Function NodeTypeCode: function

When to Use

• Complex multi-step processing pipelines: An order enrichment function fetches pricing tiers, applies discounts, calculates tax, and assembles a complete order summary object — all in a single Function node with a 30-second timeout allowance.
• Multi-field result expansion: Unlike CodeExecute (which wraps result in a single result field), Function allows the script to return an object whose properties become individual OutputData fields. Downstream nodes access {{ $output.fnNode.orderId }}, {{ $output.fnNode.total }}, {{ $output.fnNode.itemCount }} directly without nested access.
• Long-running data processing with custom timeouts: Processing a large dataset may legitimately take 15-30 seconds. CodeExecute's hard 5-second limit is too restrictive. Function's configurable Timeout allows this safely.
• Pricing engine implementation: A multi-tier pricing calculation with volume discounts, currency conversion, and margin floor enforcement is best expressed in JavaScript. The Function node handles the complete calculation and returns a structured result object.
• Multi-field data validation returning structured errors: A form submission validator checks 10 fields and returns both a valid flag and a detailed errors array. Result expansion makes both fields directly accessible downstream.

Function vs CodeExecute

Configuration

Result Expansion Behaviour

Output Ports

Sample Script — Order Summary with Result Expansion

// input is available as the workflow's current InputData
// Workflow variables (orderItems, customerId) injected as globals
var items = orderItems;  // array of { productId, price, quantity }
var subtotal = items.reduce(function(sum, item) {
  return sum + (item.price * item.quantity);
}, 0);
var tax = subtotal * 0.15;
var total = subtotal + tax;

// Assign an OBJECT to result — properties expand to individual output fields
result = {
  orderId:    input.orderId,
  customerId: customerId,
  itemCount:  items.length,
  subtotal:   Math.round(subtotal * 100) / 100,
  tax:        Math.round(tax * 100) / 100,
  total:      Math.round(total * 100) / 100,
  currency:   input.currency || "USD"
};

Downstream expressions: {{ $output.orderSummaryFn.total }}, {{ $output.orderSummaryFn.itemCount }}, {{ $output.orderSummaryFn.orderId }} — all available as direct fields.

Sample Script — Multi-Field Validation

// formData injected as a workflow variable
var form = formData;
var errors = [];
if (!form.firstName || form.firstName.trim().length < 2) {
  errors.push({ field: "firstName", message: "First name must be at least 2 characters." });
}
if (!form.email || !/^[^\s@]+@[^\s@]+\.[^\s@]+$/.test(form.email)) {
  errors.push({ field: "email", message: "A valid email address is required." });
}
if (!form.phone || !/^\+?[\d\s\-]{7,15}$/.test(form.phone)) {
  errors.push({ field: "phone", message: "Phone number format is invalid." });
}
result = {
  valid: errors.length === 0,
  errorCount: errors.length,
  errors: errors,
  submittedBy: form.submittedBy
};

Sample Script — Pricing Engine with Tiered Discounts

// orderLines injected from workflow variable; customerTier injected as string
var lines = orderLines;
var tier = customerTier;
var subtotal = lines.reduce(function(s, l) { return s + l.unitPrice * l.qty; }, 0);

var discountRate = 0;
if (tier === "platinum") { discountRate = 0.20; }
else if (tier === "gold") { discountRate = 0.12; }
else if (tier === "silver") { discountRate = 0.05; }

var discount  = Math.round(subtotal * discountRate * 100) / 100;
var afterDisc = subtotal - discount;
var vat       = Math.round(afterDisc * 0.20 * 100) / 100;
var grandTotal= Math.round((afterDisc + vat) * 100) / 100;

result = {
  subtotal:     subtotal,
  discountRate: discountRate,
  discountAmt:  discount,
  vatAmt:       vat,
  grandTotal:   grandTotal,
  currency:     "GBP"
};

Sample Configuration

{
  "functionCode": "// Transform customer records for CRM sync\nconst records = items.map(item => ({\n  externalId: item.json.id,\n  fullName: `${item.json.firstName} ${item.json.lastName}`,\n  email: item.json.email.toLowerCase(),\n  tier: item.json.totalSpend > 10000 ? 'gold' : 'standard',\n  syncedAt: new Date().toISOString()\n}));\nreturn records.map(r => ({ json: r }));",
  "timeout": 10000
}

Sample Output

Success Port

{
  "externalId": "cust_00451",
  "fullName": "Alice Chen",
  "email": "alice.chen@acmecorp.com",
  "tier": "gold",
  "syncedAt": "2025-03-15T10:30:00.000Z"
}

Expression Reference

Node Policies & GuardRails