@jupyter-kit/editor-codemirror

CodeMirror 6 editor plugin. Replaces static <pre> code displays with a live editor per code cell. Adds a cell toolbar (run / add / delete).

createEditorPlugin() is installed transitively by both @jupyter-kit/executor-pyodide and @jupyter-kit/executor-webr — you only install it directly if you want editable cells without an executor.

EditorCodemirrorOptions

Option	Type	Default	Notes
languages	Record<string, Extension>	{}	Per-language CodeMirror extensions. Keys match cell language strings; '*' is fallback. Example: { python: python() }.
extensions	Extension[]	[]	Extra extensions applied to every editor (theme, keymap, linting …).
readOnly	boolean	false	Render editors as read-only. Hides the Run / Add / Delete toolbar.
lineNumbers	boolean	false	Show gutter line numbers.
fontFamily	string	ui-monospace stack	Editor font.
fontSize	string	'inherit'	CSS font-size value.
backgroundColor	string	'transparent'	Editor background.
focusBorderColor	string	semi-transparent blue	Left border when focused.
inactiveBorderColor	string	'transparent'	Left border when blurred.
runButton	boolean	true	Show the ▶ run button (only when executor is set).
runLabel	string	'Run (Shift+Enter)'	Tooltip for the run button.

Usage

import { createEditorPlugin } from '@jupyter-kit/editor-codemirror';
import { python } from '@codemirror/lang-python';
import { StreamLanguage } from '@codemirror/language';
import { r } from '@codemirror/legacy-modes/mode/r';
import { EditorView } from '@codemirror/view';

const plugin = createEditorPlugin({
  languages: {
    python: python(),
    r: StreamLanguage.define(r),
  },
  extensions: [EditorView.lineWrapping],
  lineNumbers: true,
});

Keybindings

Keys	Effect
Shift+Enter	Run the current cell and focus the next code cell.
Cmd/Ctrl+Z / Shift+Cmd/Ctrl+Z	Undo / redo (within a cell).
Cmd/Ctrl+S	Download the notebook (see onSave).

Toolbar buttons

Visible on hover / focus of a code cell:

• ▶ Run — runs the cell via ctx.executor?.rerun. Only rendered when an executor is present and runButton: true.
• + Add cell below — inserts an empty cell of the same type.
• 🗑 Delete cell — removes the cell.