How can I format international phone numbers in n8n with a CDN-hosted JavaScript library?

Below is one recommended approach when you want to format phone numbers inside an n8n workflow:

1. Instead of trying to load the JS library via a CDN at runtime (which isn’t directly supported in the Code or Function node), install the library as a dependency in your n8n instance. For example, if you choose the simpler libphonenumber‑js library, install it (e.g. via npm):

BASHCopied
npm install libphonenumber-js

2. In your workflow, use a Code node (or Function node) to require and use the library. Pass your two parameters (for instance, the unformatted phone number and the country code) through node inputs (accessible on the $json property). For example:

JAVASCRIPTCopied
// Require the installed package
const libphonenumber = require('libphonenumber-js');

// Retrieve phone number and country code from the input JSON.
// You could set these values in a previous node or via expressions.
const phoneStr = $json.phoneNumber;  // e.g. "+14155552671"
const country = $json.country;       // e.g. "US"

const phoneNumber = libphonenumber.parsePhoneNumberFromString(phoneStr, country);

// Check that parsing was successful
if (!phoneNumber) {
  throw new Error('Invalid phone number input.');
}

// Format the phone number internationally
const formatted = phoneNumber.formatInternational();

// Return the formatted value
return [{ json: { formattedPhone: formatted } }];

3. Make sure the node that calls this Code node passes the correct parameters (the phone number and country code) via its JSON structure.

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Why Not Use a CDN in n8n?

n8n’s Code (or Function) node executes in a Node.js environment. In this environment, external libraries are imported via require (or ES modules) which requires the package to be installed on the system—loading libraries via a CDN (which is common in browser environments) is not available.

By installing the npm package, you ensure that your Code node has access to all the needed methods for parsing and formatting phone numbers.

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With this setup, your workflow is able to “clean up” or format phone numbers by simply passing the parameters into the Code node which then returns the formatted result.