ipynb-local-viewer 0.1.0

A smooth local reader for saved Jupyter notebooks with lazy media output streaming.

ipynb-local-viewer

A smooth, local-first reader for saved Jupyter notebooks.

ipynb-local-viewer turns an .ipynb file into a fast reading surface: markdown headings become an outline, outputs are shown first, code is collapsed behind syntax-highlighted expandable blocks, and large images or videos are loaded through lazy streamed asset URLs instead of being embedded into the main page payload.

It reads saved notebooks only. It does not execute code.

Features

• Markdown-derived outline with smooth section navigation.
• Lazy image and video output loading for media-heavy notebooks.
• Collapsed code cells with Pygments syntax highlighting.
• Safe sanitized HTML output rendering with Bleach.
• Light, dark, and device theme modes.
• Local Flask server with no frontend build step.
• Root-restricted notebook access for safer local browsing.
• Small decoded media cache for faster repeat reads.

Install

python -m pip install ipynb-local-viewer

For local development from a checkout:

python -m pip install -e .

Quick Start

Open a notebook on http://localhost:8770:

notebook-viewer --notebook analysis.ipynb --port 8770

Restrict the viewer to a specific project directory:

notebook-viewer --root ~/projects/my-analysis --notebook notebooks/report.ipynb --port 8770

Start without opening a browser:

notebook-viewer --root . --notebook analysis.ipynb --port 8770 --no-browser

Stop a foreground server with Ctrl-C.

CLI

notebook-viewer [--root ROOT] [--notebook NOTEBOOK] [--host HOST] [--port PORT] [--no-browser]

Options:

• --root: directory that readable notebooks must stay inside, default .
• --notebook: notebook path relative to --root
• --host: bind host, default 0.0.0.0
• --port: bind port, default 8770
• --no-browser: do not open a browser automatically

How It Works

The viewer parses saved notebook JSON with the Python standard library and caches parsed notebooks by path, mtime, and size. Markdown headings define the outline. Selecting or scrolling to a section loads the cells for that section, while image and video outputs are represented as asset descriptors and streamed separately from /api/asset/<asset_id>.

Supported output behavior:

• PNG, JPEG, GIF, SVG, and common video MIME outputs become lazy asset URLs.
• HTML video data URLs are extracted into streamed video assets.
• HTML tables and rich HTML outputs are sanitized before rendering.
• stdout, stderr, tracebacks, and unsupported widgets use readable fallback blocks.
• Code cells include raw source and highlighted HTML in the section API.

API

The local server exposes a small JSON/asset API:

• GET /api/notebooks: list .ipynb files under --root
• GET /api/notebook?path=...: return outline and section metadata
• GET /api/section?path=...&section=...: return cells for one section
• GET /api/asset/<asset_id>: stream decoded media assets

Notebook and section JSON responses avoid embedding large base64 media payloads.

Security Notes

ipynb-local-viewer is a local reader, not a notebook execution environment.

• It never runs notebook code.
• It restricts notebook access to the configured --root.
• It sanitizes markdown-rendered HTML and notebook HTML outputs.
• It serves decoded media assets from .notebook_viewer_cache/.

As with any local web server, bind it only where you intend to expose it. The default host is 0.0.0.0; use --host 127.0.0.1 for loopback-only access.

Development

Install development tools and run the test suite:

python -m pip install -e .
python -m pip install build twine trove-classifiers tomli
python -m unittest discover -s tests
python -m compileall src

Build and validate distribution artifacts:

python -m build
python -m twine check dist/*
python scripts/check_classifiers.py

Publishing

Releases are intended to use PyPI Trusted Publishing from GitHub Actions.

One-time PyPI setup:

1. Log into the PyPI account masoudka.
2. Create or select the PyPI project ipynb-local-viewer.
3. Add a pending trusted publisher for:
   • Owner: msdkhairi
   • Repository: ipynb-viewer
   • Workflow: release.yml
   • Environment: pypi

Owner is the GitHub repository owner, not the PyPI username. The GitHub repository can remain ipynb-viewer even though the PyPI distribution name is ipynb-local-viewer.

Release flow:

git tag v0.1.0
git push origin v0.1.0

Then create a GitHub release for that tag. The release workflow builds the artifacts, validates them, and publishes with PyPI Trusted Publishing.

Manual fallback:

python -m build
python -m twine check dist/*
python -m twine upload dist/*

License

ipynb-local-viewer is distributed under the MIT License. See LICENSE.