withoneai CustomJS through One
CustomJS is an automation platform that provides JavaScript execution, PDF generation, screenshots, forms, static hosting, web scraping, and email-to-webhook tools through Make.com, n8n, and HTTP APIs, allowing teams to add custom logic and backend capabilities to no-code and AI workflows.
One exposes CustomJS through four MCP tools. The table below carries real action ids from One's knowledge base, so for a common operation you can skip search and go straight to reading the action's parameters.
How to run an action
- Find the action in the table below, or call
search_one_platform_actionswith platformcustom-jsif it is not listed. - Call
get_one_action_knowledgewith the action id. Do this every time, including for actions in this table. The table gives you the id, not the parameters. - Call
execute_one_actionwith parameters copied from that knowledge.
Never guess a parameter name, a body field, or an enum value. The knowledge has the real schema, and a guessed field is either a 400 or a silent write of the wrong thing.
Before you start
Call list_one_integrations once and confirm CustomJS is connected. If it is missing, the user has not connected it: say so and point them at https://app.withone.ai rather than reaching for raw HTTP.
Each connection carries an access field. If it reports {"policy": "methods", "methods": ["GET"]} the agent is read-only here, so plan a read-only answer instead of attempting a write that will be refused.
Before a write
Creates, updates, deletes and sends land on a real CustomJS account and cannot be recalled. State the action and the specific target in one line before the first write in a task, and let the user stop you. Reads need no confirmation.
Actions
HtmlToPdf
| Action | Method | Path | Action id |
|---|---|---|---|
| HTML to PDF | POST | /html2pdf |
conn_mod_def::GMa2rhUxtCA::Wr-gQASvQHayBM4mtt5UEw |
| Test Connection | POST | /html2pdf |
conn_mod_def::GMa0rTyROug::z4_htVW6S7-uhd--tr2c-A |
| Action | Method | Path | Action id |
|---|---|---|---|
| Compress PDF | POST | /{{functionId}} |
conn_mod_def::GMa2rhfKujg::R1lqOcDpSEWkR2DVrgYSUg |
CustomJsFunction
| Action | Method | Path | Action id |
|---|---|---|---|
| PDF to PNG Using a CustomJS Function | POST | /{{functionId}} |
conn_mod_def::GMa2riyPbHA::NYk87HY8TsSwSbK_XePkeQ |
PdfPages
| Action | Method | Path | Action id |
|---|---|---|---|
| Extract Pages from PDF Using CustomJS | POST | /{{functionId}} |
conn_mod_def::GMa2ri0Q1Vg::lys_jLnSR-Wd4T7Hvuc5VA |
Pdfs
| Action | Method | Path | Action id |
|---|---|---|---|
| Merge PDFs | POST | /{{functionId}} |
conn_mod_def::GMa2rjIteRA::7dtrkWkaQAm3C8LCBEy4iA |
Pages
| Action | Method | Path | Action id |
|---|---|---|---|
| Create an HTML Page | POST | /pages/page/upload-html |
conn_mod_def::GMa2rpj_zLA::pJpB2GDCQv6oCCs7x-Tjrw |
InvoiceGenerator
| Action | Method | Path | Action id |
|---|---|---|---|
| Generate an Invoice PDF Using CustomJS Invoice Generator API | POST | /invoice-generator-api |
conn_mod_def::GMa2rqcqmaA::n0PXQAJWQi-ae7OO4ck49Q |
PdfToText
| Action | Method | Path | Action id |
|---|---|---|---|
| PDF to Text Using CustomJS | POST | /{{functionId}} |
conn_mod_def::GMa2rsqfgSA::TDzQ6gR0QziqCXvPocLYrA |
CustomJsExecution
| Action | Method | Path | Action id |
|---|---|---|---|
| Run JavaScript Using CustomJS | POST | /{{scriptId}} |
conn_mod_def::GMa2rupk3cA::fTwpdysSSaOpFD8Nxojzrg |
When a call fails
The error comes from CustomJS, not from One. A 400 or 422 means your parameters do not match the schema, so re-read the knowledge and fix the field. A 401 or 403 means the connection needs re-authorizing, which no retry will fix. A 404 means the id is not on this account. A 429 means slow down. Never retry a write more than once: the first attempt may have landed.
Full catalog: https://www.withone.ai/knowledge/custom-js
Integration knowledge by One (withone.ai), licensed under One-Knowledge-1.0. Attribution must be preserved in derivative works.