React Flow

React Flow (@xyflow/react) is a library for building node-based graphs, workflow editors, and interactive diagrams. It provides a highly customizable framework for creating visual programming interfaces, process flows, and network visualizations.

Quick Start

Installation

pnpm add @xyflow/react

Basic Setup

import { ReactFlow, Node, Edge, Background, Controls, MiniMap } from '@xyflow/react';
import '@xyflow/react/dist/style.css';

const initialNodes: Node[] = [
  {
    id: '1',
    type: 'input',
    data: { label: 'Input Node' },
    position: { x: 250, y: 5 },
  },
  {
    id: '2',
    data: { label: 'Default Node' },
    position: { x: 100, y: 100 },
  },
  {
    id: '3',
    type: 'output',
    data: { label: 'Output Node' },
    position: { x: 400, y: 100 },
  },
];

const initialEdges: Edge[] = [
  { id: 'e1-2', source: '1', target: '2', animated: true },
  { id: 'e2-3', source: '2', target: '3' },
];

function Flow() {
  return (
    <div style={{ width: '100vw', height: '100vh' }}>
      <ReactFlow nodes={initialNodes} edges={initialEdges}>
        <Background />
        <Controls />
        <MiniMap />
      </ReactFlow>
    </div>
  );
}

export default Flow;

Core Concepts

Nodes

Nodes are the building blocks of the graph. Each node has:

• id: Unique identifier
• type: Node type (built-in or custom)
• position: { x, y } coordinates
• data: Custom data object

import { Node } from '@xyflow/react';

const node: Node = {
  id: 'node-1',
  type: 'default',
  position: { x: 100, y: 100 },
  data: { label: 'Node Label' },
  style: { background: '#D6D5E6' },
  className: 'custom-node',
};

Built-in node types:

• default: Standard node
• input: No target handles
• output: No source handles
• group: Container for other nodes

Edges

Edges connect nodes. Each edge requires:

• id: Unique identifier
• source: Source node ID
• target: Target node ID

import { Edge } from '@xyflow/react';

const edge: Edge = {
  id: 'e1-2',
  source: '1',
  target: '2',
  type: 'smoothstep',
  animated: true,
  label: 'Edge Label',
  style: { stroke: '#fff', strokeWidth: 2 },
};

Built-in edge types:

• default: Bezier curve
• straight: Straight line
• step: Orthogonal with sharp corners
• smoothstep: Orthogonal with rounded corners

Handles

Handles are connection points on nodes. Use Position enum for placement:

import { Handle, Position } from '@xyflow/react';

<Handle type="target" position={Position.Top} />
<Handle type="source" position={Position.Bottom} />

Available positions: Position.Top, Position.Right, Position.Bottom, Position.Left

State Management

Controlled Flow

Use state hooks for full control:

import { useNodesState, useEdgesState, addEdge, OnConnect } from '@xyflow/react';
import { useCallback } from 'react';

function ControlledFlow() {
  const [nodes, setNodes, onNodesChange] = useNodesState(initialNodes);
  const [edges, setEdges, onEdgesChange] = useEdgesState(initialEdges);

  const onConnect: OnConnect = useCallback(
    (connection) => setEdges((eds) => addEdge(connection, eds)),
    [setEdges]
  );

  return (
    <ReactFlow
      nodes={nodes}
      edges={edges}
      onNodesChange={onNodesChange}
      onEdgesChange={onEdgesChange}
      onConnect={onConnect}
    />
  );
}

useReactFlow Hook

Access the React Flow instance for programmatic control:

import { useReactFlow } from '@xyflow/react';

function FlowControls() {
  const {
    getNodes,
    getEdges,
    setNodes,
    setEdges,
    addNodes,
    addEdges,
    deleteElements,
    fitView,
    zoomIn,
    zoomOut,
    getNode,
    getEdge,
    updateNode,
    updateEdge,
  } = useReactFlow();

  return (
    <button onClick={() => fitView()}>Fit View</button>
  );
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