Custom Transformations allow you to apply complex data transformations to your CSV and JSON files using JavaScript. The feature now includes AI-powered code generation and support for multiple input and output files , making it easier to create sophisticated data processing workflows without manual coding.
Generate transformation code automatically by describing what you want to accomplish in plain English. The AI understands your requirements and creates production-ready JavaScript code.
Process multiple CSV or JSON files simultaneously in a single transformation. Each file can be referenced by a custom variable name in your code.
Create multiple output files from a single transformation. Split your data by category, create summary reports, or generate different views of your data—all in one operation.
Access powerful data manipulation libraries:
Lodash : Comprehensive utility functions for data transformation
Day.js : Modern date and time manipulation
Navigate to the Custom Transformations section
Click Add Transformation
The transformation builder modal will open
File Selection:
Click the file selector dropdown
Choose one or more CSV or JSON files from your data folder
Multiple files can be selected for complex transformations
Variable Name Assignment: Each selected file needs a unique variable name that you'll use in your transformation code:
Default names are automatically assigned (file1, file2, etc.)
You can customize these names to be more meaningful
Variable names must be alphanumeric (letters and numbers only)
Names must be unique across all selected files
Example Setup:
customers.csv → Variable name: "customers"
orders.csv → Variable name: "orders"
products.csv → Variable name: "products"
If your CSV files use a delimiter other than comma:
Enter your custom delimiter in the delimiter field
Common alternatives: semicolon (;), pipe (|), tab
Default is comma (,) if left empty
You have two options:
Describe Your Transformation: In the AI prompt field, describe what you want to accomplish in plain English
AI Generates Code: Click the "Generate" button and the AI will create the transformation code for you
Review and Accept:
Preview the generated code in a modal
Review to ensure it meets your requirements
Click "Replace Code" to use the generated code
AI Prompt Examples:
Single Output File:
"Add a row number to each record"
"Filter records where status is active"
"Calculate total amount for each customer"
"Combine first name and last name into full name"
Multiple Output Files:
"Split data into active and inactive customers in separate files"
"Create three outputs: orders by region (North, South, West)"
"Generate a processed data file and a summary statistics file"
"Separate records by year and create a file for each year"
Write your transformation code directly in the code editor:
Use the provided code editor with syntax highlighting
Reference your input files by their variable names
Return either a single array or an object of arrays
Before saving, always test your transformation:
Click the Test button
The system loads sample data from your selected files (first 50 rows)
Executes your transformation code
Displays results in an interactive table
Test Results Display:
Single Output:
Shows total record count
Displays data in a sortable table
Preview all columns and values
Multiple Outputs:
Shows number of output files created
Tabs for each output file
Record count for each file
Individual tables for each output
After successful testing, click Next
Enter a Name for your transformation (alphanumeric only)
Enter a Description to explain what the transformation does
Click Save
Your transformation is now saved and ready to use in your workflows!
When you want one processed output file:
Your code returns a single array of objects
Creates one CSV file with your transformed data
The output file uses your specified name or defaults to the original filename
When to Use:
Simple filtering or field modifications
Adding calculated columns
Deduplicating records
Basic data cleanup
When you need to create multiple files:
Your code returns an object where each property is an output file
Each property name becomes the output filename
Each property value must be an array of objects
Creates a ZIP file containing all outputs
When to Use:
Splitting data by category, region, or status
Creating separate files for different time periods
Generating data file + summary/report file
Distributing data to different departments
Output File Naming:
Use descriptive property names in your code
Names are automatically sanitized for file system compatibility
You can configure custom output names in the workflow configuration
Default format: originalname_outputkey.csv
Add a Custom Transformation task to your workflow
Select your saved transformation from the dropdown
Choose the input file for processing
Configure output file name
Run your workflow
Be Specific:
❌ "Transform my data"
✅ "Filter records where amount is greater than 1000 and add a priority flag"
Mention Multiple Outputs Explicitly:
❌ "Split by region"
✅ "Create separate output files for each region (North, South, East, West)"
Include Business Logic:
❌ "Process the data"
✅ "Calculate days since last order and flag customers inactive for more than 90 days
The enhanced Custom Transformation feature combines the power of AI-assisted development with flexible multi-file processing capabilities. Whether you need simple data filtering or complex multi-output transformations, the intuitive interface and AI assistance make it accessible while maintaining the flexibility for advanced use cases.