WebRTC extension for Chrome

We provide Chrome extension for whitelabel WebRTC applications, which enables SIP URIs on any site to be opened with the WebRTC.

Extension can crawl text on any site and look for URIs fitting your chosen rules (e.g. Numbers with 6-9 digits). Links starting with sip: or your specific scheme will also be opened in WebRTC You can specify sites on which the extension should work.

URIs in text are wrapped in links, which by default show (on hover) extension icon and tooltip Open in WebRTC under it. Clicking on such links opens WebRTC and initiates voice call. Links on the page with correct format in their href attribute will send appropriate dialAction.


You can specify following settings in the Cloudsoftphone portal:

  • In the Chrome WebRTC extension section of Whitelabel options:
Extension name (webrtcext_name)

Name of the extension in the Chrome Web Store.


Extension version (webrtcext_version)

Version of the extension in the Chrome Web Store.


Extension description (webrtcext_description)

Description shown in the Chrome Web Store.


Rules for matching URIs (webrtcext_rules)

Use this to specify RegExp rules (without flags) for matching URIs, separated by semicolons. These rules will be used for searching URIs in text.

It is recommended to change this setting depending on what numbers does your app use.

(default: /[+d][- )(d]{2,14}d/ - matching any digit or + followed by any combination of digits / spaces / dashes, which has to be ended by digit. Matches numbers with total length 4-16.)

Whitelisted URLs (webrtcext_url_whitelist)

You can enter default URL whitelist here (URLs / RegExps separated by semicolons). It will be used for filtering sites to intercept links / crawl text on. Users will be able to modify this setting in their browsers, overriding default whitelist. Empty field will enable crawling text on all sites (except WebRTC itself). Please insert URLs without protocol (http/s://).

(default: None)

Open links in desktop application (webrtcext_open_in_desktop)

If this option is enabled, all links (and matching text wrapped in links) will be opened/called in desktop application, not in the browser tab.

(default: Disabled)

Enable searching text for URIs (webrtcext_text_crawl)

With this checkbox you can disable crawling text searching for the rules above.

(default: Enabled)

  • In the URI schemes section of Whitelabel options:
Call URI scheme (call_uri_scheme)

Extension will by default look for sip scheme in links and opening them in the WebRTC. You can specify your custom scheme in this setting. (please see Call URI documentation)

(default: None - extension will look for sip scheme.)

  • In the Theme editor:

You can see how will wrapped numbers and sip links look in the WebRTC theme, under Extension preview. You can also modify styles (or insert your own) in the properties on the left when you expand the Extension preview menu option. The live preview with number in the dummy paragraph will be automatically updated, so you can see the effect of your changes.

Wrapper / general styles

If you are not familiar with CSS, you can choose one of the prepared templates for displaying conditions of tooltip and icon.

If you understand the CSS language well, you can insert all styles for wrapper tooltip and icon here. Wrapped numbers and sip links will have class webrtc-wrapper, tooltip text webrtc-under-text and icon image webrtc-image. These styles will be loaded last, so you can overwrite all others properties here. You still need to upload your icon for the extension and specify tooltip text.

Link color
Here you can choose color for highlighting the wrapped numbers and sip links.
Icon for extension and tooltip
Please provide your own icon for the extension. It will be used for user menu in the browser and the icon displayed with the tooltip. It should have resolution of 128x128.
Icon styles
You can select on which side of the number should the icon appear. You can also tweak its positioning by modifying the pixel (px) values.
Tooltip text content
Please insert text for the tooltip.
Tooltip styles
Styles for the tooltip. You can tweak positioning and sizing of the tooltip by modifying the pixel (px) values.
Tooltip background color
Here you can choose color for the background of the tooltip.

Local installation and testing

You can test the extension locally. Open in your Chrome URL chrome://extensions, enable Developer mode, and under Load unpacked extension... choose the folder where you unpacked the zip file downloaded from CloudSoftphone portal.

Publishing in Chrome Web Store

Log in under your Google developer account in the https://chrome.google.com/webstore/developer/dashboard, add new item and upload the extension zip file.

Then you can upload the icon (128x128) and screenshots for the Web Store, write detailed description, choose language and payment options.

For testing the extension before distribution to users choose visibility private. Don’t forget to specify your testers’ email addresses in your dashboard. Then they can view and install the extension when you send them the link to the published extension. It might be then necessary to unpublish the extension and then re-publish it with public visibility for distribution.


You can distribute the extension without using the Chrome Web Store, but then you need to sign it according to this guide.

Updating via Chrome Web Store

Updating is done with uploading new .zip archive. Users do not need to re-install extension, Chrome will periodically (at least daily) check updates for its extensions and update them on browser restart. Extension will be updated after some time even when users don’t restart their browser, but they might need to reload pages affected by extension.