Jupyter Notebooks.
In your pocket.
Callisto is a full Python IDE for Android. Edit and run .ipynb notebooks and .py scripts entirely on your device — no cloud, no account, no internet required.
A real Python IDE — built for touch.
Callisto isn't a code playground. It's a complete editor and runtime, designed from scratch for Android.
100% on-device
CPython 3.10 runs locally via Chaquopy. No servers, no accounts, no telemetry on your code. Works offline on a plane or a train.
Full notebook support
Open, edit, and save real .ipynb v4 files. Insert, duplicate, reorder cells. Run cell, run below, run all. Cooperative interrupt when a run hangs.
Smart editor
CodeMirror 6 with Python syntax highlighting and Jedi auto-completion against the live namespace — df. resolves to actual DataFrame methods.
Scripts & REPL
A .py editor and a Python console live side-by-side with your notebook. Variables flow both ways. Input history persists across sessions.
Markdown & LaTeX
Markdown cells render with KaTeX. Cross-cell \newcommand definitions work. Matplotlib and seaborn figures display inline.
Workspaces & export
Per-file workspace folders. Sibling data/ directory for CSVs. Export single files or a ZIP bundle. "Open with…" support for both file types.
The full scientific stack — pre-installed.
Callisto ships with the libraries you actually use. No pip install, no broken wheels, no waiting for a manylinux build that doesn't exist on ARM.
Free tier includes the core data-science stack. The one-time Lifetime Unlock adds extended packages and premium features — no subscription, ever.
Privacy by design.
No account. No code uploads. Crash diagnostics are anonymous and contain no file contents. Usage analytics are opt-in and off by default. The internet permission exists only so requests works for code you write.