Install the Snippet

Install the Edesy call tracking script - one async tag with your pool key, allowed domains, what it swaps (data-edesy-ct, tel links, text), consent mode, the EdesyCT JavaScript API and what it stores.

3 min read

The call tracking snippet is one script tag. It loads from Edesy, asks for a tracking number for the visitor, and swaps your website's number for it. It is about 3 KB gzipped and has no dependencies.

The tag#

Paste this into the <head> of every page. Copy the exact tag from your pool's Install tab; the data-key is your pool's public key.

<script async src="https://voice-api.edesy.in/v1/public/ct/edesy-ct.js" data-key="ctk_XXXXXXXXXXXXXXXXXXXXXXXX"></script>
Attribute Meaning
data-key Pool public key, starting ctk_. Required. It is not a secret
data-consent="required" Do nothing until window.EdesyCT.consent() is called

The script works with tag managers and single-page apps. Content added later (route changes, modals) is swapped too.

Allowed domains#

The pool only answers requests from the domains you listed, checked against the browser's Origin or Referer.

  • example.com matches example.com and www.example.com.
  • *.example.com matches example.com and every subdomain.
  • Matching is on whole labels, so example.com never matches evilexample.com.
  • A pool can list up to 50 domains.

If a page is on a domain that is not listed, the script leaves your normal number in place.

What gets swapped#

The script replaces each of the pool's website numbers (up to 10) with the visitor's tracking number:

  1. Elements marked data-edesy-ct, the most reliable option. The text becomes the formatted number, and an <a> also gets href="tel:+91...". 
    <a data-edesy-ct href="tel:+912240001234">+91 22 4000 1234</a>
  2. tel: links whose number matches one of your website numbers, in any format.
  3. Text containing one of your numbers, written as +91 22 4000 1234, 022-4000-1234, (022) 40001234, 02240001234 and similar. Your site's separators are kept.

Scripts, styles, form fields and editable regions are never touched. If a number is split across elements or written in an unusual way, mark it with data-edesy-ct.

When the page keeps its own number#

The script never shows a broken or empty number. Your normal number stays when:

  • the script cannot load, or storage is blocked
  • the pool is paused, or the domain is not allowed
  • every number is in use and the pool shows the normal number
  • the pool is set to paid traffic only and the visit has no click ID or paid utm_medium
  • the visitor looks like a bot (crawlers, ad reviewers, uptime monitors, scripts)

If you need consent before setting storage, add data-consent="required" and call window.EdesyCT.consent() from your consent banner when the visitor agrees.

JavaScript API#

window.EdesyCT.consent();          // start, when data-consent="required"
window.EdesyCT.getNumber();        // { number: "+912240009999", display: "+91 22 4000 9999" } or null
await window.EdesyCT.ready;        // resolves to the same, or null; never rejects
document.addEventListener('edesy-ct:ready', (e) => render(e.detail.display));

edesy-ct:ready fires after each successful swap, including when the number changes after a lost lease.

What the script stores#

Key Where Content
edesy_ct_vid localStorage Visitor ID, 90 days rolling
edesy_ct_ft localStorage First touch: campaign parameters, landing URL, time, 90 days
edesy_ct_lt localStorage Last touch, reused for 30 minutes on pages without parameters
edesy_ct_cfg sessionStorage Pool configuration, 5 minutes
edesy_ct_s sessionStorage Current session and number, until the lease ends

Landing pages and referrers are stored with only the attribution parameters (utm_*, gclid, gbraid, wbraid, fbclid, msclkid); other query parameters, such as form fields, are dropped. Visitor IP addresses are kept only as a network prefix.

Keeping the number while the page is open#

While the tab is visible the script renews the visitor's lease every 60 seconds, so a long visit keeps the same number. A returning visitor whose lease is still live gets the same number back. See Number Pools.

FAQ#

Does the script slow my site down? It loads with async, is about 3 KB gzipped and runs after the page. If it fails, nothing on the page changes.

Can I install it with Google Tag Manager? Yes, as a custom HTML tag on all pages. Make sure the page's domain is in the pool's allowed domains.

Do I need to change my website's markup? Usually not: tel: links and written numbers are found automatically. Add data-edesy-ct only where a number is split or unusually formatted.

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