Circle launches Arc mainnet to run fees and payments in USDC

Circle launched the Arc mainnet on Sept. 16, opening a public production network that uses a single USDC balance for payments and transaction fees. Arc is a layer-1 blockchain built to make USDC the asset used to pay both transfers and network fees.

Arc is Ethereum-compatible and targets transaction finality in under one second. The network allows developers to express both spending and fee requirements in USDC while using familiar Ethereum developer tools.

The project moved from a private mainnet that included more than 100 ecosystem and institutional builders into a public network after a public testnet opened on Oct. 28, 2025. Circle’s guidance for wallets instructs that native and token interfaces reflect the same underlying USDC holding to prevent double-counting funds.

Arc combines open access for application development with a permissioned validator set responsible for consensus. The announced founding validator cohort includes BlackRock, DTCC, Visa, Mastercard, Standard Chartered and other financial companies alongside Circle. The network separates permission to build applications, which is open, from permission to validate transactions, which is limited to selected institutions.

Arc’s documentation lists opt-in privacy features and Stablecoin Services as planned components that are not available at launch. Circle describes the design as supporting payment and settlement flows that use USDC to settle transactions and pay fees.

At the end of June, Circle reported about $73.3 billion of USDC in circulation. Tether reported approximately $184.6 billion of USDT for the same quarter. Moving existing USDC from other chains into Arc would change where on-chain activity occurs without changing the total supply of USDC.

The Arc mainnet entered public production on Sept. 16. Circle states the network is open for application development while validator slots remain with the selected founding institutions.