect your agent of choice to a running notebook with: /marimo-pair pair with me on…

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