CustomJS

About CustomJS

CustomJS is an API platform for executing custom logic within no-code and AI-powered workflows. It provides JavaScript execution with full Node.js and NPM support, HTML-to-PDF generation, webpage screenshot capture, static hosting for executable and AI-generated HTML pages, and a web scraper API for extracting structured data from websites. The service also includes a drag-and-drop form builder, a headless forms backend, a mail hook that forwards incoming emails to a webhook, and an MCP server that exposes its tools to AI agents.

The platform is designed to integrate with tools such as Make.com and n8n, letting users deploy custom code logic directly within those automation platforms or call the functionality via API. Typical use cases described include generating invoice PDFs from Airtable data, composing emails with ChatGPT-generated content, building HTML forms with success pages, and exporting Airtable data as JSON with resolved linked tables.

CustomJS offers a free tier with 600 API requests per month. The company behind the product, TechnologyCircle GmbH, is based in Hamburg, Germany.

Key features

• Run Node.js JavaScript with full NPM support via API
• Convert HTML to PDF documents
• Capture screenshots of any web page
• Host static, AI-generated HTML pages and forms
• Drag-and-drop form builder plus headless forms backend
• Forward incoming emails to a webhook (Mail Hook)

Frequently asked questions