We are excited to announce the deployment of a new version of the UTU Trust Token (UTT), the heart of the UTU Protocol, on the Polygon Mumbai testnet and mainnet and NEAR Aurora.

This release marks a significant milestone in the $UTU/UTT Economic Model, providing easier development and expanding access to UTU Trust Token (UTT), UTU Coin ($UTU), and the UTU Trust API/SDK to a wider range of users and decentralized applications (dapps). It is also a big first step towards our multi-chain future.

New Features

Earn money for building trust online with $UTU Rewards!

Buildr Note: Your d(apps) can now offer your users an additional benefit (in the form of UTT and $UTU Rewards) when their positive feedback about your product helps future users discover and love you too!

The new version implements UTU Coin ($UTU) rewards for successful endorsement, as a function of the rewarded amount of UTT for the same. The rewarded $UTU will be claimable for users who connect to social networks or ID schemes which have been whitelisted for this purpose. Currently, there are no such whitelisted services, but we will soon post bounties for implementation of some that could be candidates, subject to contract governance.

The contract is currently owned — and thus governed — by UTU’s UTT deployer wallet, but we will soon transfer this to a multi-signature wallet.

Going Multi-chain: Access UTU on NEAR Aurora!

UTT now also supports being called via proxy from NEAR Aurora, and in the future possibly other EVM chains. For this purpose, we’ve deployed a UTTProxy contract on Aurora, which forwards endorsement and $UTU reward claims to the main UTT contract on Polygon.

This was also deployed both on testnets and mainnets, so you can try it out e.g. using the Aurora test net explorer. Currently, there are no client applications supporting Aurora yet, but this will change soon: we’re going to add support for Aurora to the UTU SDK and the browser extension, and of course we’re looking forward to apps on Aurora integrating UTU.

UTU Coin on NEAR Aurora

As part of our deployment of the UTTProxy on NEAR Aurora, and its capability to reward $UTU, we’ve also bridged $UTU to NEAR.

We recently saw dozens of devs building on UTU at the ETHSafari Hackathon, buidling 7 projects implementing UTU’s reputation and reviews mechanism in exciting ways like Elimu DAO, Trustify, and Web3 Guardian.

Smart Contract Upgradability to ease future improvements!

This new version is now also upgradable, so (most) upgrades in the future will not require a migration. A migration requires not only the transfer of the contract state from the old to the new version, but also client software which interacts with the contract directly, such as the UTU SDK and its integrating apps, to be updated to use the new version.

Migration from v1

The complete contract state has been migrated from the old to the new version, so the only thing that users need to do to keep using UTU is to upgrade their browser extension and other integrating apps to the latest versions.

Those who would like to verify that the migration was done correctly can review the contract implementation code and migration transactions, the first 133 transactions from contract creation up to the setDataMigrationCompleted call.

New UTT & $UTU Contract Adresses

Main Nets

Test Nets

Technical Bits


With all these added functionalities, the contract code became rather large and unwieldy. To better separate responsibility, we’ve split the contract up into several abstract base contracts, one for each concern. We hope that this improves understanding both for our own team and external devs and users.

We’ve also extracted two interfaces which encapsulate the main public APIs for apps interacting with UTT, including methods and relevant events:


The contract always had a complete set of unit and integration tests, and this is still true. The tests have been amended in the new version to cover all added features, including calls via UTTProxy, upgrades and migration.


We already have the next UTT upgrades in the pipeline, which will include the implementations of

  • removal of UTT stake from an endorsement and
  • disapprovals and their accompanying penalties according to the UTU white paper.

Finally, we’re going to amend the UTU developer documentation with information about UTT.


The new version of the UTU Trust Token (UTT) brings several exciting features and improvements. The implementation of UTU Coin ($UTU) rewards for successful endorsement provides users with additional incentives and promotes engagement. UTU’s multi-chain support is starting with NEAR Aurora, with UTT to be called via proxy from NEAR Aurora with other EVM chains coming in the near future, expanding UTU’s accessibility and potential integrations.

The contract’s upgradability ensures that future improvements can be easily implemented without requiring a migration, streamlining the upgrade process for UTU Devs – meaning faster, more frequent upgrades. The successful migration from the previous version to the new one ensures a seamless transition, and devs can verify the migration through the provided contract implementation code and migration transactions.

For web3 users, these releases open up new opportunities to engage with UTU Trust Token (UTT) and UTU Coin ($UTU) across different chains. The wider range of users and d(apps) can now benefit from the UTU Trust API/SDK, building trust in web3 ecosystems. Additionally, the bridging of $UTU to NEAR Aurora expands its reach and potential use cases within the NEAR ecosystem.

These developments demonstrate UTU’s commitment to advancing the UTU Protocol and building trust in decentralized systems. With the continuous improvements and upcoming upgrades, such as the removal of UTT stake from endorsements and the implementation of disapprovals, UTU is poised to deliver even more value and enhance the reputation and reviews mechanism in web3.

Discover how to leverage UTT’s functionalities and supercharge your dapps by diving into the UTU developer documentation today!