Zasper 1.0.0

10 September 2026 · Prasun Anand

Zasper 1.0.0 is the first stable release. From this version on, Zasper’s HTTP and WebSocket API, its configuration file and its command-line flags follow semantic versioning: they will not break within 1.x.

brew install zasper-io/tap/zasper     # macOS
sudo snap install zasper              # Linux
conda install zasper -c conda-forge   # anywhere conda runs

Prebuilt binaries for macOS, Linux and Windows are on the Downloads page.

What’s New

Source control. A Git panel with real status, staging, discard and commits of staged changes only; creating, switching and deleting branches; syncing with a remote; a readable history; side-by-side diffs; and git init for a folder that isn’t a repository yet.

Notebook outputs. ipywidgets, Plotly figures, GitHub Flavored Markdown with tables, and LaTeX in markdown cells through KaTeX.

Notebook editing. Reordering cells from the keyboard, insert options and context menus, autocompletion from the kernel, and a dialog that catches unsaved changes when you close a tab.

Notebooks round-trip exactly. Notebooks in formats 2 and 3 are converted to 4.5 when opened, 4.x files keep their own minor version when saved, and a saved notebook is byte-for-byte what Jupyter would have written. Saves are atomic, so a crash or a full disk can’t leave a truncated notebook. Notebook Support has the details.

Terminals that open in your project folder, and a command palette that searches files and every command in one place.

Nine themes, all built from one set of design tokens, and zoom for the whole window.

Logging that stays out of the way. Readable output in a terminal, JSON for a log collector, and by default only what changed or failed.

Upgrading from 0.2.0-beta

• The server binds 127.0.0.1 by default instead of every interface. To reach Zasper from another machine, start it with --host=0.0.0.0 and turn on protected mode. (From 1.1.0, protected mode is always on; see Deploying on Cloud.)
• The Electron desktop app is gone. Zasper is a local server you open in your browser.
• DELETE /ws/kernels/{kernel_id} has been removed. Use DELETE /api/kernels/{kernelId}.
• Kernel connection files moved to ~/.zasper/runtime, readable only by you and deleted when the kernel stops.
• Zasper sends anonymous usage data unless you turn it off with --tracking=false; Configuration lists exactly what is sent.

The changelog has the complete list, including the security fixes in this release.