USDC Now Available on Celo

We’re excited to announce that USDC is now available on Celo and accessible to developers and users – no bridging required. Circle Mint and its APIs now fully support USDC on Celo, making it easy to access USDC liquidity and benefit from Celo’s low-cost transactions that can settle in seconds.


About Celo

Celo is a mobile-first, EVM-compatible blockchain that’s built for the real world and designed for fast, low-cost payments worldwide. The Celo ecosystem has over 1,000 projects in more than 150 countries, who are committed to Celo’s mission of creating economic prosperity for all.


Why USDC on Celo

  • A global, mobile-first user base
  • An existing ecosystem of RWAs, including stablecoin use cases
  • A diverse network of fast-growing Apps & projects

USDC issued by Circle is native to Celo, joining the ecosystem’s pioneering stablecoin use cases, including remittances, savings, lending, aid disbursement, peer-to-peer (P2P), and cross-border payments.


Global Dollar Access  

Circle’s mission to raise global economic prosperity through the frictionless exchange of value closely aligns with the mission of Celo’s global ecosystem. USDC supports regions of the world that are facing inflation by enabling access to digital dollars for a trusted, stable store of value.


USDC issued by Circle


Powering new use cases

Exchanges, digital wallets, institutional traders, and developers can access USDC on Celo via Circle Mint and its APIs for a number of use cases:


  • Making low-cost payments and remittances globally that can settle in seconds
  • 24/7 trading, borrowing, and lending on apps like Uniswap
  • Enable users to hold savings in digital dollars without needing a traditional bank account


Governance Proposal: Pay Gas Fees with USDC

One of Celo’s key features includes paying for network gas fees (i.e. transaction costs) with stablecoins for a familiar and frictionless payments experience. Recently, cLabs started a discussion on the Celo Forum to discuss enabling users to pay gas with USDC, and a formal proposal is expected to be voted on soon. 


Get started today

Businesses can readily access on/off-ramps for converting fiat currency to USDC on Celo by applying for a Circle Mint account.

Developers can start integrating with USDC on Celo with our developer docs – USDC is an open-source, permissionless protocol that anyone can build on.

Circle is Discontinuing Support for USDC on the TRON Blockchain

Circle is discontinuing support for USDC on the TRON blockchain in a phased transition. Effective immediately we will no longer mint USDC on TRON. Circle will support Circle Mint customers’ transfer(s) of USDC to other blockchains through February 2025. As Circle only serves business and institutional customers, retail users and other non-Circle customers can move their USDC on TRON to an exchange or distributor where it can be transferred to another blockchain where USDC is supported. 


Options for USDC on TRON Users

Through February 2025, Circle Mint customers may transfer USDC to other blockchains, or redeem USDC on TRON for fiat currency directly with Circle.


Retail USDC holders and non-Circle customers may use the hundreds of global services available, including retail exchanges, brokerages and on/off-ramp providers, to transfer USDC between blockchains or redeem their USDC for fiat currency. 


As always, USDC remains redeemable 1:1 for US dollars.


Looking Forward

As part of our risk management framework, Circle continually assesses the suitability of all blockchains where USDC is supported. Our decision to discontinue support for USDC on TRON is the result of an enterprise-wide approach that involved the business organization, compliance and other functions across our company. This action aligns with our efforts to ensure that USDC remains trusted, transparent and safe – characteristics that make it the leading regulated digital dollar on the internet. 


Our commitment to growing USDC remains steadfast. We will continue to expand USDC’s reach to additional blockchains to deliver the widest access, broadest developer choice, and most secure user experience of any dollar stablecoin in the world.

The Importance of a Regulatory Regime for Dollar-Backed Payment Stablecoins

On February 15, Caroline HIll, Circle’s  Senior Director of Global Policy and Regulatory Strategy, testified before the House Financial Services Subcommittee on Digital Assets, Financial Technology, and Inclusion on ways to combat illicit finance activity in the blockchain space. 


Policymakers from across the political spectrum have increasingly focused on illicit finance and the intersection with unregulated virtual asset service providers to push for strengthening anti-money laundering and countering the financing of terrorism (AML/CFT) rules applying to crypto. Caroline’s expert testimony not only distinguishes Circle’s voice as a compliance leader but also reinforces the importance of a regulatory regime for dollar-backed payment stablecoins.


Coming at a pivotal time for the policy debate around illicit finance, and as stablecoin legislation negotiations continue to progress, key themes from Caroline’s  testimony included: 


  • Digital assets serve as an enhancement to the restrictive and fragmented payments systems, bringing nearly instant, 24/7 settlement to the everyday consumer. The U.S. government – through its policies and regulations – can do more to support these innovations and harness the power of blockchains. 
  • Circle has differentiated itself through a regulatory-first approach and has demonstrated a compliance track record that has exported stability, rule of law, and respect for AML/CFT standards to the broader digital assets market.
  • The US government should consider ways to strengthen the role of the US dollar in the future, including supporting US-led innovation and initiatives to make the dollar the base currency of digital assets. Regulated, USD-denominated payment stablecoins like USDC import robust compliance measures and the US rule-of-law to the digital asset space.
  • More broadly, supporting the development of digital identity tools and international standards around digital identity management would aid both the private sector and US government in the detection and reporting of illicit financial activity.


Caroline’s expert testimony drew from her deep professional experience at the U.S. Treasury Department – first as an OFAC sanctions investigator and then in international policy roles – where she saw firsthand the role and importance that compliant financial institutions, like Circle, play in detecting and disrupting illicit finance.  

A recording of the hearing and access to written testimony can be found here.

USDC Redemption Process Updated to Expand Liquidity Worldwide

Circle is proud to offer robust redemption capabilities and has introduced new Circle Mint redemption options to help us provide even more USDC liquidity across the globe. Circle Mint Customers now have the choice between Standard and Basic redemption for managing their USDC needs, however, all customers will automatically be enrolled in our Standard redemption offering. Customers who choose to switch to Basic may visit our Help Center to get started.


Standard redemptions are free for Circle Mint customers redeeming up to $15M USD a day, and every submitted redemption request will process in real time on Circle’s systems. Settlement time may vary based on the transaction method and banking rails involved. Redemption amounts above $15 million will incur a 0.1% fee. 


Upon request, Basic redemption is available to all Circle Mint customers as well, offering a fee-free redemption option, regardless of transaction volume, however, processing can take up to two business days. With this option, settlement times may also vary based upon the transaction method and banking rails involved. 


As always, USDC remains redeemable 1:1 for U.S. dollars.

Circle Contributes USDC to Support Scholarship for Emerging Market Regulators

Since Circle’s founding in 2013, we have supported initiatives that share our vision for a more open, accessible and well-regulated financial system for people across the globe. As part of this effort, Circle recently contributed $50,000 in USDC to support the Emerging Markets Scholarship program at the renowned Program on International Financial Systems (PIFS). 


PIFS’ mission is to enhance the role of regulation in building the global financial system. It was founded in 1986 as part of Harvard Law School and became independent in 2018. Today, PIFS collaborates with Harvard Law School Executive Education and organizations such as the International Organization of Securities Commissions (IOSCO) and the Gulf Cooperation Council (GCC) to deliver training programs for regulators. The programming addresses topics such as international development, banking supervision, financial technology, digital assets and sustainable finance.


Circle’s USDC contribution will help fund PIFS’ Emerging Markets Scholarship Program, which arranges training programs for financial regulators in developing economies across Africa, Eurasia and Latin America. In 2023, the program trained over 1,350 financial regulators from 119 agencies in 62 developed and emerging markets. Scholarship beneficiaries can include public officials and government employees at finance ministries or central banks, and capital market regulators in emerging markets, including: Brazil, India, Kenya, Mexico, Nigeria, Ukraine, and members of the Association of Southeast Asian Nations (ASEAN) and the GCC.


“Circle’s support, as a leading firm in the development of digital applications to the payments system, is invaluable in helping PIFS to deliver useful advice to emerging market regulators across the globe,” said Hal S. Scott, president and chairman of PIFS and emeritus Nomura Professor of International Financial Systems at Harvard Law School.


“For almost 30 years, PIFS has brought together academics, government and industry to address critical challenges facing the world’s diverse economies,” said Heath Tarbert, Circle’s chief legal officer and head of corporate affairs, and member of PIFS’ board of directors. “PIFS provides one-of-a-kind training programs for market regulators at a time when technological innovations like payment stablecoins like USDC are changing how money moves around the world. Circle is proud to support the Emerging Markets Scholarship Program, and to do so via USDC makes it all the better.”


Before joining Circle, Tarbert was a senior fellow at Harvard Law School/PIFS from 2014-2017. He served in leadership positions in the private sector and all three branches of the U.S. government and across key regulatory agencies. Most recently, Tarbert was the 14th chairman and chief executive of the CFTC and vice chairman of IOSCO.

Learn more about the PIFS Emerging Markets Programs here.

What you need to know: Native USDC is Launching on Celo

Native USDC is coming to Celo. Take a look below to learn more about Celo and what native USDC will mean for the ecosystem. 


Celo is a mobile-first, EVM-compatible blockchain that’s built for the real world and designed for fast, low-cost payments worldwide. The Celo ecosystem has over 1,000 projects in more than 150 countries, including enterprise partners like Deutsche Telekom, Google Cloud, and Opera, who are committed to Celo’s mission of creating economic prosperity for all. 


What you need to know

USDC issued by Circle will be native to Celo and is the official form of USDC for the ecosystem. USDC joins the ecosystem’s stablecoin use cases, including remittances, savings, lending, aid disbursement, peer-to-peer (P2P), and cross-border payments.  Businesses and developers can soon integrate USDC to provide fast, efficient, and secure mobile-first payments and stores of value with digital dollars. 


Benefits of native USDC 

  • Regulated, fully reserved and always redeemable 1:1 for US dollars
  • Enables institutional on/off-ramps like Circle Mint
  • Easy integration into existing Celo Apps


Why USDC on Celo 

  • A global, mobile-first user base 
  • An existing ecosystem of RWAs, including stablecoin use cases
  • A diverse network of fast-growing Apps & projects


Upcoming Governance Proposal

Additionally, keep an eye out for a future proposal from cLabs to the Celo community that would enable users to pay for network gas fees on Celo with native USDC. 

We’re very excited about what native USDC means for the Celo ecosystem. Please reach out on Discord if you have any questions.

Understanding Web3 Wallets

Blog_SEO-understanding-web3-walletsImagine a world where your mobile device isn’t just a way to access your bank, but a standalone place to store value. A world where transactions aren’t slowed down by middlemen, but flow as easily as sending a text message. Web3 wallets offer a decentralized, transparent, and direct method to store value on mobile devices and interact with digital assets.

What are Web3 wallets?

Web3 wallets are tools designed to store digital assets and interact with blockchain technologies. Unlike traditional bank accounts, these wallets allow the storage and management of blockchain-based digital assets, including:

  • Stablecoins: Stablecoins like USDC can be stored, sent, and received using Web3 wallets. Web3 infrastructure allows stablecoin transactions to be settled more quickly and with reduced fees compared to traditional banking payments.
  • NFTs: Non-Fungible Tokens represent unique digital assets, like art or collectibles, and can be securely held in Web3 wallets.
  • Badges and loyalty gifts: Instruments like airline miles or rewards points from your favorite store can be tokenized and managed within Web3 wallets, providing a more direct connection between businesses and their customers. For example, Grab, a popular app in Singapore, is using Programmable Wallets to offer coupons for goods and services associated with high profile events like the Singapore Grand Prix.

Web3 wallets are often confused with traditional digital wallets, but they can have several key features that differentiate them from traditional digital wallets. 



Web3 Wallets

Digital Wallets

Blockchain Support

Designed to support operations on public blockchains.

Designed using legacy integrations provided by siloed enterprises.


Operates on decentralized networks, allowing for user control and ownership.

Tied to centralized financial institutions.

Asset Diversity

Ability to manage a wide variety of digital assets such as cryptocurrencies, NFTs, and other tokenized assets.

Primarily designed to handle fiat currencies, credit cards, and bank-related transactions.


Can interact with various decentralized applications and protocols across different blockchain networks.

Limited to transactions within the affiliated institution or network, less cross-platform support.

Security and Control

Provided through cryptography, allowing complete ownership of funds and assets.

More reliant on security managed by the service provider.

Innovation and Engagement

Enable users to engage with innovative decentralized services, such as DeFi platforms, DAOs, and more.

Generally restricted in scope and functionality, focused on traditional banking and payment services.

Custodial vs Non-Custodial Wallets

Web3 wallets come in various forms, including custodial and non-custodial wallets.

  • Non-custodial wallets: Non-custodial wallets do not entrust the custody of private keys to a third party. Instead, users maintain full control and responsibility over keys and  assets within the wallet.
  • Custodial wallets: Custodial wallets have private keys that are managed by a hosting business or other third party, which can enable account recovery and other features.

How to use a Web3 wallet

To understand how Web3 wallets can help your business, it can be helpful to understand the steps required to get started with most Web3 wallets today.

  • Download and install: The first step involves downloading and installing the desired wallet. Some wallets function as part of a mobile app, while others may be desktop applications or browser extensions. Either way, users are already expected to leave your application or open or download an entirely different app to learn and navigate.
  •  Set up the wallet: Once the wallet is installed, it needs to be set up. This usually involves creating a new wallet within the application, although existing wallet data can be imported using a private key or seed phrase from another wallet if available. This process may or may not be guided, and can take significant time to complete.
  •  Secure the wallet: Upon creating a new wallet, users will be asked to set up a strong password and may also be provided with a seed phrase – a sequence of words that acts as a recovery key for the wallet. This seed phrase is extremely important, as it can restore the wallet if the host device is lost. Web3 wallets implemented with Programmable Wallets from Circle* allows users to use PIN codes to authorize transactions instead, to reduce friction if desired.
  • Receive a public address: Once the wallet is secured, users will be able to view their public address. This is a unique identifier that can be shared with others when transfering cryptocurrency. It’s a unique code similar to an email address that designates a specific wallet to receive crypto transactions. Using Programmable Wallets to embed Web3 wallets make it easy for users to get their public address right from within an app. 
  • Send and receive digital assets: The wallet is now ready to send and receive assets on the blockchain. Other wallet holders, exchanges, or applications can use wallet’s public address to transfer crypto or view public information like asset balances of the wallet.

Security measures for Web3 wallets

In addition to steps required for setting up Web3 wallets, there are considerations that must be made to enhance the security of Web3 wallets to protect user funds.

  •  Safeguard private keys: For non-custodial wallets, private keys must be stored securely by the users and never shared with anyone. Writing them down on paper and storing them in a secure location can be one effective method. For users less familiar with Web3 security, Programmable Wallets allow businesses to offer custodial wallets and secure private keys on behalf of their customers.
  •  Regularly update wallet software: Wallet software needs to be kept up-to-date, as developers may need release updates that fix bugs and security vulnerabilities. Circle’s Programmable Wallets are designed with security in mind, offering security best practices for developers to build.
  •  Guard against phishing attacks: Web3 wallet users should be aware of phishing attacks, where scammers try to trick them into providing private keys or connecting to malicious applications. Legitimate platforms and services will never ask for this information.

Programmable Wallets from Circle* are a convenient way for businesses to integrate digital wallets into their existing applications or new products, simplifying the process of setting up and using a Web3 wallet.

The Future of Web3 wallets

As blockchain technology continues to mature and become embedded in everyday applications, Web3 wallets are poised to play a greater role in the internet financial system. As the digital asset industry grows, businesses will need to continue making these wallets as intuitive as possible, removing barriers for new users.

Web3 wallets are a big step forward in the digital world, changing how we think about digital transactions and ownership. Programmable Wallets from Circle allows businesses to unlock greater user control and security, seamless use cases, and easy integration with existing platforms.

If your business is interested in integrating Web3 wallets into your products or services, check out our Programmable Wallets wallet-as-a-service product*. A part of the Web3 Services product line, Programmable Wallets allow you to embed secure wallets in your app in minutes, onboard users with familiar UX, and scale transactions effortlessly.



What is a Web3 wallet?

A Web3 wallet is a digital tool that enables interaction with decentralized applications and blockchain technologies. It allows users to store, manage, and transact with digital assets like cryptocurrencies, NFTs, and more.

What are the different types of Web3 wallets?

Web3 wallets can be divided into two main types: Non-custodial wallets, where users have full control over their keys; Custodial wallets, where a third party maintains control. Programmable Wallets allow businesses to choose between the two to provide what will work best for their use case.

How do I choose the best Web3 wallet for my business?

Choosing the best Web3 wallet depends on the needs of your business. Custodial wallets prioritize security and ease of use, while non-custodial wallets give users greater control and can be designed to connect to more Web3 applications. Programmable Wallets can be used to offer either type and provide additional customization options.

How do users secure Web3 wallets?

Web3 wallets are secured using a private key, which can be controlled by the user or by businesses providing Web3 wallets through Programmable Wallets from Circle.

Can I use my Web3 wallet to store non-fungible tokens (NFTs)?

Most Web3 wallets, including those generated using Programmable Wallets can be used to store, manage, and transact with NFTs, alongside other digital assets.

*Programmable Wallets and Smart Contract Platform application programming interface (“API”) is offered by Circle Technology Services, LLC (“CTS”). CTS is not a regulated financial services company and the API does not include financial, investment, tax, legal, regulatory, accounting, business, or other advice. For additional details, please click here to see the Circle Developer terms of service.

Webinar Recap: 2023 Highlights and 2024 Horizons

2023 was a year of expansion and growth for Circle. We launched new product offerings like Web3 Services and the Cross-Chain Transfer Protocol that add utility for Web3 developers and make it easier to access and use the internet financial system. We also made significant strides in globalizing our business, acquiring new licenses and conditional approvals that will allow us to bring USDC and EURC to more businesses than ever before.

In our year-end “2023 Highlights and 2024 Horizons” webinar, members of Circle’s executive leadership team also spoke about changes to the digital asset industry, the integrity of our business, and how we’re advancing our mission of raising global prosperity through the frictionless exchange of value.

Building infrastructure for the internet financial system

USDC is available all over the world as an accessible dollar stablecoin that can serve as a platform for increased commercial activity for millions of companies and billions of people. Circle CEO Jeremy Allaire explains how the internet financial system is being unleashed through this innovative form of open money as the world becomes increasingly interconnected:

Over the course of 2023, in countries like Singapore and France, we worked closely with regulators to become licensed and conditionally approved to offer our stablecoins. All of these efforts aim to continuously increase the liquidity available for USDC and EURC, making them easier to acquire and use.

Introducing Web3 Services has been a critical undertaking for Circle in 2023, allowing businesses across a wide range of industries to quickly and easily integrate digital wallets and other Web3 capabilities into their workflows or product offerings. Combined with other 2023 releases like the Smart Contract Platform and Circle Gas Station, we’re providing easy-to-use developer tools to accelerate Web3 adoption and the growth of the internet financial system.

Business integrity and advancing regulatory clarity

The integrity of our business is a top priority and is a core component of  building the world’s largest and most widely-used stablecoin network. Chief Compliance Officer Mandeep Walia expanded on how we aim to provide the highest possible level of integrity for management of both our data and the value that moves on Circle’s digital currency networks.

As we maintain and continuously refine our high operating standards, policymakers within the US are moving forward on bringing regulatory clarity into greater focus for digital assets and stablecoins, as explained by Chief Strategy Officer and Head of Global Policy Dante Disparte:

As more nations around the world move towards regulatory clarity on important topics related to digital assets and stablecoins, more work will need to be done to harmonize different regulatory treatments into a global framework that can unlock the full potential of the emerging internet financial system.

On to 2024

2024 should bring even more progress to our products and stablecoin network, accelerating access and utility. We are continuing to develop our Web3 Services offerings, making it even easier to access the internet financial system. New and stronger relationships with financial and technology partners will add depth to USDC and EURC liquidity around the globe, and advancing regulatory clarity will allow Circle to continue to meet and exceed standards set by policymakers for the security of our network and the integrity of our business.


Want to hear more from our ELT team? Watch the full webinar, or learn more about how USDC and Web3 Services can help your business.

Web3 Services December Updates

Blog_w3s-decWe’re excited to share several updates we’ve launched to help developers build Web3 apps faster and better! Our updates include a step-by-step interactive tutorial to start building with our web SDK, multi-user roles to facilitate building projects as a team, and a new metrics dashboard to understand usage. Read on to learn more about our updates below.

An Important Note

Before we jump into the new projects we’ve launched, we’d like to inform you of Web3 Service’s planned migration from ETH Goerli to ETH Sepolia. In response to the Ethereum Foundation’s deprecation of Ethereum Goerli testnet, Web3 Services will shift support to ETH Sepolia with full feature parity to provide sustained support for the Ethereum testnet:

  • Web3 Services support for ETH Sepolia will be available on January 10th, 2024 (ET)
  • Web3 Services deprecation of ETH Goerli is scheduled for January 31st, 2024 (ET)

New additions

Start building with our web SDK

Developers can start creating web-based wallet experiences with our user-controlled wallets web SDK. Our latest quickstart offers developers a step-by-step learning experience and a comprehensive walkthrough in under two hours. Learn to:

  • Create a user and set up their wallets
  • Enable end users to define their pin and recovery method
  • Receive testnet tokens and check wallet balance
  • Initiate gasless transactions and enable end users to confirm transactions


Build together with role-based access

With the launch of multi-user support, you can now easily co-develop projects with your team. Access the Developer Console to add or remove users or set permissions to define the access level for each user for more control. As an admin, you have full control to define who should be granted the same level of “Admin” access or only require “View-only” access. Learn more about user roles and how to set them up here.




A clear look into usage metrics

With the launch of the API metrics dashboard, you can now see a clearer picture of your project status. This new metrics dashboard in the Developer Console provides a clear view of your API requests to provide further insight into data points and help identify potential issues. With the metrics dashboard, you’ll have a clearer look into:

  • The total number of API requests sent
  • Number of API errors received (either on the client-side or server-side)
  • The latency of API calls
  • Success rate of API calls


Learn to build with Circle



This mini video series walks developers through the full experience of building with developer-controlled Programmable Wallets. Explore how the dashboard streamlines your Web3 development process, offering tools and services for secure wallet creation, transaction monitoring, and more.




Bhushit Agarwal, Senior Software Engineer at Circle, sits down with Circle Director of Community, Sam Sealey, to discuss how he has developed a programmable wallet integration with Mastodon to unlock a decentralized social economy.


Learn how Circle’s Gas Station enables developers to abstract gas fees from their end-users during a blockchain transaction using Programmable Wallets, vastly improving the user’s experience

Live workshops

Follow us on Discord and join us for our live workshops!


Programmable Wallets and Smart Contract Platform application programming interfaces (“API”) are offered by Circle Technology Services, LLC (“CTS”). CTS is not a regulated financial services company and the APIs do not include financial, investment, tax, legal, regulatory, accounting, business, or other advice. For additional details, please click here to see the Circle Developer terms of service.

Upcoming Support for Sepolia Test Networks

We’re expanding support for USDC and EURC on a number of Sepolia test networks to better serve developers building with Circle’s stablecoin protocols and platform services.

Please note that Goerli test networks are expected to no longer be actively maintained by the community moving forward. We encourage developers to migrate to Sepolia at your earliest convenience.


Planned rollout for January 8 – 19, 2024

  • USDC
    • Launches on Arbitrum Sepolia
    • Launches on Base Sepolia
    • Launches on Ethereum Sepolia
    • Launches on OP Sepolia
  • EURC
    • Launches on Ethereum Sepolia
  • CCTP
    • Launches on Arbitrum Sepolia
    • Launches on Base Sepolia
    • Launches on Ethereum Sepolia
    • Launches on OP Sepolia
  • Circle Mint and Faucet
    • Support USDC on Arbitrum Sepolia
    • Support USDC on Base Sepolia
    • Support USDC on Ethereum Sepolia
    • Support EURC on Ethereum Sepolia
    • Support USDC on OP Sepolia
  • Programmable Wallets and Smart Contract Platform

We expect 1-2 hours of downtime for Circle Mint Sandbox APIs during the migration to Sepolia for each USDC and EURC testnet deployment. Please refer to BuildOnCircle on X and our Discord for daily updates.


What is changing?

  • USDC will have new Sepolia testnet addresses for Arbitrum, Base, Ethereum, and OP. 
  • EURC will have new Sepolia testnet addresses for Ethereum.
  • CCTP will have new Sepolia testnet addresses for Arbitrum, Base, Ethereum, and OP. The attestation API will no longer support Goerli once the migration takes place. 
  • Faucet will no longer support USDC and EURC on Goerli test networks. Instead, you’ll be able to select and receive USDC and EURC on Sepolia test networks.
  • Circle Mint deposit addresses created on Goerli will be cleared. Sending USDC or EURC to cleared addresses will result in lost funds in Circle Mint sandbox. Any historical transfers and existing balances will remain the same.
  • Programmable Wallets and Smart Contract Platform will add support for Ethereum Sepolia on January 10, and deprecate support for Ethereum Goerli by the end of January 2024. At that time, APIs will no longer reflect data from Ethereum Goerli.

If you have questions about our Sepolia rollout or want to learn more about building with USDC and EURC, join the conversation in our Discord – or check out our self-serve developer portal to get started.

Circle Awarded its First Patent for Parallel Block Processing in Blockchains

This week, Circle earned its first patent for Parallel Block Processing in Blockchains – an innovative new technique, developed by Marcus Boorstin, Director of Engineering, that allows for simultaneous processing of multiple pieces of information – while still serially validating the blocks. 


“Circle first used Parallel Block Processing to process transactions for USDC on Solana, which has significantly higher-throughput than Ethereum,” said Boorstin. “Several of Circle’s products, including Circle Mint, must process on-chain information in order to register incoming deposits and outgoing withdrawals. The blockchain nodes to which our applications connect are sometimes slow and unreliable – so it can be difficult to process blockchain data quickly enough to keep up with the chain.”


Boorstin noted that ‘parallelism’, a common technique in software engineering, is about processing multiple pieces of information at once – but challenging when one block depends on the previous block. 


“Circle’s invention provides a technique for processing blockchain data in a parallel manner, while still serially validating all the blocks,” Boorstin said. 


Jeff Tang, Circle’s Chief Intellectual Property Counsel, heralds the win as a major milestone for Circle. 


“Marcus’s invention couldn’t come at a better time as we gain traction on Solana,” said Tang. “Patents act as a receipt of innovation and are a reflection of the hard and novel work done by our developers everyday. This patent will help protect our open architecture and grants us freedom to operate. I’m excited for new innovations to come in 2024.”


View the full details of the patent here

Getting Started with USDC on Solana

USDC is the most widely used dollar-backed stablecoin in the Solana ecosystem, which is home to many popular NFT, Payments, and DeFi apps for FX, trading, borrowing, lending and more.


If you have USDC on Solana today, it’s easy to jump right into these apps and begin transacting:

01 Exchange, Cube Exchange, Drift Protocol, Hxro Network, Jupiter Exchange, Kamino, Mango Markets, marginfi, Meteora, Openbook, Orca, Phoenix, Raydium, Saber, Solend, Tulip, Zeta


Explore the broader Solana ecosystem with this overview map created by Phantom:

Source: Phantom


There’s also many ways to access USDC on Solana for new users. Check out our guide below for a variety of fast and user-friendly options.


Getting started for the first time


Get USDC on Solana from fiat on-ramps

Coinbase Wallet and Phantom make it easy to convert your local currency (e.g. USD) to USDC on Solana via fiat on-ramps like bank transfers and debit card deposits.


How it works via Coinbase Wallet when funding with a Coinbase account:

  1. Download Coinbase Wallet on desktop or mobile
  2. Set up your wallet and securely store your credentials
  3. Tap “Buy” and select “Buy or transfer from Coinbase”
  4. Login or link your Coinbase account (separate app)
  5. Select USDC
  6. Enter in an amount, and your payment information. Note: there are no Coinbase fees for using bank transfers to buy USDC.
  7. On the Order preview screen, change the Network from Ethereum to Solana
  8. Select Confirm
  9. Once completed, USDC on Solana will appear in your Coinbase Wallet

How it works via Coinbase Wallet when funding with a third party:

  1. Download Coinbase Wallet on desktop or mobile
  2. Set up your wallet and securely store your credentials
  3. Tap “Buy”
  4. Select USDC as the asset, and Solana as the network
  5. Select a payment method and provider you’d like to pay with
  6. Click “Continue to payment” and complete the remaining prompts
  7. Once completed, USDC on Solana will appear in your Coinbase Wallet


How it works via Phantom:

  1. Download Phantom on desktop or mobile
  2. Set up your wallet and securely store your credentials
  3. Tap “Buy” and select USDC on Solana
  4. Choose an on-ramp provider
    • MoonPay (currently zero-fee)
    • Coinbase Pay
    • Robinhood Connect
  5. Provide your payment information
  6. Upon completion, you’ll receive USDC on Solana in your wallet

Note: You can also use Solflare and other digital wallets for similar accessibility.


Current users of crypto or USDC on a different blockchain


Get USDC to Solana from cross-chain bridges

Allbridge Core makes it easy to swap your crypto (e.g. ETH on Ethereum) or USDC on a different blockchain (e.g. USDC on Ethereum) to USDC on Solana.


How it works:

  1. Navigate to Allbridge Core on desktop or mobile
  2. Tap “Connect Wallet” and connect your external wallet
  3. Select the asset that you want to swap (e.g. USDC on Ethereum) for USDC on Solana
  4. Select USDC on Solana as your destination asset
  5. Click “Send” and approve the transaction
  6. Upon completion, you’ll receive USDC on Solana in your wallet

Note: Phantom has a “Cross-Chain Swapper” function powered by Allbridge Core that you can access directly in your wallet for more convenience. 


Deposit USDC into an exchange and withdraw as USDC on Solana

Coinbase enables users to send USDC from an external wallet to a Coinbase account on a variety of blockchains, such as Ethereum. Then, it’s easy to withdraw USDC on Solana back to a Solana-compatible external wallet like Coinbase Wallet or Phantom.


How it works:

  1. Open a Coinbase account
  2. Tap “Receive” and select USDC
  3. Choose the network that you currently hold USDC in your external wallet (e.g. Ethereum)
  4. Tap “Copy” to copy your Coinbase-specific wallet address
  5. Use your external wallet (e.g. MetaMask) to paste your Coinbase-specific wallet address and send your USDC. Upon completion, USDC will appear in your Coinbase account.
  6. Download Phantom on desktop or mobile
  7. Set up your wallet and securely store your credentials
  8. Tap “Receive” and tap the copy icon for your Solana wallet address
  9. Navigate to “Home” for your Coinbase account
  10. Tap “Send” and select USDC
  11. Paste your Solana wallet address and send your USDC
  12. Upon completion, USDC will appear in your Phantom wallet

Make sure to follow @Circle on X for the latest news on USDC on Solana.

Decentralized Insurance “R-Pools” for Recoverable Wrapper Tokens

  • In conjunction with Stanford researchers, Circle Research introduced the concept of “R-Pools” which can be used to exchange unsettled recoverable wrapped tokens for base tokens.
  • On November 30, 2023, Circle Research presented and published this idea as part of the DeFi Security track at the ACM Conference on Computer and Communications Security held in Copenhagen. 
  • It is recommended for the reader to familiarize themselves with the research from our recent post on recoverability, which can be found here.

Previously, we introduced recoverable wrapper tokens as a configurable, programmable mechanism to add recoverability features that can help protect developers and users from theft and illicit finance. Different configuration sets suit different contexts and use cases. These sets can range from a general recoverable asset for consumers to a wrapper issued and arbitrated by DeFi protocols to protect their locked funds. 


In the latter scenario, the DeFi protocol could still accept normal base tokens, but wrap them immediately to keep them protected and recoverable. When a user withdraws from the protocol, the withdrawal is in recoverable wrapped form. At this point, the user could spend the tokens on a service or entity that accepts recoverable wrapped assets, or they could wait for the settlement period to elapse before unwrapping and subsequently spending the base tokens. However, many DeFi services may not accept recoverable wrapped assets, as they do not expect funds to be revoked post-deposit. What if the user wants to spend the wrapped tokens immediately on another DeFi service, and is even willing to pay a fee to do so? 


Circle Research teamed up with Stanford researchers (Dan Boneh and Qinchen Wang) to dive deeper into this thought experiment and answer this very question. We invented the concept of the “R-Pool” which is used to exchange unsettled recoverable wrapped tokens for base tokens. Another way to think about the R-Pool is as a decentralized insurance protocol. In our paper, we discuss the design challenges of the R-Pool and two potential types of implementation: AMM and order book. 


On November 30, 2023, we presented and published this research as part of the DeFi Security track at the ACM Conference on Computer and Communications Security held in Copenhagen. We invite you to read the paper to learn more and check out proof-of-concepts for the R-Pool in our open-source recoverable wrapper repo


Have a question or Interested in a research collaboration? Please reach out to

Web3 Services November Updates

Blog_w3s-novWe’re excited to introduce the latest features and updates under Circle’s Web3 Services, allowing for further improved experiences for both developers and end-users! This month’s updates include important features like web SDK and server-side SDKs that help developers build faster, reach wider audiences, and create cross-platform, interoperable experiences. Read on to learn more.

Smart Contract Platform update: deprecating Avalanche support

We are deprecating Avalanche support for Smart Contract Platform on Avalanche mainnet and testnet. Deployment, import and function execution will no longer be supported. This decision was made with user experience in mind, and our team is working on exploring ways to improve developer tooling support. We hope to resume Avalanche support for Smart Contract Platform soon.

Build faster, across more platforms

WebSDK for user-controlled wallets

Create a unified experience for your users across mobile and web. Web SDK for user-controlled wallets uses the same underlying infrastructure and MPC cryptographic technology as the mobile SDK to securely handle your users’ wallets and transactions. Similar to the experience on mobile apps, users no longer have to deal with lengthy seed phrases–all they need is a six digit PIN and security questions as a recovery method to be able to transact securely on the blockchain. Leverage the interoperability offered by using both the web and mobile SDKs to easily create streamlined, cohesive, and secure on-chain experiences for your users.


Smart Contract Platform – Templates

Create and deploy customized smart contracts to create unique on-chain experiences, in minutes. Smart Contract Platform now offers a curated and security-audited repository of the most common use-cases for smart contracts that you can customize, including: minting ERC-20, ERC-721, and ERC-1155 tokens. These popular contracts can be used to create loyalty points, incentivize user engagement, or create unique NFTs like collectibles in gaming.

Developers not only have the ability to create and deploy these customized templates programmatically via APIs–the Developer Console offers a no-code option that those who are unfamiliar with programming can leverage to create these experiences, or mint NFTs, with just a few clicks.





Server-side SDKs

Circle now offers server-side SDKs in Node JS to help you interact with the APIs for Programmable Wallets and Smart Contract Platform–further simplifying building with Web3 Services and accelerating your app’s development time. Leverage this important resource to interact with Circle’s server-side infrastructure more efficiently and minimize the amount of steps you need to go through to set up your environment so that you can reduce the lines of code you need to write to develop your app! Download the SDKs here: 

New API endpoints – Sign message and sign typed data

‘sign message’ and ‘sign typed data’ APIs are a crucial part of today’s Web3 ecosystem. They provide verifications and confirmation messages that help establish ownership of wallets. These newly launched endpoints empower developers to make programmable wallets more powerful and robust by enabling seamless interactions with dApps and smart contracts, and facilitate personalized experiences like token-gated experiences. Leverage these endpoints to integrate with WalletConnect, so that your users can access and interact seamlessly with the most popular dApps.

Deliver better end-user experiences

Transaction signing with Biometrics

Developers building on Programmable Wallets are now able to further streamline Web3 transaction experiences with biometrics signing! With SDKs available for both iOS and Android, developers can build Web2-like experiences that leverage biometric checks like fingerprint or facial scans to ensure the authenticity of a signature, and verify the identity of the signer. In addition to streamlining the end-user experience, this technology offers enhanced enterprise-grade security that users are already accustomed to and trust. Learn more about how you can support biometrics signing in your Web3 apps by viewing the changelog here.image3


Gas Station for developer-controlled wallets

Last month, we announced the launch of Programmable Wallets’ Gas Station feature, enabling apps built with user-controlled wallets to offer gas-less transaction experiences for users. We’re excited to announce that this powerful feature is available for developer-controlled wallets too! Any developer building with Programmable Wallets can now remove friction caused by network fees (gas) from their end-users’ experience by sponsoring their gas fees. Developers don’t need to worry about sourcing native tokens either–all they need is a credit card on file, and Circle will handle the sourcing and transferring of gas fees.

Learn more on how to build with Circle

We’re excited to share a series of learning resources– interactive quickstarts, blogs, and video walkthroughs–that will guide you through creating your first wallets and initiating transactions with Web3 Services:


Build an iOS app that generates Web3 wallets

This video uses Circle’s new sample app for integrating social sign-in functionality with web3 wallet generation to build an iOS app that generates User-Controlled Programmable Wallets during a social sign-in flow.

Dive into the infrastructure and benefits of Programmable Wallets and learn how to create and manage Web3 wallets as an enterprise developer through Circle’s Web3 Services.



Live workshops

Follow us on Discord and join us for our live workshops!


Programmable Wallets and Smart Contract Platform application programming interfaces (“API”) are offered by Circle Technology Services, LLC (“CTS”). CTS is not a regulated financial services company and the APIs do not include financial, investment, tax, legal, regulatory, accounting, business, or other advice. For additional details, please click here to see the Circle Developer terms of service.

Getting Started With Programmable Wallets: Circle’s Wallet as a Service Product

Blog_SEO-wallets-getting-startedDigital wallets are essential to the Web3 ecosystem, providing a way for users to store and send digital currencies and serving as a hub to interact with applications. But digital wallets can be difficult for everyday users to set up and keep secure. Many wallets exist as independent products that can’t be easily integrated into existing payments platforms or applications.

Programmable Wallets from Circle offer a simple but powerful way to add the capabilities of digital wallets into existing apps and infrastructure, unlocking near-instant, low-cost payments with USDC, EURC, and other digital currencies and assets.

Programmable Wallets can be configured to interact with decentralized finance (DeFi) applications, NFT marketplaces, and more throughout the Web3 ecosystem, or can be customized to only interact with specific digital assets and whitelisted programs. REST APIs and mobile SDKs make it easy to get started quickly with Programmable Wallets and add new capabilities that can be seamlessly integrated into your user experience.

Why use Programmable Wallets?

Programmable Wallets are ideal for businesses and applications that need an easy-to-implement way to give customers the ability to send, spend, and save digital currencies like USDC and EURC. 

Transactions using digital currencies can move value around the world in minutes and cost less than a penny to execute. Other forms of digital money from traditional banks or fintech providers lack cross-compatibility, and can require lengthy (up to six days) and expensive (up to $50 per international wire) processes to move between platforms and countries. USDC can be sent to and from Programmable Wallets to other digital wallets in minutes, even those on different blockchains, using infrastructure provided by Circle.

Embedding Programmable Wallets into your platform or application, makes it easy for your users to take advantage of the global reach and low cost of digital currency transactions. Allowing customers to access and use digital currency can help boost sales and improve the customer experience in global and cross-border transactions.

Programmable Wallets allow you to unlock Web3 for your customers, and the flexible wallet architecture–either developer-controlled or user-controlled wallets–allow you to create a tailored experience for end-users. 


  • Choose to unlock Web3 for your customers, providing experiences with digital collectibles, NFTs and decentralized applications
  • Delight customers with new ways of engaging and interacting via loyalty programs, collectibles and social media
  • Allow more experienced customers to control their own wallets, giving them full control of their access, interactions and how they engage with the capabilities of Web3.

How to get started with Programmable Wallets

Getting started with Programmable Wallets means you’ll need to decide which infrastructure model is right for your business or application. User-controlled wallets give your customers greater control, allowing them to be the only party with the rights to initiate transactions and interact with a wide variety of digital assets and on-chain smart contracts.

By contrast, developer-controlled wallets allow the user experience to be more closely managed, restricting interactions to particular applications or assets and only initiating transactions for application-specific tasks.

Once you’ve decided the type of wallet to offer customers, you can learn more about initial setup for user-controlled or developer-controlled wallets. Circle developer docs give an in-depth view into adding additional capabilities to Programmable Wallets and guidance on best practices.

If you want to test or experiment with Programmable Wallets, it’s easy to sign up for an account on the Developer Console and create an API key. Use the key to bring your first wallets to life, then build a prototype to allow interactions with specific protocols or digital currencies to fine tune your user experience.

Circle’s Web3 Services developer console and developer resources make it easy to integrate Programmable Wallets into applications tailored to your specific use case, and easy for users to set up their wallets.

Programmable Wallets are an ideal solution to capture the convenience and cost benefits of using digital currencies like USDC and EURC for your users. As momentum continues to grow among Web3 platforms and applications, Programmable Wallets  make it simple to give customers access to the best of what the internet can offer.

Ready to get started with Programmable Wallets? Sign up through the Developer Console.


Programmable Wallets application programming interface (“API”) is offered by Circle Technology Services, LLC (“CTS”). CTS is not a regulated financial services company and the API does not include financial, investment, tax, legal, regulatory, accounting, business, or other advice. For additional details, please click here to see the Circle Developer terms of service.

A Configurable and Programmable Wrapper Mechanism for Recovering ERC-20 Tokens

  • Circle Research seeks to enhance the security of ERC-20 tokens through the implementation of a customizable and programmable recovery mechanism.
  • Recoverable wrapper tokens can protect developers and users from thefts and illicit finance. 
  • Circle Research presents multiple configuration sets, or ways to implement and design tailored recoverable wrapper tokens.

Barrier to Entry: Theft and Security

Annual losses due to token theft and accidents are in the billions of dollars. In 2021, $3.3 billion was stolen in crypto hacks, and that number jumped to $3.8 billion in 2022.

The immutability, or irreversibility of blockchain transactions is a fundamental characteristic that offers key benefits. However, it also presents challenges, such as rendering thefts and illicit activities permanent and irretrievable by default. This reality makes it hard for many retail users, consumers, and businesses to adopt blockchain systems.


Recoverable Wrapped Tokens

One way to protect assets from theft is to strengthen the security of asset keys and to improve the quality of Web3 code. A complementary approach, explored in depth last year by Stanford researchers including Dan Boneh, is to extend the ERC-20 interface to support asset recovery with the “ERC-20R.” In the same vein, the Circle Research team explored recoverable wrapper tokens, building upon the aforementioned Stanford research paper. Our effort aims to construct a configurable and programmable recovery mechanism to benefit both developers and users of ERC-20 tokens.

This proposed mechanism revolves around recoverable wrapper tokens. Users can wrap their ERC-20 asset by locking them in the recoverable wrapper token contract in order to receive an equal number of wrapper tokens in return. Wrapping the tokens protects users from thefts, and still maintains most of the utility found in the token’s base form. One core difference, however, is that recoverable wrapper tokens can be recovered back to the sender within a certain time window post-transaction (say, 24 hours). Consequently, each user will have two distinct balances of the token: a settled balance (non-recoverable) and an unsettled balance (recoverable). Only settled tokens may be unwrapped back into their base form.

Building beyond the thesis put forth in the ERC20R paper, we present multiple configuration sets, or ways to implement and design a recoverable wrapper token, each with their own use cases and attributes. For instance, one version is an arbitrated wrapper appropriate for a targeted, designated ecosystem with a trusted governance. Another version offers more of a cancellable send button, where transactions simply take a longer, custom period of time to settle than the chain’s finality. Different configuration sets can still be interoperable with each other, as long as they conform to a shared interface. We provide the IERC20R contract as this interface. 

As an example, we developed the arbitrated wrapper version for protecting USDC or any token (completed audit report coming soon). This will soon be available for Circle’s recently unveiled Smart Contract Platform, so developers have a template to experiment with and provide token recoverability features to their users.

We invite you to check out the whitepaper and Github repo for more information. We highly encourage you to test the new configuration sets and contribute to the repository.


On the Horizon

This research brings us one step closer to unlocking improved blockchain use cases such as cancellable payments, arbitrated ecosystem tokens, or protection for a DeFi protocol’s assets. However, one challenge yet discussed is composability with the existing DeFi ecosystem when the wrapper token is used in that context. 

In our next installment from Circle Research, we will discuss this challenge in depth as well as a potential solution, called “RPools.” This joint collaboration with Qinchen Wang and Dan Boneh from Stanford will be presented at the ACM CCS conference DeFi Security workshop in Copenhagen on November 30. Stay tuned! 


Have a question or Interested in a research collaboration? Please reach out to

Bridged USDC Standard | Circle

Blog_bridged-usdc-standardDeploy a bridged USDC token contract with optionality for native issuance

Permissionless composability is one of the hallmarks of Web3, contributing to the rapid growth of new applications and blockchain networks by leveraging existing open technology. Circle’s USDC is no exception, stemming from the innovations of the ERC-20 standard and countless third-party frameworks to become the trusted dollar-backed stablecoin that it is today.

As of November 2023, USDC is issued and circulating natively on 15 blockchains – 7 more than last year – and yet it is also clear to Circle and the broader community that many more blockchains may emerge and rise to prominence over the next several years. These new blockchains could benefit significantly from having access to USDC.


Native USDC vs. Bridged USDC

As we all know, native USDC provides unique advantages over bridged forms of USDC. Native issuance of USDC means that developers and users can trust that the asset they’re using is fully reserved and always redeemable 1:1 for US dollars. Native USDC can be supported in Circle products like Circle Mint and Cross-Chain Transfer Protocol (CCTP), contributing to deeper ecosystem interactions and opportunities.


Native USDC
Bridged USDC

Issued by Circle, a regulated fintech

Backed by US dollars and always redeemable 1:1

Official form of USDC on a given blockchain

Interoperable with multiple blockchain networks via CCTP

Created by a third party

Backed by USDC on another blockchain locked in a smart contract

Many disparate forms can result in a fragmented user experience

Not compatible with CCTP

Interestingly, bridged forms of USDC play a key role in solving the “cold start” problem for generating activity on new blockchain networks. Unlike native USDC, bridged forms of USDC can be spun up quickly by new L1 and L2 rollup teams, in addition to third-party bridge deployers. While bridged USDC is unofficial and not issued nor redeemable by Circle, it serves as a proxy to USDC that’s extensible to any ecosystem where bridging is made possible. This helps developers bootstrap stablecoin liquidity for their applications and enables users to begin exploring new use cases early.

Ideally, Circle could bring native USDC to every secure, safe and promising new blockchain network as soon as it launches. But with the meteoric rise of scaling solutions like L2s/L3s, modular blockchains, and new high performance L1s, Circle faces a significant challenge with ecosystem innovation outpacing the speed of new USDC deployments.

As a result, Circle has often been launching native USDC on new blockchains after a large amount of USDC liquidity had already been bridged by third parties. While it’s true that developers and users can readily migrate from bridged USDC to native USDC, the ideal scenario would be to avoid a migration entirely.

So, how can Circle simultaneously enable an early path to native USDC for new blockchains, solve the cold start problem, and avoid the pitfalls of liquidity fragmentation and lengthy migrations?

This brings us back to permissionless composability and the power of community.

Introducing: Bridged USDC Standard

Bridged USDC Standard is a specification and process for deploying a bridged form of USDC on EVM blockchains with optionality for Circle to seamlessly upgrade to native issuance in the future.

The result is a secure and standardized way for any EVM blockchain and rollup team to transfer ownership of a bridged USDC token contract to Circle to facilitate an upgrade to native USDC, if and when both parties deem appropriate.


  • Permissionless and equitable: Anyone can incorporate the standard to deploy a bridged USDC token contract, such as new L1 and L2 rollup teams, or chain-sponsored third-party bridge deployers
  • Standardized and extensible: The process to securely transition ownership of a bridged USDC token contract to Circle follows a set procedure that’s also extensible to bridged EURC
  • Secure and audited: The standard consists of open-source ERC-20 contract code based on the same audited USDC smart contract that has secured billions of dollars in liquidity

Here’s how it works:

  1. Third-party team follows the standard to deploy their bridged USDC token contract.

  2. Bridged USDC is used to bootstrap initial liquidity in the ecosystem and begins to proliferate.

  3. Bridged USDC reaches a significant supply, amount of holders, and number of app integrations.

  4. Circle and third-party team jointly elect to securely transfer ownership of the bridged USDC token contract to Circle.2

  5. Upon obtaining ownership, Circle upgrades bridged USDC to native USDC and seamlessly retains existing supply, holders, and app integrations.3

The benefits obtained by upgrading in-place are numerous, as the contract address, user balances, and application integrations are all maintained, ensuring a seamless experience for developers and users. Liquidity fragmentation and migration learning curves are no longer obstacles to overcome.

Benefits for all actors in the value chain

  • Blockchains: Get bridged USDC into the hands of developers and users early with the potential for a seamless upgrade to native USDC in the future.
  • Developers: Build on bridged USDC with a contract address that will persist after an upgrade to native USDC. No code change needed to support a new asset.
  • Users: Store, pay, trade, borrow, and lend with bridged USDC that automatically becomes native USDC upon an upgrade. No need to swap to a new asset.
  • Everyone: Avoid the time-consuming liquidity migration process of educating and incentivizing users to move from bridged USDC to native USDC.

Implementations are already live

We’re proud to share that the teams at Linea and Scroll have already followed the standard for their bridged USDC token contracts on their respective testnet and mainnet networks. Recently on testnet, both Linea and Scroll were able to conduct a secure transition of their respective bridged USDC token contracts to Circle’s ownership, which successfully simulates the equivalent procedure for mainnet.


What this means for modular EVM architectures

Circle expects to expand upon the available configurations for the standard to match the specifications of the most common modular EVM architectures, such as the OP Stack. The vision for Bridged USDC Standard is to be widely incorporated into Rollup as a Service (RaaS) offerings, such that it’s easy to deploy a new blockchain with a templatized bridged USDC token contract that’s compatible with the standard by default.

The standard can also be extended to Circle’s euro-backed stablecoin by incorporating the specification when deploying a bridged EURC token contract. We’re also exploring how the standard can be re-factored for non-EVM blockchains and where commonalities exist to provide a scalable solution.


How to get started

If you’re a new EVM blockchain team or you’re a third-party bridge deployer working closely with one, dive into our implementation guide to learn how to deploy a bridged USDC token contract that follows the standard today.

Please reach out on Discord to help us assess further improvements and extensions. We welcome all feedback and innovative approaches from the community.


Is Circle obligated to upgrade bridged USDC to native USDC?

No. Bridged USDC Standard grants Circle the option, but not the obligation, to obtain ownership of the token contract and upgrade to native USDC. In general, Circle’s decision to upgrade a particular form of bridged USDC to native USDC may be subject to additional terms and conditions.


Can an existing bridged USDC token contract be sufficiently upgraded to match the Bridged USDC Standard?

Unfortunately, no. An existing bridged USDC token contract cannot be upgraded to match the Bridged USDC Standard if the original contract deployment did not follow the standard’s technical requirements.


If I’m a third-party bridge provider, can I partner with a blockchain team to deploy a bridged USDC that follows the standard for their canonical bridge?

Yes, absolutely. Blockchain teams may benefit from the technical expertise and resources that third-party bridge providers can provide for deploying a bridged USDC token contract that follows the Bridged USDC Standard.


What’s the threshold of supply or holders that Circle is looking to see before considering upgrading a bridged USDC contract to native USDC?

There is no exact threshold of supply or holders. Circle evaluates an assortment of factors prior to considering a native deployment of USDC, or in this case, an upgrade of bridged USDC to native USDC. In general, both the size and growth rate of bridged USDC supply, holders, and apps supported will contribute significantly to how Circle prioritizes native issuance for USDC.


Is the Bridged USDC Standard appropriate for EVM subnets, appchains, and parachains in the Avalanche, Cosmos, and Polkadot ecosystems respectively?

While it’s true that the standard can be followed to deploy bridged USDC on any EVM blockchain, USDC already exists natively in the Avalanche, Cosmos, and Polkadot ecosystems:

  • USDC for the Avalanche ecosystem is natively issued on Avalanche C-Chain and can be transferred to Avalanche subnets via Avalanche Warp Messaging (AWM).
  • USDC for the Cosmos ecosystem is natively issued on Noble and can be transferred to Cosmos appchains via Inter-Blockchain Communication (IBC).
  • USDC for the Polkadot ecosystem is natively issued on Asset Hub and can be transferred to Polkadot parachains via Cross-Consensus Messaging (XCM).

As such, Circle intends for USDC to be accessed via the established protocols in each ecosystem. However, each sovereign subnet, appchain, and parachain is free to choose if they prefer to deploy a bridged USDC token contract.


You mentioned Bridged USDC Standard can be extended to bridged EURC as well. What about other bridged ERC-20 token contracts?

In time, we intend to explore up-leveling the standard to provide a generalized framework for any bridged ERC-20 token contract – ideally helping to address liquidity fragmentation for the broader industry of asset issuers.

We’re also open to collaborating with the community on other approaches to help solve this shared problem, such as xERC-20 (aka ERC-7281).


I have ideas for how you could extend the Bridged USDC Standard to additional architectures. How can I contribute?

Please reach out on Discord to help us assess further improvements and extensions. We welcome all feedback and innovative approaches from the community.



1. Bridged USDC Standard grants Circle the option, but not the obligation, to obtain ownership of the token contract and upgrade to native USDC. Additionally, Bridged USDC Standard must be incorporated prior to deploying a bridged USDC token contract as it cannot be retroactively applied. The requirements provided are for informational purposes only and will apply should Circle choose to upgrade a particular form of bridged USDC to native USDC. These requirements do not constitute an offer to upgrade a particular form of bridged USDC. Circle’s decision to upgrade a particular form of bridged USDC to native USDC may be subject to additional terms and conditions. As noted in Section 8 of the USDC Terms of Use, bridged forms of USDC are subject to certain risks and are not issued by Circle.

2. The target blockchain will undergo Circle’s internal Blockchain Due Diligence Process. That process involves reviews for both compliance and risk factors, as well as coverage for legal and technology risks, prior to approval. The diligence focuses on crypto and blockchain nuances, and an assessment of the strategic, financial, operational, technology, legal, and regulatory risks that are present.

3. During the transition from bridged USDC to native USDC, Circle will securely burn the native USDC that was locked in the bridge smart contract on the origin chain (e.g. Ethereum).

Fueling the Rise of USDC: Gas Abstraction & Gelato’s Vision


“At Gelato, USDC isn’t just currency—it’s our cutting-edge internet money and payments backbone for both internal company operations, and inside our suite of Web3 infrastructure products and services. Together with Circle, Gelato is working on novel, seamless ways to use USDC as the payment rails for transaction gas fees, removing one of the biggest barriers to Web3’s mainstream adoptions.” – Luis Schliesske, Co-founder of Gelato.


An Introduction to Gelato

I am Luis Schliesske, one of the co-founders of Gelato, here to share our journey with you. Gelato is a Web3 Cloud Platform that empowers Web3 industry leaders and Fortune 500 companies to launch their blockchains and smart contracts, all while delivering a feature-rich Web2 user experience, with Circle’s USDC serving as the backbone for payments.

Gelato was co-founded by Hilmar Orth and I with a strong vision to enable developers to build decentralized applications that can spearhead the widespread adoption of Blockchain technology. Since our initial protocol launch back in 2019, Gelato has fostered successful collaborations with industry-leading projects like Optimism, Aave, MakerDAO and many more, playing a pivotal role in powering core protocol functionality with features such as gasless transactions, VRF, and cloud functions for over 450+ dApps and counting.

Recently, Gelato made a significant leap into blockspace by introducing the industry’s first augmented Ethereum Rollup-as-a-Service Platform (RaaS) with first chains being built on top of it today. This new platform is a turnkey blockchain deployment solution of optimistic and zero-knowledge L2 chains with cutting-edge Web2 UX and seamless integration with favorite Web3 tools & services.

At Gelato our longstanding commitment is to lower the entry barriers for Web3 developers, making it easy for anyone to create new, feature-rich blockchains and applications. We aim to provide a scalable and user-friendly experience, paving the way for a more decentralized and inclusive digital future.


USDC & Gelato

USDC plays a foundational role within the Gelato platform. As a trusted and widely used digital dollar, USDC is the stablecoin infrastructure powering several services on the Gelato platform.

Gelato has integrated Circle’s products to power its core services: Web3 Functions, Relay, and Automate. Circle’s USDC and Cross-Chain Transfer Protocol are supporting Gelato’s developer ecosystem with the tools to simplify payments and create seamless experiences for their end users. 

Gelato’s 1Balance and USDC

Gelato 1Balance is a unified multi-chain payment system that streamlines transactions across Gelato’s diverse services. This system offers an easy-to-manage balance, making it simple to cover all transaction costs across supported networks.

1Balance simplifies the complexities of multi-chain operations for more efficient cost management. Incorporating USDC deposits enhances the effectiveness of 1Balance, providing a reliable store of value, shielding users from the volatility commonly associated with digital currencies. USDC deposits on Polygon PoS covers costs across different networks while using Gelato services, ensuring an efficient and user-friendly experience across the platform.


Gelato 1Balance stands out as a uniquely designed payment system, providing an optimal solution for customers navigating cross-chain relay transactions. Users deposit USDC into their 1Balance on the Polygon PoS network. This singular balance covers relay costs across all chains, irrespective of the target chain. This service is incorporated into sponsoredCall and sponsoredCallERC2771 requests, where the developer sponsors the costs for their dApp users through the 1Balance system.

The convenience of this process, along with its comprehensive coverage, positions Gelato 1Balance as a transformative tool in the multi-chain landscape. The inclusion of USDC adds to the convenience and robustness of this process, providing developers with a stable and widely accepted cryptocurrency, and reducing friction and complexity in transactions.


Gasless Cross-Chain Transfers with Gelato + CCTP

Circle’s Cross-Chain Transfer Protocol (CCTP) enables USDC transfers securely between supported blockchains via a native burn-and-mint process. The process involves burning a quantity of USDC on a source chain, an attestation by Circle’s automated service to validate the authenticity of the burn, and minting the same quantity of USDC on a destination chain. With no need for lock-and-mint bridging or liquidity pools on either side of the cross-chain transfer, CCTP provides a highly secure and capital-efficient way to move USDC from one chain to another.

The challenge is that all on-chain transactions require network tokens (e.g. ETH on Ethereum, or AVAX on Avalanche) to pay for network gas fees on the source and destination chain. CCTP transfers are no different since there is an on-chain transaction involved to burn and mint USDC. For users, needing to hold a separate network token to pay for gas fees is cumbersome and presents friction in the process, especially for mainstream audiences.

To remove this obstacle, Gelato has integrated CCTP into its Web3 Functions and Relay developer tools, providing an automated way to enable users to pay cross-chain gas fees with USDC. This means a user can now easily access a CCTP-powered app and make a cross-chain transaction with USDC without ever needing to hold ETH, AVAX, or other network tokens.

Here’s how it works:

  1. A user initiates a request to an app to transfer USDC across chains.
  2. The transaction is relayed by Gelato Relay to burn USDC on the source chain via CCTP and pay the gas fee in USDC.
  3. The burn event is observed by Circle’s attestation service and a Gelato Web3 Function fetches the attestation automatically.
  4. The Web3 Function relays the final transaction on the destination chain using the attestation to mint USDC via CCTP for the user and pays the gas fee in USDC.

Developers can start their journey by exploring Gelato’s Gasless CCTP Github repo and Circle’s guide to CCTP. The combination of Gelato and CCTP paves the way for innovative multi-chain apps that can reshape the user experience for USDC and unlock more mainstream use cases.

We are thrilled to partner with Circle and enable Gelato’s Gasless CCTP SDK to pave the way for seamless blockchain interoperability with secure, gas token-agnostic asset transfer. By leveraging Gelato Relay and Web3 Functions, USDC serves  as a universal payment solution to abstract away the complexity of multi-chain infrastructure and unite ecosystems.

Gelato’s Gasless CCTP SDK is expected to launch on Arbitrum, Avalanche, OP Mainnet, and many other EVM-compatible chains later this year. Documentation is coming soon. Join the conversation at


Web3 Services October Updates

Blog_w3s-octoberBuild faster and better on the blockchain with new Web3 Services tooling and learning resources introduced in October. Interactive quickstart guides will help you or your team quickly explore user-controlled wallets, Smart Contract Platform, CCTP and more, while Gas Station removes Web3 complexities for your users – helping you to deliver a seamless UX. Read on for the latest Web3 Services updates.

New additions

Sponsor your users’ gas fees with Gas Station

Together with Programmable Wallets, you can deploy Web3 wallets and deliver gas-free transaction experiences. Gas Station abstracts away the complexities of gas fees for developers and end-users:

  • For Developers: Developers can sponsor gas fees on behalf of users by setting up the Gas Station with a few clicks. Fees can be subsidized with fiat payment via credit cards, so that the responsibility of sourcing and holding native tokens is removed from developers. Read our dev docs here.
  • For End-users: Users no longer need to go through hoops to source native tokens to interact with Web3 apps, removing one of the biggest frictions of transacting on-chain.

Uptime Metrics

Stay up-to-date on Web3 Services’ system health! Circle’s uptime metrics dashboard now includes the operational status of various Web3 Services APIs, including: Configurations, User-controlled wallets, Developer-controlled wallets, and Smart Contract Platform APIs, plus Developer Console status.

[Reminder] We’d like to remind accounts that have upgraded from testnet to mainnet that the Free Trial offered for Web3 Services’ launch period has now concluded. Please check your Billing configuration to ensure that your payment information is up-to-date.


Learn and build with Circle

We’re excited to share a series of learning resources– interactive quickstarts, blogs, and video walkthroughs–that will guide you through creating your first wallets and initiating transactions with Web3 Services:


Kickstart your development journey with our new Interactive Quickstart on user-controlled wallets! User-controlled wallets provide your app’s users with the highest level of control over their transactions and assets by setting a unique PIN code as the authorization mechanism.

In under 60 minutes, this step-by-step guide can help you through the process of creating users, setting up wallets, and initiating a transaction–all with only a few lines of code. Walk away from this quickstart with executable code that you can take with you to deploy in your own environment!



Start building your Web3 app that enables secure, efficient, and native USDC transfers across blockchains by integrating three of Circle’s offerings: Smart Contract Platform, Programmable Wallets, and the Cross-Chain Transfer Protocol.

This interactive quickstart will guide you through initiating a USDC transfer using CCTP from Ethereum (Goerli Testnet) to Avalanche (Fuji Testnet) using a Programmable Wallet. Leveraging these building blocks will help you create a blockchain-agnostic experience that enhances USDC liquidity and flexibility, and provides a frictionless UX for your app. Start building now!



Introducing the Future of Wallet Management with Developer-Controlled Wallets

Circle Engineer, Tobias Golbs, discusses the release of Circle’s new Developer learning portal. The first release focuses on “Introducing the Future of Wallet Management with Developer-controlled Wallets.”

Interactive Quickstart Guide for Circle’s Developer-Controlled Programmable Wallets

Senior Developer Relations Specialist, Blessing Adesiji, walks through Circle’s interactive guide, which allows developers with minimum Web3 experience to explorethe steps to deploy and transact with their first developer-controlled wallet using Circle’s Web3 Services.

Leveraging Circle’s Programmable Wallets for creating your first wallet and initiating your first transaction

Circle Product lead, Ian Lin, walks through User-Controlled Programmable Wallets, which includes how to configure and deploy your first wallet across multiple blockchains and make an initial transaction.


Live workshops

Follow us on Discord and join us for our live workshops!


Programmable Wallets and Smart Contract Platform application programming interfaces (“API”) are offered by Circle Technology Services, LLC (“CTS”). CTS is not a regulated financial services company and the APIs do not include financial, investment, tax, legal, regulatory, accounting, business, or other advice. For additional details, please click here to see the Circle Developer terms of service.

Redefining USDC Access in Asia Pacific: Circle Mint in Singapore

At Circle, we have always been committed to pushing the boundaries of what is possible in the world of digital currencies. Today, we mark a pivotal step towards enhancing the accessibility and utility of digital currencies in Asia Pacific — Circle Mint is now available in Singapore.


A Closer Look at Circle Mint in Singapore

Following Circle Singapore’s receipt of a Major Payments Institution (MPI) license from the Monetary Authority of Singapore (MAS) in June 2023, we are proud to introduce Circle Mint under our MPI license in Singapore.

Circle Mint in Singapore adheres to MAS regulations, with a goal of ensuring compliance and reliability for our customers in Singapore and serving as a trusted gateway to the world of digital currencies. 

With Circle Mint in Singapore, customers with Singapore-registered entities can expect a host of benefits including:

  • No minting fees
    With zero fees to mint or redeem USDC, Circle Mint in Singapore cuts out the added risk, extra fees and long transaction times associated with brokers and resellers.
  • Instant Availability
    Fiat funds from a user’s bank account can be converted instantly and automatically to USDC (depending on the participating banks’ instant settlement networks). In the future, Circle Mint in Singapore will offer expanded access to regional banking rails for near-instant settlement, allowing customers to conduct transactions with ease.
  • Compliance to MAS Regulations
    Circle Mint in Singapore is tailored to align seamlessly with MAS’ regulations, ensuring financial activities are both efficient and secure.

As digital currencies are gaining ground within Asia Pacific, Circle Mint Singapore makes digital currencies more accessible for businesses in the region.

Stay tuned for more updates as we continue to share the future of finance! 

About Circle Internet Singapore Pte. Ltd.

Circle Internet Singapore Pte. Ltd. (Circle Singapore) is an affiliate of Circle Internet Financial, LLC (Circle) based and incorporated in Singapore. Circle Singapore is licensed to provide digital payment token services, cross-border money transfer services, and domestic money transfer services under the Payments Services Act 2019, as amended.

About Circle Mint

Circle Mint and money transmission services are provided by Circle Internet Financial, LLC. Circle Internet Financial, LLC, NMLS # 1201441, is a licensed provider of money transmission services. A full list of Circle’s licenses can be found here.

Circle is not a bank; Circle Mint is not a bank account, and any funds are not insured by the Federal Deposit Insurance Corporation, the Securities Investor Protection Corporation or by any US or foreign government agency, insurance fund, person or entity.



Circle Research Releases ‘Robust Thresholds ECDSA Signatures’ Whitepaper to Identify Misbehaving Signers in Real-Time

TL;DR: Circle Research has improved blockchain transaction security by combining the CGG+21 signing protocol with the CGG+21 traitor tracing protocol. This lets 3rd party observers identify malicious signers in real time – helping to mitigate malicious attacks. 

  • Circle Research releases open-source Golang implementation of CGG+21 threshold signatures to support Web3 developers.
  • The CGG+21 signing algorithm is the recommended update to GG18. Users of the popular Binance tss-lib GG18 library can switch to the Circle Research cggplus signing module while keeping their existing keys.
  • CGG+21 requires fewer rounds of communication than GG18 making it faster for cold storage scenarios.

Securing Transaction Signatures

High-stakes blockchain transactions often require multiple parties to cosign. While many newer blockchains support multiple signers for a single transaction with a native multi-signature feature, this is not the case for some older and more established blockchains such as Ethereum. Threshold signatures are an off-chain workaround utilized when multi-signatures are not available on-chain. In this approach, multiple participants divide the signing key associated with a single address off-chain. This makes multi-sig available to Web3 developers regardless of the underlying blockchain. Threshold signatures offer the added advantage of protecting signer privacy. Since they look like ordinary signatures, viewers cannot ascertain who signed the transaction or even how many signers there were, thereby upholding a fundamental tenet of Web3 – the protection of user privacy. Threshold signatures also cost less gas to verify than native multi- signatures or multi-signature smart contracts.


Security Upgrade

The widely used GG18 protocol has been found to have many security flaws. Library developers have been working hard to keep up with each new vulnerability fix. The authors of GG18 recommend that developers switch to CGG+21 as it solves many of the underlying issues. Circle Research is excited to release an implementation of CGG+21 in the programming language Golang. To our knowledge, this is the first open source Golang implementation of CGG+21. We integrated our implementation into the widely used Binance tss-lib GG18 library. Importantly, existing tss-lib deployments can continue using the same keys and just upgrade the signing software to use the Circle Research cggplus module instead of the original signing module. 


Detect Misbehavior in Real-Time

CGG+21 detects malevolent signers in real-time. Circle Research has chosen to move the zero-knowledge proofs of correct behavior from the traitor-tracing rounds into the main protocol. The total number of rounds is the same, but the messages are now longer. This change enables signers and even a 3rd party observer to detect misbehavior right away and identify the culprit, therefore improving overall security of blockchain transactions.


Optimized for Cold Storage

The most expensive step for signing transactions where keys are in cold storage is to actually go into the vault to access the offline key. CGG+21 requires only 4 rounds of communication, the first three of which are pre-computations that can be prepared in bulk in advance. Signers need to make only a single visit to the vault to actually sign the transaction.  Using CGG+21 allows cold storage users to significantly lower their signing times by reducing vault visits from 5 to 1.

We invite users of tss-lib to try the new cggplus module here:

Researchers and developers can look at our whitepaper with the technical details here

Announcing: USDC v2.2

We’re excited to unveil a new v2.2 upgrade to USDC and EURC that significantly reduces gas costs, improves support for account abstraction, and further bolsters security for transactions on EVM blockchains. The upgrade adds to the momentum of USDC innovation after its recent expansion to 6 new blockchain networks.

As USDC and EURC represent the intersection of money and code, their capabilities will continue to evolve as new opportunities arise to add new features and refine existing ones.  We’ve developed a number of enhancements for v2.2 since the last upgrade to USDC in early 2021.

There will be six new changes to the USDC and EURC smart contracts and they’ll be implemented through a single v2.2 upgrade for each supported EVM blockchain. The upgrade is fully backwards-compatible, does not introduce any breaking changes to existing integrations, and requires no action from developers or users. All code changes have been audited by Halborn, a leading third-party blockchain security firm.1

Here are the details on the improvements we’re making:


Enable signature validation from smart contract wallets

USDC and EURC will adopt EIP-1271 to allow authorized transfers to be used from a smart contract wallet in addition to a private key wallet. EIP-1271 has been adopted by over 50 protocols and products to date2, including significant market participants like Uniswap.3

This new change improves USDC and EURC support for account abstraction, a rapidly growing initiative in the EVM ecosystem to usher in simplified user experiences for mainstream audiences.

Importantly, this enables developers to build products that allow users to pay network gas fees in USDC and EURC, as a smart contract wallet can act as a relayer in permit, transferWithAuthorization, receiveWithAuthorization, and cancelAuthorization function calls.


Improve efficiency of blocklisting check

The blocklisting feature of the USDC and EURC smart contracts allows Circle to prevent specific addresses from sending and receiving USDC and EURC. The process for using the blocklist remains unchanged and follows Circle’s Access Denial policy (see USDC Terms and EURC Terms).

Most user operations, like transferring USDC between accounts, will require checking the blocklist prior to execution. The need for additional computation results in increased network gas fees compared to a base ERC-20 implementation.

With v2.2, we’ve optimized how the blocklist state is stored for USDC and EURC to yield a more efficient lookup process. The result is a significant reduction of network gas fees for transfer, transferFrom, transferWithAuthorization, receiveWithAuthorization, burn, and mint function calls.

Cost reduction can range between 6-7% for functions invoked in many common use cases, such as making a transfer, payment, or trade with USDC or EURC. Developers and users of Cross-Chain Transfer Protocol (CCTP) can also see a 3-4% reduction in network gas fees when burning and minting USDC across blockchains.



Avg # gas change per txn

Avg % gas change per txn

Avg $ gas change per txn

















Source: Cost estimates calculated via simulations run by Circle.

Assumptions: Ethereum blockchain, gas price of 20 Gwei, and ETH price of $1,700.


Improve resiliency against forks

The open nature of public blockchains enables the developer community to create copies, or forks, of a given network at any time. For example, after the Ethereum merge event in late 2022, developers generated a fork of the Ethereum PoS blockchain to create and operate the Ethereum PoW blockchain. In this case, Circle officially supports Ethereum PoS for USDC and EURC native issuance, which means only USDC and EURC held on Ethereum PoS can be redeemed 1:1 for US dollars and euro, respectively.

To protect users from a misuse of funds that could result from future forks of Ethereum and other supported EVM blockchains, we’re implementing a change on the USDC and EURC smart contracts that will now dynamically infer the official chainID instead of setting it manually.

This means if or when an EVM blockchain is forked in the future, validators will be able to automatically verify the official chainID to prevent USDC or EURC transactions from being validated on unofficial forks.


Remove blocklist check from functions that don’t move funds

The checking of the blocklist occurs predominantly when USDC or EURC is being transferred. However, the v2.1 implementation also prevents the following actions for blocked addresses:

  1. Approving an amount for a future “pull-based” transfer (approve)
  2. Increasing the approved amount (increaseAllowance)
  3. Decreasing the approved amount (decreaseAllowance)
  4. A variation of approve (permitthat does not require gas

These functions do not move funds, but merely allow for funds to move in the future, which means a blocklist check during this operation is not relevant or useful. When an approval is leveraged in the future to move funds, the blocklist will always be checked at that time and will prevent the movement of funds as applicable.

With this change, we are removing the blocklist check on functions that don’t move funds, resulting in a further reduction of network gas fees when using USDC and EURC. We’ve calculated an estimated ~7.34% gas savings for approve, ~3.5% for increaseAllowance and decreaseAllowance, and ~0.85% for permit.


Skip timestamp check when deadline is set to maximum amount

In order for USDC and EURC to comply with ERC-4337 and support account abstraction, certain commonly used operations such as checking the current timestamp cannot be run in function calls.

To allow the permit function to be 4337-compatible, we’ve taken a recommendation from the Ethereum community to implement permit in a way that avoids the timestamp check in some instances: “The deadline argument can be set to uint(-1) to create permits that effectively never expire.”

This change means that when permit is called with a deadline of uint(-1), which is the maximum value possible, we interpret that as having no expiry, so the timestamp check is skipped and the operation is compliant with ERC-4337. This approach is sound because it corresponds to a deadline that is several magnitudes larger than billions of years into the future.


One-time rename for EURC token symbol

We’ve recently streamlined our product naming construct and corresponding symbols to improve consistency and eliminate confusion when referring to Circle’s stablecoins:

  • USDC (pronounced U-S-D-C) is the official name and symbol for Circle’s dollar-backed stablecoin.
  • EURC (pronounced E-U-R-C) is the official name and symbol for Circle’s euro-backed stablecoin.

To match these naming improvements in the contract code, we’re adding a one-time option during the v2.2 upgrade to rename the token symbol for EURC from “EUROC” to “EURC”.

This change will only happen once as part of this upgrade and will not expose a public function to change the token name or token symbol in the future.


Rollout timing

Starting today, we’ll begin a phased rollout of the v2.2 upgrade to USDC and EURC on testnet and mainnet for each supported blockchain, which we plan to complete over the next few months. These upgrades will take place behind the scenes with no downtime, which means no action is needed from developers or users.


Planned rollout schedule:

  • Today (11/9/23)
  • Mid-November 2023
  • Late-November through December 2023
    • Arbitrum Goerli testnet and Arbitrum mainnet
    • OP Goerli testnet and OP Mainnet
    • Base Goerli testnet and Base mainnet
    • Polygon PoS Mumbai testnet and Polygon PoS mainnet
  • January 2024
    • Ethereum Goerli testnet and Ethereum mainnet
    • TRON Shasta testnet and TRON mainnet

Note: We’re planning to bring v2.2 to USDC and EURC on Sepolia testnet for supported EVM blockchains starting in January 2024.


One global community

USDC v2.2 is the culmination of research conducted by Circle and the broader developer community, who often contribute new ideas and enhancements via PRs to our public repo. Thank you to Alex Kroeger for suggesting gas efficiency improvements and to the many external contributors who have put time and effort into helping make USDC and EURC the most accessible and efficient money protocols on the internet.

If you have questions about the v2.2 upgrade or want to get started building with USDC and EURC, join the conversation in our Discord.


1. Circle contracted with Halborn, a third-party blockchain security firm to perform a code audit on the changeset for USDC v2.2.
2. – Last accessed 11/4/2023
3. Uniswap’s public repo – Last accessed 11/4/2023

Speculative Trading with Stablecoins Falls 90% as Payments Use Expands

The use of stablecoins for speculative trading in cryptocurrency markets has experienced a consistent, steep decline over the past five years. That’s the key takeaway of “Beyond Speculation: Payment Stablecoins for Real-time Gross Settlements,” a paper that was among the four winning research projects featured at DC Fintech Week 2023.


Led by Circle Chief Economist Gordon Y. Liao, the paper provides empirical evidence that demonstrates how the use of stablecoins for speculative activities in digital assets markets has plunged 90 percent since 2019, a trend that is also unrelated to market frenzies. 


While stablecoins started out as blockchain-based cash balances for crypto exchanges and traders, they have evolved over the past few years to resemble a form of general-purpose money tokenized on public blockchains, the paper said. The features that distinguish payment stablecoins, like USDC, from other varieties of stablecoins are twofold: their primary use as a general purpose form of payment, and full-reserve backing by high-quality, liquid assets. 


As payment stablecoins have shifted away from speculative activities, they continue to gain traction as a utility for real-world value transfers such as cross-border payments, emergency and humanitarian relief, and remittances.


Beyond Speculation: Key Findings

  • The use of stablecoins for speculative trading has declined 90 percent over the past five years. USDC, a payment stablecoin, has always had proportionally less trading activities as it was designed for general payments.
  • Payment stablecoins have emerged as a medium exchange and store of value with less speculative and leveraged activities than fiat M2 money. Payment stablecoin’s trading turnover is 10% that of trading stablecoins and 60% that of fiat M2 dollar.
  • The adoption of payment stablecoins for general use in real-time gross settlement could potentially mitigate risks associated with concentration and liquidity in the current payment systems. 
  • Greater integration of payment stablecoins with the existing financial infrastructure could bolster the capabilities of real-time settlement systems, making them more programmable, transparent and accessible.
  • This integration could also alleviate risks associated with concentration and liquidity in the current payment systems. 

The full text of the research paper is available here. A video summary is available here.

Native USDC now available on Polygon PoS

Polygon PoS USDC is now live! We’re announcing that USDC is available natively on Polygon PoS and accessible to developers and users – no bridging required. Circle Mint and Circle APIs now fully support Polygon PoS USDC, making it easy to access USDC liquidity and benefit from Polygon PoS’ fast and efficient network.


About Polygon PoS

Polygon PoS is a scalable proof-of-stake (PoS) blockchain that complements Ethereum’s decentralized security with faster settlement times and greater cost efficiency.Businesses and developers can create applications with USDC on Polygon PoS that appeal to the general public and benefit from near-instant, near-zero cost transactions worldwide.1 

As of October 2023, the Polygon PoS ecosystem includes 475+ dApps and over 300,000 active wallet addresses.2 Businesses and developers interested in designing for mainstream user experiences can now choose Polygon PoS USDC for payments, remittances, trading, borrowing, lending and more.


Understanding native vs. bridged

Circle brings USDC natively to new blockchain networks to empower developers to build on a stable foundation they can trust. Native USDC is officially issued by Circle and is always redeemable 1:1 for US dollars.

In the case of Polygon PoS, there also exists a “bridged” form of USDC known as USDC.e, which is USDC that has been bridged from Ethereum. Bridged USDC (USDC.e) is not issued by Circle.


Bridged USDC from Ethereum


Native USDC issued by Circle

On November 10th, Circle will discontinue support of deposits and withdrawals for bridged USDC.e on Polygon PoS for Circle Mint and its APIs, including Express. After that time, only native USDC will be supported moving forward.

This means after November 10th, you should not attempt to send bridged USDC.e to your Circle Mint account, as it may not be recoverable and could result in a loss of funds.

To learn more about the discontinuation of support for bridged USDC.e in Circle Mint and its APIs, please see our Help Center article.


Powering new use cases

Exchanges, digital wallets, institutional traders, and developers can access Polygon PoS USDC via Circle Mint and Circle APIs for a number of use cases:


  • Making low-cost payments and remittances globally that can settle in seconds
  • 24/7 trading, borrowing, and lending on apps like Aave, Uniswap, and Quickswap
  • Enable users to hold savings in digital dollars without needing a traditional bank account

Get started today

Businesses can readily access on/off-ramps for converting fiat currency to Polygon PoS USDC by applying for Circle Mint.

Developers can start building with Polygon PoS USDC with our developer docs – USDC is an open-source, permissionless protocol that anyone can build on.

1  (Last accessed October 2, 2023)

2 (Last accessed October 2, 2023)

How Huma Finance uses USDC for their global financing platform

Huma Finance is the leading on-chain private credit ecosystem, where real world businesses bring their high-performing receivables to connect with global capital.

Despite interest in harnessing the benefits of blockchain technology, many companies, including fintechs around the world, lack the resources to build blockchain compatible solutions. Everyday businesses often lack access to crypto assets, and bringing cash flow driven financing markets onto blockchain is technically complicated.

Huma Finance aims to address these issues by providing infrastructure for fintechs and other on-chain lending protocols to enable global lending solutions.

We’re building an ecosystem where financing opportunities are within reach for businesses, helping form the foundation for a network of real-world lending solutions. Huma provides services for a diverse set of partners, including on-chain remittance financing, supply chain financing, inventory financing, green financing, and other credit ecosystems that narrow traditional financing gaps and provide greater economic opportunity around the world.

Huma Finance Founding Story

It was May 2014. I was one of the mentors at the Thiel Fellowship program when a riveting pitch about ‘The Android of decentralized applications called Ethereum’ landed in my inbox from a kid I’ve never heard of before, Vitalik Buterin. His vision was bold and clear; Vitalik wanted to rebuild the internet from scratch, with decentralization and programmable money at the center of it. It was hard not to be impressed by his vision, but I thought the plan lacked the key elements of scale – accessibility, affordability, and efficiency. 

A few years later, I spoke with Circle executives while I was leading a top-notch fintech team at EarnIn, and was all too familiar with the limitations of financial infrastructures and services. Stablecoins were clearly one of the best applications of blockchain and could have a massive impact globally, delivering better and cheaper financial services 24/7, especially to those most in need. I mentioned this conversation to a few of my brightest colleagues, and the idea for Huma Finance was born!

While our initial thoughts centered around crafting decentralized financial solutions for the blockchain-savvy, similar to the initial pitch about Ethereum, that did not satisfy the key elements of scale. To truly revolutionize credit ecosystems worldwide, we needed to engineer a powerful platform, enabling fintechs to put superior solutions into action without the intricate knowledge of blockchains. The ease of use would democratize the benefits of blockchain and make it available to anyone.

Months of perseverance culminated in the debut of Huma as a pioneering credit platform where high-performing receivables, tokenized on-chain, meet with global capital. During our beta launch at ETHDenver 2023, more than 20 applications were built on the platform, and the surging demand for our solutions since then tells us we’re on the right path.

Being at the infrastructure layer of such a critical service puts a lot of responsibility on our shoulders. We need to have the highest standards of fairness, transparency, and auditability to ensure more businesses and people can access secure, trustworthy and affordable financial services daily a key reason we decided to work alongside Circle to bring our mission to life.

The benefits of working with Circle and USDC

While many platforms integrate with USDC, it’s how we leverage its strengths that sets Huma apart. With USDC, our partners can trust in the stability and accuracy of transactions. This isn’t just about using a stablecoin; it’s about ensuring that every party involved – whether lending or borrowing – can do so with absolute confidence.

USDC offers a sound measure of value, crucial in receivables-backed financing models. The stability and security of USDC help ensure the valuation of the collateral remains consistent, allowing for predictable and secure transactions. 

The established USDC ecosystem makes it a comfortable choice for both lenders and borrowers, offering a familiar on- and off-ramp for transactions. 

A trusted digital dollar is essential for lending activity in a digital economy. Huma, as a leading on-chain credit ecosystem, has adopted a conservative, strategic approach that only uses stablecoins that operate under the highest standard. Huma has full trust in USDC because of the simplicity of the reserve model (always redeemable 1:1 for U.S. dollars), third-party attestations, transparency, utility and mutual respect with the Circle team.

Huma x USDC in action

To me, these aren’t just partnerships. They’re testimonies to what Huma and USDC bring to the table – a unique amalgamation of technical prowess and a deep understanding of real-world challenges.


Huma Partner Spotlight: and Huma Finance partnered to offer blockchain-enabled lending services to small businesses in emerging markets through the use of USDC. This collaboration aims to broaden financial opportunities by building on Huma’s infrastructure to reduce the cost of service and foster a more equitable economic landscape. Remarkably, Jia’s integration was swift — fully operational within weeks. They secured the needed liquidity on-chain in a matter of days, and have been on an upward trajectory since.

Because Jia uses USDC on the Huma platform, their customers get greater transparency into contributions to lending pools, distributions, payments, interest disbursements and more. Furthermore, the partnership exemplifies the potential of leveraging technological advancements in reshaping financial systems. The combination of Huma’s blockchain technology and Jia’s innovative lending solutions offers enhanced access to capital for diverse businesses, from medical establishments to local school supplies and food vendors. By doing so, they are not only facilitating business growth, but also contributing to the economic development of these communities.


Huma Partner Spotlight:*

Cross-border payments, despite their centrality to global finance and the livelihood of immigrant families, continue to be an expensive and painful experience. Remittance companies trying to innovate and build a more affordable solution face a plethora of challenges, such as the necessity for managing numerous pre-funded accounts around the world for timely settlement. This has resulted in trillions of dollars held in pre-funded accounts, representing a significant overhead for the global payments industry that operates on thin margins. To completely remove the need for prefunding accounts, and deliver capital instantly across the world, Arf partnered with Huma Finance, and introduced an on-chain liquidity solution for cross-border payments.

Arf’s approach provides on-demand USDC-based working capital loans to financial institutions facilitating these remittances. Moving away from the archaic pre-funding approach, this model uses real-time USDC settlements for cross-border transactions. By utilizing Huma’s infrastructure, Arf enhances transaction speed and volume, simultaneously promoting transparency in the sector.

This is achieved by tokenizing cross-border payment orders through Huma, which then serves as collateral to borrow against. Consequently, every transaction, including loans, repayments, and receivables, is trackable on the blockchain. These records incorporate auditable financial details in a privacy preserving manner that can be verified by global audit firms, providing a level of insight that did not exist before.

*Circle Ventures, an affiliate of Circle Internet Financial, LLC, has invested in Arf

Looking Ahead

Huma’s horizon is ever expanding. With plans to tokenize more types of receivables in sectors like green financing, credit cards, cross-border settlements, invoice financing, royalty payments, and others, we are aiming to improve the accessibility, affordability, and efficiency of financial services.

Our growing ecosystem is taking a critical role in delivering these solutions collectivelyacross the globe, while innovating on every aspect of service quality.

If you are building innovative credit solutions, and seek a partner with deep expertise in multiple domains, please reach out. Together, we can create a financial landscape where opportunities are increasingly accessible to all.

Huma Finance is a Circle Ventures portfolio company. Circle Ventures, an affiliate of Circle Internet Financial, LLC, has invested in Huma Finance.

Web3 Services September Updates

blog_W3S-septWe’re excited to share several updates we’ve deployed to help you build Web3 apps faster and better! Our updates include new features to manage and integrate smart contracts, security enhancements, and a new interactive guide to help kickstart your development journey. Read on to learn more about our updates.

New additions


Quickstart Guide
Start building your first developer-controlled wallet(s) with our Interactive Quickstart Guide! With only a few lines of code, generate an API Key, entity secret, and wallets, and execute transactions with just our step-by-step guide. Take away a sample code snippet that you can reuse for your project.


Deploy smart contracts

Supercharge your Programmable Wallets, and manage wallets and smart contracts using one console. Deploy and interact with smart contracts using Programmable Wallets for a streamlined experience on the blockchain. Access via UI or API to explore popular smart contracts, or simplify interactions with our code generation tool. Start interacting now.

Screenshot 2023-10-02 at 4.56.50 PM


Create restricted API keys

Create Restricted API Keys to strengthen your app’s security. Restricted API Keys allow you more granular control by setting access rights (read-only or write), or defining the scope of APIs they can access, like wallets, smart contracts, or webhooks.

Screenshot 2023-10-02 at 4.58.16 PM


Webhook event logs & tooling

Review webhook event logs and tooling to filter and sort through a record of webhook notifications and their corresponding triggered events. Leverage it to view detailed information like event data or troubleshoot unsuccessful webhook attempts by resending them manually.

Screenshot 2023-10-02 at 4.58.57 PM




We now require distinct entity secret ciphertexts for developer-controlled wallets API requests

Mitigate the risk of replay attacks with distinct entity secret ciphertexts for developer-controlled wallets API requests. This new requirement is to enhance the security of API requests like transaction requests and smart contract interactions. Follow our sample code for guidance on how to generate distinct entity secret ciphertexts.



Circle Account is now Circle Mint

At Circle, we’re focused on making access to programmable money smoother, simpler, and more convenient than ever before. Today, we’re thrilled to announce another milestone in our journey – Circle Account is getting a fresh new name – ‘Circle Mint.’


Why ‘Circle Mint’

This new name better reflects Circle Mint’s core feature – enabling enterprises and large scale USDC/EURC distributors to mint and redeem USDC and EURC directly from the source. This change will not impact account details, login credentials, or any ongoing transactions. Existing users can continue using their accounts without any disruption. You’ll continue to find the same trustworthiness, reliability, and excellence that you’ve come to expect from us – just under a new name. 

Circle Mint will continue to evolve into a powerful enterprise platform, building on its comprehensive range of features – which currently include granular user roles and permissions, authentication capabilities, and advanced reporting functionality. 


Global Access to Stablecoins

Access USDC and EURC worldwide

Circle’s USDC and EURC stablecoins are available to mint and redeem in 80+ countries.* Connect your existing bank account to fund your Circle Mint account with wire, SEPA, and banking network transfers. Send automatic transfers directly from your USDC balance back into your bank account. 

*Via wire transfer, SEPA and banking network transfers are limited to participating banks in limited regions.


User Permissions

Manage your funds securely 

Right-size user policies and configure them for your business account. Delegate financial tasks and approvals confidently with multi-user roles and granular permissions. Ensure complete transparency and maintain financial oversight of your account and all permissioned users. 



Send funds anytime, globally–and settle in just seconds

Expand and streamline your global business transactions with Circle’s near-instant settlement and low costs. Transfer funds seamlessly across blockchain networks 24/7 and approve transactions effortlessly with the Circle Authenticator App.



Connect using web UI or integrate with APIs

Mint Circle’s USDC and EURC stablecoins through the web console or integrate with our APIs to automate minting and redemption. Now you can provide stablecoin access directly to your users through your own app or website.



Circle Mint and money transmission services are provided by Circle Internet Financial, LLC. Circle Internet Financial, LLC, NMLS # 1201441, is a licensed provider of money transmission services. A full list of Circle’s licenses can be found here.

Circle is not a bank; Circle Mint is not a bank account, and any funds are not insured by the Federal Deposit Insurance Corporation, the Securities Investor Protection Corporation or by any US or foreign government agency, insurance fund, person or entity.

Circle Files Amicus Brief on Payment Stablecoins

Since Circle’s founding a decade ago, we have always aspired to a regulation-first approach based on trust, transparency, accountability and financial integrity. We believe it is essential to comply and communicate with governments and regulators on matters that impact our business and customers. To that end, Circle filed a friend-of-the-court, or amicus, legal brief in the U.S. District Court for the District of Columbia on Sept. 28 outlining why USDC and other U.S. dollar-backed payment stablecoins are not securities. The brief also explains that the U.S. Securities and Exchange Commission does not have jurisdiction over payment stablecoins, because USDC is a form of money and lacks the essential features of an investment contract.


The court is considering a case in which the SEC accuses Binance of illegally offering and selling BUSD as an “investment contract” and therefore a type of “security” under federal law—without registering it with the SEC. The case marks the first SEC enforcement action involving a dollar-denominated stablecoin. 


“Circle has a strong interest in advancing a robust, well-defined regulatory and legal framework for payment stablecoins and in ensuring that existing laws and regulations are enforced with both vigor and precision,” the brief said. “The SEC’s claim that Binance offered and sold its competing stablecoin as an unregistered security raises serious legal questions affecting digital currency and the U.S. economy more broadly.”


Circle submitted our brief not to support either party in the case, but to aid the court’s consideration of the SEC’s allegations about BUSD.  While Circle takes no position on whether the SEC has sufficiently alleged that Binance offered or sold a security, our brief makes three points:  


  • First, payment stablecoins—and especially U.S. dollar-backed payment stablecoins like USDC —are an essential part of the digital-asset ecosystem, and they are fundamentally different from the tokens that the SEC has previously asserted are securities. 
  • Second, standing alone, such payment stablecoins like USDC are neither investment contracts nor any other type of security, and so the SEC has no authority over standalone sales of these tokens.  In evaluating the SEC’s complaint, it is critical that the court assess the entire transactional context that the SEC alleges surrounded Binance’s sales of BUSD. 
  • Third, the legal and practical stakes at play underscore why the court should reject any overbroad or imprecise SEC assertions of jurisdiction over payment stablecoins. The court should be especially cautious before extending SEC enforcement authority over BUSD while stablecoins remain the subject of vigorous congressional debate and pending federal legislation.


Our brief notes that the SEC does not allege that BUSD, by itself, is a security – nor could it.  


“Payment stablecoins, on their own, do not have the essential features of an investment contract.  They do not independently give buyers any potential for profit, and certainly not based on the efforts of the stablecoin issuer,” the brief said.  “As a result, the SEC has no jurisdiction over such stablecoins, absent additional factors that turn the sale of the stablecoin into an investment contract.


We also urge the court to carefully scrutinize the SEC’s novel claims of authority to ensure that Binance’s BUSD offering in fact falls within the agency’s jurisdiction.


“[A]ny potential jurisdictional conflict created by this Court would undercut the activities of other federal and state regulators, private plaintiffs, and even Congress itself,” Circle said in its brief.  “More broadly, a novel grant of jurisdiction over payment stablecoins to the SEC by this Court would sow widespread confusion over a tool used to facilitate trillions of dollars in transactions each year and result in substantial detriment to the digital-asset industry and the U.S. economy at large.”


The full text of Circle’s amicus brief is available here.

What you need to know: Native USDC on Polygon PoS

Native USDC will launch on Polygon PoS on October 10th, which will kickoff a transition away from bridged USDC for ecosystem apps, developers, and users. This transition will also coincide with a discontinuation of support for deposits and withdrawals of bridged USDC via Circle Account and its APIs on November 10th.

Please read on for everything you need to know regarding timelines and FAQs for this transition.


Native to Polygon PoS

USDC issued by Circle will be native to Polygon PoS and will be the official form of USDC for the ecosystem. Over time, native USDC liquidity will grow and replace the bridged USDC liquidity that comes from Ethereum via the Polygon PoS Bridge.


Benefits of native USDC

  • Fully reserved and always redeemable 1:1 for US dollars
  • Supported by Circle Account and its APIs
  • Enables institutional on/off-ramps
  • Future support by #CCTP to eliminate bridge withdrawal delays

Understanding bridged vs. native

Ahead of the launch of native USDC, the Ethereum-bridged form of USDC on block explorers like PolygonScan will be renamed as USDC.e. There will also be outreach to ecosystem apps to make the same change in their app UI and documentation.


Bridged USDC from Ethereum

Token Symbol: USDC.e

Token Address: 0x2791bca1f2de4661ed88a30c99a7a9449aa84174 


Native USDC issued by Circle

Token Symbol: USDC

Token Address: 0x3c499c542cef5e3811e1192ce70d8cc03d5c3359


Circle Account and its APIs will only support native USDC

When native USDC on Polygon PoS launches on October 10th, Circle Account will support deposits and withdrawals for both native USDC and bridged USDC.e for 30 days.

On November 10th, Circle will discontinue support of deposits and withdrawals for bridged USDC.e on Polygon PoS for Circle Account and its APIs, including Express. After that time, only native USDC will be supported moving forward.

This means after November 10th, you should not attempt to send bridged USDC.e to your Circle Account, as it may not be recoverable and could result in a loss of funds.


Changes to Circle’s API Chain Codes

For Circle customers that utilize Circle Account and its APIs, you will need to adjust your API integration to work with native USDC on Polygon PoS moving forward.


Native USDC on Polygon PoS

Token Symbol: USDC

Token Address: 0x3c499c542cef5e3811e1192ce70d8cc03d5c3359

API Currency Code: USD

API Chain Code: POLY


Bridged USDC on Polygon PoS

Token Symbol: USDC.e

Token Address: 0x2791bca1f2de4661ed88a30c99a7a9449aa84174 

API Currency Code: USD

API Chain Code: MATIC


Please note that Circle APIs differentiate between native USDC on Polygon PoS and bridged USDC on Polygon PoS by utilizing different API Chain Codes. The API Currency Codes are the same.


Liquidity migration

Ecosystem developers will work to ensure a smooth transition from USDC.e to USDC on Polygon PoS over time. There will be no immediate changes to the Polygon PoS Bridge and it will continue to operate normally.

To improve the developer and user experience, Circle intends to bring Cross-Chain Transfer Protocol (CCTP) to Polygon PoS after the launch of native USDC. Upon integration into the Polygon PoS Bridge, this will enable USDC to move natively to and from Ethereum (and many other supported chains) in minutes – no more withdrawal delays.


Stay tuned for launch on October 10th

We’re very excited about what native USDC means for the Polygon PoS ecosystem! Please reach out to your Circle rep or via Discord if you have any questions. #StableSeptember is marching on into October…

USD Coin and Euro Coin are now exclusively: USDC and EURC

Circle is on a mission to raise global economic prosperity through the frictionless exchange of value. How you find and identify our stablecoin products should reflect the same ease and simplicity. 

Today, we are streamlining our product naming construct and corresponding symbols to improve consistency and eliminate confusion when referring to Circle’s stablecoins.

Here’s what’s new


USDC (pronounced U-S-D-C) is now the official name and symbol for Circle’s dollar-backed stablecoin. The name “USD Coin” is being phased out.

Note: The existing token addresses remain the same; we will not be introducing a separate token.


EURC (pronounced E-U-R-C) is now the official name and symbol for Circle’s euro-backed stablecoin. The name “Euro Coin” and symbol “EUROC” is being phased out.

Note: The existing token addresses remain the same; we will not be introducing a separate token. In the coming months, we will update the symbol on the existing token addresses to EURC.


All Circle-owned media and communications have been updated to reflect these changes, and we are now encouraging all of our customers and partners in refreshing their platforms to reflect the new names and logos by November 20, 2023.

Please visit the links below for complete branding guidelines and details.

USDC Brand Guidelines
EURC Brand Guidelines