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This example demonstrates building a basic calculator workflow with number inputs, math operations, and result display.

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Overview

We’ll create a workflow that:
  1. Takes two number inputs
  2. Performs addition and multiplication
  3. Displays the results

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Node Definitions

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NumberInputNode

import { Node, defineNode, Property, Output } from '@crystalflow/core';

@defineNode({
  type: 'input.number',
  label: 'Number Input',
  category: 'Input'
})
export class NumberInputNode extends Node {
  @Property({
    type: 'number',
    label: 'Value',
    defaultValue: 0,
    step: 1
  })
  value: number = 0;

  @Output({ type: 'number', label: 'Value' })
  output: number;

  execute() {
    this.output = this.value;
  }
}

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AddNode

import { Node, defineNode, Input, Output } from '@crystalflow/core';

@defineNode({
  type: 'math.add',
  label: 'Add',
  category: 'Math'
})
export class AddNode extends Node {
  @Input({ type: 'number', label: 'A' })
  a: number = 0;

  @Input({ type: 'number', label: 'B' })
  b: number = 0;

  @Output({ type: 'number', label: 'Result' })
  result: number;

  execute() {
    this.result = this.a + this.b;
  }
}

​
MultiplyNode

import { Node, defineNode, Input, Output } from '@crystalflow/core';

@defineNode({
  type: 'math.multiply',
  label: 'Multiply',
  category: 'Math'
})
export class MultiplyNode extends Node {
  @Input({ type: 'number', label: 'A' })
  a: number = 0;

  @Input({ type: 'number', label: 'B' })
  b: number = 0;

  @Output({ type: 'number', label: 'Result' })
  result: number;

  execute() {
    this.result = this.a * this.b;
  }
}

​
DisplayNode

import { Node, defineNode, Input } from '@crystalflow/core';

@defineNode({
  type: 'output.display',
  label: 'Display',
  category: 'Output'
})
export class DisplayNode extends Node {
  @Input({ type: 'any', label: 'Value' })
  value: any = null;

  execute() {
    console.log('Display:', this.value);
  }
}

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Building the Workflow

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Programmatic Creation

import { Workflow } from '@crystalflow/core';
import { NumberInputNode, AddNode, MultiplyNode, DisplayNode } from './nodes';

// Create workflow
const workflow = new Workflow('math-workflow', 'Math Calculator');

// Add number inputs
const num1 = workflow.addNode(NumberInputNode, {
  position: { x: 100, y: 100 },
  data: { value: 5 }
});

const num2 = workflow.addNode(NumberInputNode, {
  position: { x: 100, y: 250 },
  data: { value: 3 }
});

// Add math operations
const add = workflow.addNode(AddNode, {
  position: { x: 350, y: 100 }
});

const multiply = workflow.addNode(MultiplyNode, {
  position: { x: 350, y: 250 }
});

// Add displays
const display1 = workflow.addNode(DisplayNode, {
  position: { x: 600, y: 100 }
});

const display2 = workflow.addNode(DisplayNode, {
  position: { x: 600, y: 250 }
});

// Connect nodes
workflow.connect(num1.id, 'output', add.id, 'a');
workflow.connect(num2.id, 'output', add.id, 'b');
workflow.connect(add.id, 'result', display1.id, 'value');

workflow.connect(num1.id, 'output', multiply.id, 'a');
workflow.connect(num2.id, 'output', multiply.id, 'b');
workflow.connect(multiply.id, 'result', display2.id, 'value');

// Execute workflow
const result = await workflow.execute();

console.log('Execution status:', result.status);
console.log('Duration:', result.duration, 'ms');

// Get results
result.nodeResults.forEach((nodeResult, nodeId) => {
  console.log(`Node ${nodeId}:`, nodeResult.outputs);
});
Output: 
Display: 8
Display: 15
Execution status: success
Duration: 5 ms
Node add-1: { result: 8 }
Node multiply-1: { result: 15 }

​
React Component

import React from 'react';
import { WorkflowBuilder } from '@crystalflow/react';
import { NumberInputNode, AddNode, MultiplyNode, DisplayNode } from './nodes';

function MathCalculator() {
  const nodes = [NumberInputNode, AddNode, MultiplyNode, DisplayNode];

  const handleExecute = (result) => {
    console.log('Workflow executed:', result);
    
    // Extract results
    result.nodeResults.forEach((nodeResult, nodeId) => {
      if (nodeResult.outputs.result !== undefined) {
        console.log('Result:', nodeResult.outputs.result);
      }
    });
  };

  return (
    <div className="calculator">
      <h1>Math Calculator</h1>
      <WorkflowBuilder
        nodes={nodes}
        onExecute={handleExecute}
        showNodePalette={true}
        showPropertyPanel={true}
        showToolbar={true}
        style={{ height: '600px' }}
      />
    </div>
  );
}

export default MathCalculator;

​
JSON Workflow

Save the workflow as JSON: 
{
  "version": "1.0.0",
  "id": "math-workflow",
  "name": "Math Calculator",
  "nodes": [
    {
      "id": "num1",
      "type": "input.number",
      "position": { "x": 100, "y": 100 },
      "data": {
        "properties": { "value": 5 },
        "inputs": {},
        "outputs": {}
      }
    },
    {
      "id": "num2",
      "type": "input.number",
      "position": { "x": 100, "y": 250 },
      "data": {
        "properties": { "value": 3 },
        "inputs": {},
        "outputs": {}
      }
    },
    {
      "id": "add",
      "type": "math.add",
      "position": { "x": 350, "y": 100 },
      "data": {
        "properties": {},
        "inputs": {},
        "outputs": {}
      }
    },
    {
      "id": "multiply",
      "type": "math.multiply",
      "position": { "x": 350, "y": 250 },
      "data": {
        "properties": {},
        "inputs": {},
        "outputs": {}
      }
    }
  ],
  "connections": [
    {
      "id": "conn1",
      "source": "num1",
      "sourcePort": "output",
      "target": "add",
      "targetPort": "a"
    },
    {
      "id": "conn2",
      "source": "num2",
      "sourcePort": "output",
      "target": "add",
      "targetPort": "b"
    },
    {
      "id": "conn3",
      "source": "num1",
      "sourcePort": "output",
      "target": "multiply",
      "targetPort": "a"
    },
    {
      "id": "conn4",
      "source": "num2",
      "sourcePort": "output",
      "target": "multiply",
      "targetPort": "b"
    }
  ],
  "variables": {}
}

​
With Event Handlers

Add detailed event tracking: 
import { Executor } from '@crystalflow/core';

const executor = new Executor();

// Track node execution
executor.on('onNodeStart', (nodeId, node) => {
  console.log(`⚙️  Executing ${node.metadata.label} (${nodeId})`);
});

executor.on('onNodeComplete', (nodeId, result) => {
  console.log(`✅ ${nodeId} completed:`, result.outputs);
});

// Execute
await executor.execute(workflow);
Output: 
⚙️  Executing Number Input (num1)
✅ num1 completed: { output: 5 }
⚙️  Executing Number Input (num2)
✅ num2 completed: { output: 3 }
⚙️  Executing Add (add)
✅ add completed: { result: 8 }
⚙️  Executing Multiply (multiply)
✅ multiply completed: { result: 15 }

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Key Concepts

Uses @Property decorator for static configuration. The value is set in the property panel, not connected from another node.
Use @Input decorators for dynamic data flow. Values come from connected nodes via handles.
Connect output ports to input ports. Data flows automatically during execution.
Nodes execute in topological order. num1 and num2 first, then add and multiply.

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Next Steps

Data Processing

Work with arrays and data transformation

Conditional Logic

Add branching and conditions

Creating Custom Nodes

Build your own nodes

Quick Start

5-minute tutorial