PyNodeWidget

A Python wrapper for ReactFlow using AnyWidget - build interactive node graphs without JavaScript.

Quick Start

from pynodewidget import NodeFlowWidget
from pynodewidget.grid_layouts import create_three_column_grid
from pynodewidget.models import ButtonHandle, NumberField, LabeledHandle, TextField

widget = NodeFlowWidget()

grid_layout = create_three_column_grid(
    left_components=[
        LabeledHandle(id="input", handle_type="input")
    ],
    center_components=[
        NumberField(id="value", value=50, min=0, max=100),
        TextField(id="name", value="Processor")
    ],
    right_components=[
        LabeledHandle(id="output", handle_type="output")
    ]
)

widget.add_node_type(
    type_name="processor",
    label="Processor",
    icon="⚙️",
    grid_layout=grid_layout
)
widget

Demo

Features

• Interactive Node Graphs: Build visual workflows with drag-and-drop nodes
• No JavaScript Required: Pure Python API for defining node types and layouts
• JSON Schema Integration: Automatically generate node UIs from JSON schemas
• Static HTML Export: Export workflows as standalone HTML files for documentation and sharing
  • Interactive or view-only modes
  • Self-contained files that work without Python/Jupyter
  • Perfect for visualizing DAGs and data pipelines
• Jupyter & Marimo Support: Works seamlessly in Jupyter notebooks and Marimo apps
• Flexible Layouts: Customizable grid-based node layouts with various components
• Type-Safe: Built with Pydantic for robust type validation

Export Workflows

# Export as standalone HTML (no Python required to view)
widget.export_html("workflow.html", interactive=True)

# Export as JSON for persistence
widget.export_json("workflow.json")

Development

Requires:

• Python 3.12+ (uv)
• Bun for JavaScript bundling

# Install dependencies
uv venv
uv pip install -e .[all]

task

Documentation

# Serve documentation locally with live reload
task docs-serve

# Build static documentation
task docs-build

See full documentation at the project's GitHub Pages or run locally.