Code

Write JavaScript or Python code directly from within your workflow.

Overview

Use the Code node to process workflow data directly with custom JavaScript or Python code. Choose it when standard nodes are not enough, for example for calculations, formatting, validation, file processing, or custom business logic.

When to Use Code Node

Code nodes are perfect for:

• Data transformations and formatting
• Mathematical calculations
• Custom business logic
• JSON parsing and manipulation
• Data validation and cleaning
• Date/time operations
• File processing with Python

What code nodes are not ideal for:

• AI analysis (use Agent node)
• External API calls (use HTTP Request node)
• Simple conditions (use Condition node)
• Long-running or interactive analysis (use Data Analysis)

Configuration

Language: Choose whether to write your code in JavaScript or Python.

Code Editor: Write your transformation logic in the selected language in the code editor that opens when you select the Code node.

Access Previous Nodes: Outputs from previous nodes are available as variables in the Code node. The available variable names are shown at the top of the code editor. To use the Code node output later, see Accessing Code Output.

Examples

Calculate Statistics

JavaScript

// Access data from previous nodes
const scores = agent.output.structured.scores || [];

// Calculate statistics
const average = scores.reduce((a, b) => a + b, 0) / scores.length;
const max = Math.max(...scores);
const min = Math.min(...scores);

// Return result
return {
  average_score: average.toFixed(2),
  highest_score: max,
  lowest_score: min,
  grade: average >= 90 ? "A" : average >= 80 ? "B" : "C"
};

Validate and Clean Data

JavaScript

// Access form data
const email = trigger.output.email || "";
const amount = trigger.output.amount || 0;

// Validate
if (!email.includes("@")) {
  throw new Error("Invalid email format");
}

if (amount <= 0) {
  throw new Error("Amount must be greater than zero");
}

// Clean and return
return {
  email: email.trim().toLowerCase(),
  amount: parseFloat(amount.toFixed(2)),
  validated: true
};

Transform and Filter Arrays

JavaScript

// Access data from previous node
const customers = trigger.output.customers || [];

// Filter active customers
const activeCustomers = customers.filter(c => c.status === "active");

// Transform data
const processed = activeCustomers.map(customer => ({
  id: customer.id,
  name: `${customer.firstName} ${customer.lastName}`.trim(),
  email: customer.email.toLowerCase(),
  tier: customer.totalSpent > 1000 ? "premium" : "standard"
}));

return {
  customers: processed,
  total: processed.length,
  premiumCount: processed.filter(c => c.tier === "premium").length
};

Date Operations

JavaScript

// Access event data
const events = trigger.output.events || [];
const now = new Date();

const processedEvents = events.map(event => {
  const eventDate = new Date(event.date);
  const daysUntil = Math.ceil((eventDate - now) / (1000 * 60 * 60 * 24));

  return {
    title: event.title,
    date: eventDate.toISOString(),
    formatted: eventDate.toLocaleDateString("en-US", {
      weekday: "long",
      year: "numeric",
      month: "long",
      day: "numeric"
    }),
    daysUntil: daysUntil,
    isUpcoming: daysUntil >= 0,
    isThisWeek: daysUntil >= 0 && daysUntil <= 7
  };
});

return {
  events: processedEvents,
  upcomingCount: processedEvents.filter(e => e.isUpcoming).length,
  thisWeekCount: processedEvents.filter(e => e.isThisWeek).length
};

JSON Processing

JavaScript

// Nested JSON from API response
const apiResponse = http_request.output || {};

// Extract and flatten nested data
const users = apiResponse.data?.users || [];

const flattened = users.map(user => ({
  id: user.id,
  name: `${user.first_name || ""} ${user.last_name || ""}`.trim(),
  email: user.contact?.email || "",
  city: user.address?.city || "Unknown",
  isActive: user.status === "active"
}));

return {
  users: flattened,
  total: flattened.length,
  activeCount: flattened.filter(u => u.isActive).length
};

Aggregate and Summarize

JavaScript

// Sales data from previous node
const sales = http_request.output.sales || [];

// Group by category
const byCategory = {};
sales.forEach(sale => {
  const cat = sale.category || "Other";
  if (!byCategory[cat]) {
    byCategory[cat] = { total: 0, count: 0, items: [] };
  }
  byCategory[cat].total += sale.amount || 0;
  byCategory[cat].count += 1;
  byCategory[cat].items.push(sale);
});

// Calculate summary
const summary = Object.entries(byCategory).map(([category, data]) => ({
  category,
  totalRevenue: data.total.toFixed(2),
  orderCount: data.count,
  averageOrder: (data.total / data.count).toFixed(2)
}));

// Sort by revenue
summary.sort((a, b) => parseFloat(b.totalRevenue) - parseFloat(a.totalRevenue));

return {
  summary: summary,
  topCategory: summary[0]?.category || "None",
  grandTotal: sales.reduce((sum, s) => sum + (s.amount || 0), 0).toFixed(2)
};

Create a File with Python

Files created by Python in the working directory are attached to the node output under _files.

Python

import csv

customers = trigger.get("output", {}).get("customers", [])
active_customers = [c for c in customers if c.get("status") == "active"]

with open("active_customers.csv", "w", newline="") as file:
    writer = csv.DictWriter(file, fieldnames=["id", "email"])
    writer.writeheader()

    for customer in active_customers:
        writer.writerow({
            "id": customer.get("id"),
            "email": customer.get("email", "").lower()
        })

print(f"Created CSV with {len(active_customers)} customers")

return {
    "active_count": len(active_customers),
    "file_name": "active_customers.csv"
}

Accessing Code Output

Use the Code node name to access returned values from JavaScript or Python in subsequent nodes:

{{code_node_name.output.customer}}
{{code_node_name.output.total}}
{{code_node_name.output.formatted_date}}
{{code_node_name.output.processed_items[0].name}}

Files created by Python in the working directory are available under _files:

{{code_node_name.output._files[0]._metadata.name}}

Language Capabilities

Code node capabilities depend on the selected language.

JavaScript

JavaScript runs in a secure sandbox environment with built-in utility functions:

• ld.request(): Make HTTP requests
• ld.log(): Output debugging information
• Data conversions: CSV, Parquet, Arrow format conversions
• Standard JavaScript: JSON, Date, Math, Array, Object methods

Complete Utilities Reference

View all available sandbox utilities including data conversions, SQL validation, cryptography, and more.

Python

Python runs in a sandboxed environment without internet access.

• Use top-level return to set the node output
• Use print() to write logs
• Use preinstalled data and document libraries such as pandas, numpy, openpyxl, and pypdf
• Access previous node outputs as variables when their slugs are valid Python identifiers
• Read workflow attachments from the working directory
• Save files in the working directory to expose them under _files
• Run without internet access

The JavaScript ld.* utilities are not available in Python.

Best Practices

Return Structured Objects

Return data as objects for easy access in later nodes. This makes it simple to reference specific values in subsequent nodes using dot notation.

Handle Missing Data

Use ||, optional chaining (?.), or Python .get() to provide default values and prevent errors when data is undefined or null.

Use Error Handling

Wrap risky operations in try/catch for JavaScript or try/except for Python. This helps prevent workflow failures and provides meaningful error messages.

Keep It Simple

Complex logic might be better in an Agent node. Use code nodes for straightforward transformations and calculations, not for tasks requiring intelligence or context understanding.

Add Comments

Document what your code does for future reference. Clear comments help you and your team understand the logic when revisiting the workflow later.

Next Steps

Agent

Use AI for intelligent processing

HTTP Request

Fetch external data

Data Analysis

Analyze data with an Agent