xReserve Supported Blockchains and Domains

xReserve operates across multiple blockchains. Each supported blockchain serves one or more of the following roles:

• Source chains where Circle-deployed xReserve smart contracts hold USDC reserves.
• Remote chains where USDC-backed tokens are issued.
• Destination chains where USDC or USDC-backed tokens are ultimately withdrawn.

The following tables list the mainnet and testnet blockchains where xReserve smart contracts have been deployed. Users deposit USDC into these contracts to receive an equal amount of USDC-backed tokens on remote blockchains.

Mainnet

Testnet

These are the destination blockchains where USDC or USDC-backed tokens are ultimately withdrawn:

• Gateway supported blockchains: Because xReserve holds USDC in Gateway wallets, users can withdraw USDC on any Gateway supported blockchain, including the source chain.
• CCTP supported blockchains: If a blockchain is not supported by Gateway, xReserve uses CCTP to forward the funds to another blockchain. This lets users withdraw USDC on any CCTP supported blockchain.
• Another remote blockchain: Users can burn USDC-backed tokens on one remote blockchain to withdraw USDC-backed tokens on a different remote blockchain.

A domain is a Circle-issued numeric identifier for a blockchain. xReserve uses domains in messages and attestations. Domains don't map to any existing public chain ID.

xReserve domains fall into two categories:

• Native domains are the blockchain on which USDC is held in an xReserve contract.
• Remote domains are the blockchain on which the USDC-backed token is deployed, minted, and circulated.