# Customjs AI integration on Definable

> CustomJS is a code-first automation platform that enables seamless integration of custom JavaScript logic into various systems and technologies, allowing users to extend applications by writing functions for tasks like sending emails, generating PDFs, or updating CRM data fields.

## What this connects

CustomJS is a code-first automation platform that enables seamless integration of custom JavaScript logic into various systems and technologies, allowing users to extend applications by writing functions for tasks like sending emails, generating PDFs, or updating CRM data fields.

Vendor: https://www.customjs.space/

## Tools available

**5** tools available. First 5:

- `CUSTOMJS_AUTHENTICATE_API_KEY` — Authenticate CustomJS API Key — Authenticate and validate a CustomJS API key. Returns workspace details, request limits, and decoded JWT token information including user email. Use this to verify an API key is valid before making other CustomJS API calls.
- `CUSTOMJS_CONVERT_HTML_TO_PDF` — Convert HTML to PDF — Convert HTML content to a PDF document. Use this tool to generate PDF files from raw HTML markup. Supports: - Complete HTML documents or fragments - Inline CSS styling (colors, fonts, tables, borders, backgrounds) - Unicode characters and special symbols - Multi-page documents Returns raw PDF bytes suitable for file storage or download.
- `CUSTOMJS_CONVERT_HTML_TO_PNG` — Convert HTML to PNG — Tool to convert HTML string to PNG image. Use when you need a PNG from HTML after preparing your markup.
- `CUSTOMJS_MERGE_PDFS` — Merge multiple PDFs into one — Merge multiple PDF files from URLs into a single PDF document. Use this tool when you need to combine two or more PDF documents into one. The PDFs are merged in the order provided. All input URLs must be publicly accessible. Returns a downloadable merged PDF file.
- `CUSTOMJS_RUN_PUPPETEER_SCRIPT` — Run Puppeteer Script — Execute a Puppeteer script in a headless browser and capture a screenshot. Use this tool for browser automation tasks such as navigating to URLs, interacting with page elements, extracting data, or capturing visual snapshots of web pages. The script runs in a sandboxed Puppeteer environment with access to a 'page' object.

## Auth

Auth schemes: `API_KEY`.

## How agents use Customjs

Inside a Definable workflow, Customjs is one of the tools the **Distributor specialist** can call. Example coordination patterns:

- **Researcher → Customjs** — the Researcher (GPT-5.5) pulls context from Customjs (records, threads, documents), synthesises findings, and briefs the rest of the team.
- **Writer → Distributor → Customjs** — the Writer (Claude Opus 4.7) drafts copy in brand voice, the Verifier passes it, then the Distributor writes the result into Customjs (create record, post message, draft email).
- **Designer / Engineer → Distributor → Customjs** — the Designer ships an asset or the Engineer ships a code change, the Distributor delivers it via Customjs (attach file, open PR comment, post status).

The Verifier checks every Customjs call. On rate limit, schema drift, or auth refresh it self-heals and retries — the workflow completes without manual intervention.

## Categories

- developer tools — https://definable.ai/apps/category/developer-tools/

## Related

- HTML page: https://definable.ai/apps/customjs/
- Same category (developer tools): https://definable.ai/apps/category/developer-tools/
- All integrations: https://definable.ai/apps/
- Workflow (multi-agent loop): https://definable.ai/workflow/
- Apps llms.txt index: https://definable.ai/llms-apps.txt