home /
Bridged USDC

Bridged USDC Standard

Bring bridged USDC to your blockchain

Circle’s specification and process for deploying bridged USDC on EVM blockchains enables optionality for a future upgrade to native issuance.1


import './FiatTokenV1.sol';

/** 
\* @title FiatTokenV2 \* 
@dev ERC20 Token backed by fiat reserves 
**/

contract FiatTokenV2 is FiatTokenV1 { 
    bool public newBool; 
    address public newAddress; 
    uint256 public newUint; 
    bool internal initializedV2;
    
    function initialize( 
    	string _name, 
        string _symbol, 
        string _currency, 
        uint8 _decimals, 
        address _masterMinter, 
        address _pauser, 
        address _blacklister, 
        address _owner, 
        bool _newBool, 
        address _newAddress, 
        uint256 _newUint ) 
     public {
    	super.initialize(_name, _symbol, _currency, _decimals, _masterMinter, _pauser, _blacklister, _owner);
        initV2(_newBool, _newAddress, _newUint);
    } 
    function initV2(bool _newBool, address _newAddress, uint256 _newUint) public { 
    	require(!initializedV2);
        newBool = _newBool; 
        newAddress = _newAddress; 
        newUint = _newUint; 
        initializedV2 = true;
    }
    ...

Benefits of the standard

Bridged USDC Standard empowers EVM blockchain and rollup teams to reduce liquidity fragmentation with a single form of bridged USDC that their ecosystem can build around.

Multichain

Permissionless & equitable

Teams, such as new L1 and L2 rollup teams or chain-sponsored third-party bridge deployers, can incorporate the standard to deploy a bridged USDC or EURC token contract. 

Smart Contract

Standardized & 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.2

Shield Check

Secure & 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.2

NFT

Upgradable & seamless

The upgrade to native USDC is performed in-place, giving developers and users immediate access to native USDC and avoiding any time-consuming migration.3

Multichain

Permissionless & equitable

Teams, such as new L1 and L2 rollup teams or chain-sponsored third-party bridge deployers, can incorporate the standard to deploy a bridged USDC or EURC token contract. 

Smart Contract

Standardized & 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.2

Shield Check

Secure & 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.2

NFT

Upgradable & seamless

The upgrade to native USDC is performed in-place, giving developers and users immediate access to native USDC and avoiding any time-consuming migration.3

Bridged to native

Bridged USDC plays a vital role in jumpstarting activity on new blockchain networks. Following the standard provides Circle with a path to upgrade to native USDC and enable deeper ecosystem interactions and opportunities.

Bridged USDC
 
Native USDC
Created by a third party
 
Issued by Circle, a regulated* fintech
Backed by USDC on another blockchain locked in a smart contract
 
Fully reserved and redeemable 1:1 for US dollars
Following the standard reduces the likelihood of liquidity fragmentation
 
"Official" form of USDC on a given blockchain
Not compatible with CCTP
 
Interoperable with multiple supported blockchain networks via CCTP

Benefits for the whole ecosystem

Bridged USDC Standard provides benefits for blockchains, developers, and users alike, catalyzing activity on new blockchain networks and simplifying any future transition to native USDC.

Chain

Blockchains

Get bridged USDC into the hands of developers and users early with the potential for a seamless upgrade to native issuance in the future, thereby avoiding the time-consuming liquidity migration process of educating and incentivizing your ecosystem to move from bridged to native USDC.

Code

Developers

Build on bridged USDC with a contract address that will persist after an upgrade to native, no code change needed. Provide users a way to store, pay, trade, borrow and lend with bridged USDC that automatically becomes native upon an upgrade. No need to swap to a new asset.

How it works

1.

Bridged USDC contract is deployed

Third-party team follows the standard to deploy their bridged USDC token contract.
2.

Initial liquidity enters the ecosystem

Bridged USDC is used to bootstrap initial liquidity in the ecosystem and begins to proliferate.
3.

High adoption of bridged USDC

Bridged USDC reaches a significant supply, amount of holders, and number of app integrations.
4.

Mutual agreement to upgrade to native

Circle and third-party team jointly elect to securely transfer ownership of the bridged USDC token contract to Circle.3
5.

Circle upgrades from bridged to native

Upon obtaining ownership, Circle upgrades bridged USDC to native USDC and seamlessly retains existing supply, holders, and app integrations.3
bridged-usdc-standard-howitworks-1
bridged-usdc-standard-howitworks-2
bridged-usdc-standard-howitworks-3
bridged-usdc-standard-howitworks-4
bridged-usdc-standard-howitworks-5
1.

Bridged USDC contract is deployed

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

bridged-usdc-standard-howitworks-1
2.

Initial liquidity enters the ecosystem

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

bridged-usdc-standard-howitworks-2
3.

High adoption of bridged USDC

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

bridged-usdc-standard-howitworks-3
4.

Mutual agreement to upgrade to native

Circle and third-party team jointly elect to securely transfer ownership of the bridged USDC token contract to Circle.3

bridged-usdc-standard-howitworks-4
5.

Circle upgrades from bridged to native

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

bridged-usdc-standard-howitworks-5

How to get started

If you're a new blockchain team or a third-party bridge deployer, dive into our implementation guide to learn how to deploy a bridged USDC contract that follows the standard today, or reach out to us on Discord.

View guide Join Discord

FAQ

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

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

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 Bridged USDC Standard.

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 to how Circle prioritizes native issuance for USDC.

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

  • 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 appchain and parachain is free to choose if they prefer to deploy a bridged USDC token contract.

In time, we intend to explore expanding 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).

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


You may provide Circle suggestions, comments, or other feedback (“Feedback”) with respect to Circle products or services. You agree that all Feedback is and shall be given entirely voluntarily and that Circle shall be free to use any Feedback provided to it, without obligation or restriction of any kind on account of intellectual property rights or otherwise.

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).

* See licenses here