Framework
- Jupyter
- Jupyter :: JupyterLab
- Jupyter :: JupyterLab :: 4
- Jupyter :: JupyterLab :: Extensions
- Jupyter :: JupyterLab :: Extensions :: Prebuilt
Programming Language
- Python
- Python :: 3
- Python :: 3.10
- Python :: 3.11
- Python :: 3.12
- Python :: 3.13
- Python :: 3.14
jupyter_live_content
A JupyterLab extension that keeps open documents in sync with their file on disk. When a file changes on disk while you have it open — for example, an AI agent or another process rewrites it — this extension reloads the document in the browser so what you see stays current, without requiring real-time collaboration (RTC).
This extension is composed of a Python package named jupyter_live_content
for the server extension and a NPM package named @jupyter-ai-contrib/live-content
for the frontend extension.
How it works
The server extension watches the content directory for filesystem changes and
notifies the browser over a WebSocket when a file you have open changes. The
frontend then reloads that document from disk (context.revert()), but only for
documents where a whole-file reload is safe.
Reloading is deliberately conservative. It is applied only to documents whose view is a pure function of the file's bytes, so a reload cannot destroy in-memory state. This is an allowlist: any document type not listed below is left untouched rather than reloaded.
What gets updated
| Document | Updated live? | Notes |
|---|---|---|
Text / code / Markdown in a file editor (FileEditor) |
Yes | Reloads the text buffer. Includes a notebook opened via Open With → Editor. |
Markdown preview (MarkdownViewer) |
Yes | Re-renders from the reloaded text. |
Images (ImageViewer) |
Yes | Re-renders the image. |
| A document with unsaved changes (dirty) | No | Your edits are never clobbered; JupyterLab's save-conflict dialog resolves the divergence when you next save. |
| Notebooks (the notebook view) | No | Reverting would discard outputs, execution counts, cell IDs, and the running-kernel association. This holds even for a read-only notebook, since read-only blocks saving but not running cells. |
| Collaborative / RTC-backed documents (JupyterGIS, JupyterCAD, chat files, …) | No | The document's own provider owns synchronization. |
| Any other / third-party document type | No | Excluded by default (allowlist). |
Real-time collaboration (RTC)
If an RTC provider (jupyter_server_ydoc / Jupyter Collaboration, or
jupyter_server_documents) is installed and enabled, RTC already keeps open
documents in sync, so this extension disables itself entirely: the server does
not watch the filesystem or open a WebSocket, and the frontend does not connect.
If a provider is installed but disabled (via jupyter server extension disable
or the disable_rtc trait), this extension stays active.
Future work
- Notebooks. Reliably reconciling an out-of-band notebook edit with live in-memory state (so a benign change to one cell doesn't blow away work in another) is unsolved. See the discussion in #2 and #5.
- More viewer types. Other read-only viewers (CSV/TSV, etc.) could be added to the allowlist as their reload behavior is validated.
- PDFs. JupyterLab 4 ships no built-in PDF document-widget viewer, so there is currently no PDF surface to update; a custom viewer would need to opt in.
Requirements
- JupyterLab >= 4.0.0
Install
To install the extension, execute:
pip install jupyter_live_content
Uninstall
To remove the extension, execute:
pip uninstall jupyter_live_content
Troubleshoot
If you are seeing the frontend extension, but it is not working, check that the server extension is enabled:
jupyter server extension list
If the server extension is installed and enabled, but you are not seeing the frontend extension, check the frontend extension is installed:
jupyter labextension list
Contributing
If you would like to contribute to this extension, please refer to the Contributing Guide.
