Changelog

Keep track of every change on the Cello platform

July 30, 2025

Referrer engagement series - Micro-loop announcements

Lightweight micro-loops improve the engagement with interested referrers. The announcements re-engage interested users who haven’t yet shared, created views, or earned rewards.

Your referrers receive contextual reminders tied to their behaviours within the referral widget or tied to the behavior of invited new users.

Referrer engagement series - AI-powered sharing suggestions (experimental)

We’re testing a new way to help referrers personalize their invite messages using AI.

When sharing, users see smart suggestions based on your products context and key value propositions. AI helps to craft a compelling message in seconds.

This is experimental and only rolled out to a few customers for now.

Want to try it? We’re looking for partners to explore how AI might lift sharing performance.

July 28, 2025

We’ve shipped a collection of updates focused on flexibility, reliability, and a smoother user experience.

New Languages Added

We have expanded our language support by adding 🇩🇰 Danish (DA) and 🇸🇰 Slovak (SK). This makes it possible to provide fully integrated referral experience for more and more users.

Improved Referrer Email Deliverability

Referrer emails have been optimized to prevent them from landing in spam folders, ensuring that your users receive referral-related communications without interruption.

Chargebee Webhook Now Supports Custom Fields

Our Chargebee webhook now fully supports custom fields (CF), providing more flexibility in sending Cello signup and transaction events. Learn more about custom fields in the Chargebee documentation.

Enhanced Mobile SDK Referral Component

The referral component for the mobile SDK has been significantly improved for a smoother user experience. Users now have:

• An always accessible Rewards page.
• Notifications about their first link view and first reward, helping them stay informed and engaged.

Revenue Growth Analysis

Cello now provides detailed revenue growth analysis on your Purchases page. These charts help you understand exactly how your recurring revenue is growing and where opportunities or risks may exist:

• New ARR - Revenue from first-time customers
• Expansion ARR - Revenue growth from upgrades and upsells
• Contraction ARR - Revenue lost from downgrades
• Lost ARR - Revenue lost from churn
• Net ARR Growth - Overall monthly revenue change

Each component can be individually enabled or disabled using the chart menu in the upper right corner.

April 09, 2025

Cello now detects and recovers missed attributions to avoid gaps and strengthen the attribution flow. These recovered referrals are clearly marked on the New Signup and Purchase pages within the Cello Portal.

January 30, 2025

Multi-campaign support in the Cello portal

The Cello portal now shows all active campaigns for your product. You can add new partner campaigns and change existing ones.

December 18, 2024

Announcement improvements

This release we have added a few improvements for announcements:

Announcements with CTA

You can now add a button to announcements which provide a clear call-to-action for referrers and can increase activation rate.

Cello.js API to trigger announcement

Now you can trigger an announcement using a client-side JS method. Example below will trigger the default welcome announcement:

window.Cello("showAnnouncement", { "type": "welcome-announcement-1" } );

November 22, 2024

Notifications preview

The Notifications setup in Portal has been updated! You can now preview all notifications sent during the referrer’s journey. Easily review alerts, announcements, and emails to see their design, copy and preview them in different language.

November 5, 2024

Cello for mobile

We have released new versions of our mobile SDK’s for iOS, Android and ReactNative. This version contains:

• 🤳 Full featured Cello Widget that allows users to track their views and rewards, and enter payment details to claim their rewards
• 🐞 General bugfixes

September 15, 2024

Onboarding guide update

Onboarding guide in the Cello Portal is now your one-stop destination for everything you need for a seamless onboarding experience, including a clear view of your progress with completed and pending tasks.

August 20, 2024

Partner management

You can now add partners to your Partner Program directly in Cello Portal.

July 16, 2024

Our Attribution library has gotten a few exciting improvements 🎉

Async methods and race condition handling

Attribution library methods are asynchronous and return a promise. This guarantees that developer does not have to implement their own blocking mechanism and the promise resolves once the action or data is available. Developer can use either the straight up cookie handling with .then methods or with async/await .

In addition to that, to avoid race condition of our script loading and your application trying to communicate to it, you should add the following javascript code before any of the calls to the library.

window.CelloAttribution=window.CelloAttribution||async function(t,...o){if("getReferral"===t)throw new Error("getReferral is not supported in this context. Use getUcc instead.");let e,n;const i=new Promise((t,o)=>(e=t,n=o));return(window.CelloAttributionCmd=window.CelloAttributionCmd||[]).push({command:t,args:o,resolve:e,reject:n}),i};

New JS Methods for custom cookie handling

We have added 2 new methods for custom cookie handling, to dynamically inform it when a visitor has consented to cookie storage. This method offers full control over the timing of cookie storage, allowing you to align it with your user consent process.

allowCookies

To allow the storage of the referral code cookie:

window.CelloAttribution('allowCookies');

deleteCookies

To halt the storage of the referral code cookie and clear it:

window.CelloAttribution('deleteCookies');

June 12, 2023

🐞 Bugfixes and improvements

May 6, 2024

Improved payment details screen

We’ve made it easier to update your payment details in the Referral component. Now, there’s no need to re-enter all info. Users can change what’s needed, and they’re set!

We’ve also enhanced privacy and security around users’ personal data. Sensitive info like address isn’t visible anymore once it’s entered — users can only update it. This change makes it tougher for the bad guys to get their hands on users details.

Easier token management

By default, there will be no need to keep updating the Referral Component user authentication token every 24h. Now, tokens are issued to be long-lived and won’t expire unless you want them to. Prefer your tokens with an expiry date? No problem. Just reach out to our Customer Support to enable token expiration.

May 1, 2024

Self-referral signups are now automatically excluded from trends and can be reviewed in the Cello Portal. From New User Signups, you will find these marked as Excluded in the list and no longer included in the overall aggregate trends.

April 30, 2024

Cello SDK for React Native is now available. Now you can add sharing into your Android and iOS apps built with React Native. With a plug-n-play mobile sharing component, your users can easily share their invite link with their friends and network using mobile sharing options convenient for them. Find out more here 👉

April 23, 2024

Cello SDK for Android is now available. Now you can add sharing into your Android app. With a plug-n-play mobile sharing component, your users can easily share their invite link with their friends and network using mobile sharing options convenient for them. Find out more here 👉

April 10, 2024

We have improved Referral Component boot() command to return a promise that is resolved once the whole initialization process is finished or rejected if the boot command failed. It is optional to use if you want to wait in your code until boot() command has finished.

window.cello = window.cello || { cmd: [] };

window.cello.cmd.push(async function (cello) {
  try {
    await cello.boot({
      productId: 'CELLO_PRODUCT_ID',
      token: 'REPLACE_ME',
      language: "en"
    });
    // call other Cello commands, if necessary
  } catch (error) {
    console.error("Failed to boot cello:", error);
    // Handle the error appropriately
  }
});

April 9, 2024

We have rolled out back-end improvements to data processing and data aggregation in the Cello Portal, especially around how unique view counts are aggregated. While these changes are mostly transparent to users, there may be minor differences in daily or monthly counts across metrics as a result of these improvements and resulting rate calculations.

February 15, 2024

Cello SDK for iOS is now available. Now you can add sharing into your iOS app. With a plug-n-play mobile sharing component, your users can easily share their invite link with their friends and network using mobile sharing options convenient for them. Find out more here 👉

December 19, 2023

🤝 We are excited to announce our Partner add-on, which allows you to set up and manage your own partner program. Cello now unifies both use cases of user referrals and partner programs in one platform.

Additional partner features are offered as an add-on to the core Cello platform (no additional technical effort needed). If your are interested in this functionality or you already have a program that you would like to transfer to Cello, feel free to contact our support team to guide you through the setup.

November 6, 2023

🐞 Bugfixes and improvements

October 19, 2023

💌 Keep Your Users Engage: Welcome Email Notifications!

Referral programs thrive on timely engagement. Knowing instantly when there’s activity tied to a referrals means your users can celebrate successes and continue to share more effectively. Whether it’s their first successful share, a brand-new signup or unlocking a new reward, email notifications ensure they never miss a beat in the referral journey.

To enable Email notifications, make sure you are passing user details in the Referral component initialization.

<script>
      window.cello = window.cello || { cmd: [] };

      window.cello.cmd.push(function (cello) {
        cello.boot({
          productId: 'CELLO_PRODUCT_ID',
          token: 'REPLACE_ME',
          hideDefaultLauncher: false,
          productUserDetails: {
            firstName:'Bob', // add your users name to personalize email
            lastName:'Bobsky',
            fullName:'Bob B Bobsky',
            email: '[e-mail]' // add your users' email to enable Email notifications
        }
        });
      });
</script>

September 30, 2023

🐞 Bugfixes and improvements

September 14, 2023

We have added a way to open Referral component on a specific tab/page either using a new JS method page or a deep-linking with a URL parameter. Now you can direct your users to a specific area of the sharing experience based on the call to action in either your communication or in-product triggers.

Example of how to use JS method to open the component on Rewards tab:

window.Cello("open","rewards")

Example of how to use deep-linking to open the component on Rewards tab:

https://your-product.com?cello-open=rewards

August 31, 2023

You can now find out which one of your users has referred a new user. Using Cello API /referral-codes simply pass the unique campaign code the new user signed up with and get back the user’s productUserId the ucc belongs to.

{
    "code": "UIPIWa2Hnnr",
    "productUserId":"12345678"
    "valid": true
}

200 OK

August 16, 2023

Personalization for new user message

Now, you can incorporate the referrer’s name into the message displayed for new users on your signup page. When visitors use the Cello invite link, they’ll be greeted with a personalized banner, adding an element of social proof to the onboarding process.

QR Code has moved

We’ve enhanced our user experience! Mobile sharing option, i.e. QR code scanning, is now conveniently located on a dedicated page. Access them with the QR code button next to other sharing choices. This refinement ensures the main page spotlights your program’s offer while keeping all sharing functionalities organized and within easy reach.

July 18, 2023

🇫🇷 Bonjour! 🇳🇱 Hallo! 🇪🇸 ¡Hola! 🇮🇹 Ciao!

We now support 4 new languages: French, Dutch, Spanish and Italian. 🇫🇷 Bonjour! 🇳🇱 Hallo! 🇪🇸 ¡Hola! 🇮🇹 Ciao!

New referral component JS method to unlock Aha moments

Cello referral component has just gotten a new JS method getActiveUcc(). This allows you to display referrers link anywhere the user flow, specifically during moments of delights when sharing is most relevant and contextual for your user. Find out more about in our contextual sharing guide.

July 5, 2023

We’re pleased to announce the release of a new endpoint in the Cello API, /active-link, to facilitate the retrieval of active link and campaign code associated with your user (productUserId). This enhancement serves as a powerful tool, enabling a broad range of contextual sharing use cases, and potentially broadening the scope and impact of your referral program.

For insights into how best to leverage this addition and explore various use cases, please refer to our Contextual sharing guide.

To understand the specifics of the new /active-link endpoint, you can visit the Cello API Reference. This is a significant step towards enriching your user experience, and we look forward to seeing the innovative ways you’ll make use of this feature.

June 29, 2023

We are excited to announce that our latest Cello component design, which was introduced in May, is showing promising results in sharing metrics. As a result, we’ve decided to phase out the previous version of the component and update our existing CDN URL (https://assets.cello.so/app/latest/cello.js) to direct to the newer version.

What Does This Mean For You?

No action is required on your part. The transition to the updated version of the component will occur seamlessly in your application. The new component is designed to operate flawlessly within your existing configuration, without the need for any adjustments.

Timeline of the Update

• Starting Monday, July 3, URLs for dev and stage accounts will direct to the updated version of the component. This allows you to preview and test the update, providing us with any feedback or necessary adjustments.
• From Monday, July 10, the current production URLs will redirect to the updated component version.

Key Update Note

The new component design introduces the functionality to update the token used for user authentication. We encourage you to review and adjust your logic to accommodate this new feature. Detailed information regarding this change can be found in our documentation.

May 23, 2023

• New Referral component design - UX with tabbed navigation, descriptive notifications and more accessible design. Switching to the new referral component requires minimal effort. Just switch the CDN URL in your code to https://assets.cello.so/app/v2/latest/cello.js . No other migration effort needed. The v1 Referral Component will remain functional and supported, but will not receive any new updates apart from critical security fixes.

• JWT token update - Simplify how you update JWT token for Cello Referral component with new method and events. Cello tokens are kept alive 24h. To allow users uninterrupted access to Cello throughout their session in your product, listen to onTokenExpiring event and pass in a new token using updateToken(token) method. For more details go to User authentication guide.

May 3, 2023

• We have made opening of the Cello referral component with a link super easy. Just add ?cello-open=true param to your the URL. Add a link to referral component to your email communication to help your users access the sharing directly from the email. For more details, go to Referral Component docs

https://your-product.com?cello-open=true

• We have added support for Norwegian language to the Referral Component. Now we support English, German and Norwegian.
• Announcements now have much more customization options. You can now change background color, add a dismiss button and an icon.

March 7, 2023

A handful of bug fixes and minor improvements

February 22, 2023

Improved attribution library - now referral code (UCC) cookie also works across subdomains.

February 15, 2023

Fixed cello.hide() method behaviour. Now Referral Component will also be closed automatically, when cello.hide() method is called

January 31, 2023

A handful of bug fixes and minor improvements

January 17, 2023

We have introduced new options to Cello.js API: onOpen() and onClose() - callbacks to allow you to hook into event when Cello Referral Component is opened or closed. More details in JavaScript Browser docs.

Please download & install the updated Chrome Extension if you want to simulate the referral experience.

December 21, 2022

• New Cello.js API to improve loading of Cello Referral Component - now all interactions with the cello API are being done in a queue of callbacks to guarantee the right order of commands for Cello Referral Component boot during page load. The old API is still functional, but will be deprecated eventually so we advice to switch to the new way. More information can be found on our JavaScript Browser docs page.
• Updated payment details screen - enhancements to support multiple countries and receiving reward payouts to a business account.

December 7, 2022

Bug fixes and minor improvements

November 28, 2022

Improved Referral Component (cello.js script) initialization and authentication flow

November 25, 2022

Fixed a notification bug that cause the notification badge to intermittently appear after page refresh

November 16, 2022

• Improved conversion funnel analytics and KPI reports
• A handful of bug fixes and minor improvements

October 26, 2022

In this release we are introducing short referral links and unique campaign codes or ucc.

Shorter links

Now referrer will be able to share a shorter, neater looking link which will also have the product name included in it.

The new structure of the links:

https://[product_name].cello.so/[ucc]

Example:

https://curlytics.cello.so/SgqXJPU3n0X

UCC or Unique Campaign Code

Referrers will now be identified by a unique campaign code or ucc, instead of the referrerId. ucc represents exactly what its name implies. It identifies who the referrer is, but also what the campaign that the referrer shared was. As campaign’s get updated, a ucc will also change, but the old links, that have already been share will keep working and point back to the correct campaign terms.

All the old long form links will keep working and referrerId’s issued will still be valid and can be used for attribution.

October 13, 2022

• Added Notifications for new sign up or demo events. Referrers will now be notified when someone they have referred has signed up for free trials or requested a demo for the product.

• Fixed a bug with notifications badge position on the Cello button.

October 5, 2022

• Added Named user whitelist for Referral component. Now when Piloting Cello Referral program, you can start with a small cohort of selected users, by providing a list of their UID’s (productUserId's) to Cello and only these users will have access to the Referral component until you are ready to rollout to your entire user base. Read more about Named user whitelist here.
• Added a configurable “How does it work” instruction screen. Now you can provide description of your referral program to your users from inside the Referral Component, so they know exactly what to expect.

• Added options for Referral Component position. Now the Cello button, used to launch the component, can be positioned anywhere on the left side of the screen

September 14, 2022

• Added motion animation for a smoother transition when opening and closing the Referral component and QR code for mobile sharing