Notebook Assets Renderer

Preview notebook-relative DataFrame HTML files directly in VS Code notebooks without embedding the full HTML document in the .ipynb file.

Features

• Renders application/vnd.notebook-assets.dataframe+json outputs inline.
• Keeps large pandas HTML previews outside the notebook for smaller diffs and coding-agent-friendly files.
• Preserves pandas and Styler CSS while matching VS Code's native notebook table appearance.
• Supports notebook-relative paths on local, remote, and virtual file systems through the VS Code workspace file-system API.
• Removes scripts, iframes, forms, event handlers, and external resource URLs before inserting HTML into the notebook output.

Requirements

• VS Code 1.100 or later.
• A notebook output producer that emits the MIME descriptor below. In Jupyter, this is typically Python with IPython and pandas.
• A trusted workspace. The extension reads HTML files referenced by notebook outputs and is disabled in Restricted Mode.

Descriptor format

The custom MIME type is:

application/vnd.notebook-assets.dataframe+json

Its JSON value can contain:

{
  "version": 1,
  "kind": "dataframe",
  "shape": [1000, 20],
  "html": "assets/example.ipynb/result.html",
  "mtime_ns": 1750000000000000000,
  "data": {
    "parquet": "assets/example.ipynb/result.parquet"
  }
}

Only html is required by the renderer. The path must be relative to the notebook's directory. Absolute paths, URI schemes, .., query strings, and fragments are rejected.

Python example

Write the rich HTML next to the notebook and emit only its relative path:

from pathlib import Path
from IPython.display import display

MIME = "application/vnd.notebook-assets.dataframe+json"
html_path = Path("assets/example.ipynb/result.html")
html_path.parent.mkdir(parents=True, exist_ok=True)
html_path.write_text(df._repr_html_(), encoding="utf-8")

display(
    {
        MIME: {
            "version": 1,
            "kind": "dataframe",
            "shape": list(df.shape),
            "html": html_path.as_posix(),
        },
        "text/plain": repr(df),
    },
    raw=True,
)

Keep a text/plain fallback so the output remains readable when the extension is unavailable.

Security and privacy

HTML assets are read only after Workspace Trust is granted. Active content and external resource references are removed before rendering. The extension does not execute notebook code, send telemetry, or transmit files over the network.

Known limitations

• The extension currently renders external HTML previews only.
• JavaScript and interactive HTML widgets are intentionally not supported.
• The referenced asset must remain available relative to the notebook.

Support

Use the Q & A section on this extension's Marketplace page for usage questions and bug reports. Include your VS Code version, operating system, workspace type, trust status, sanitized MIME descriptor, and the exact renderer error. Do not include private notebook contents or credentials.

License

Copyright © 2026 GrayF. All rights reserved. The full license is included in the extension package.