Circle Internet Group (NYSE: CRCL) has opened the public mainnet of Arc, an open Layer-1 blockchain the company positions as infrastructure for markets, fast settlement, and automated onchain activity. The network went live on September 16, 2026, after a private mainnet period and a public testnet that Circle said processed more than 700 million transactions in under a year.
Circle describes Arc as more than a general-purpose chain.
The company frames it as an “economic operating system” meant to support payments, foreign exchange, tokenized assets, lending, trading, and software agents that can move value with less human intervention.
At launch, Circle said more than 100 applications were available and more than 100 banks, asset managers, payment firms, exchanges, custodians, DeFi teams, wallet providers, and AI platforms were already building on the network.
A defining design choice is how users pay for computation.
Transaction fees are denominated in USDC rather than a volatile native coin, which Circle argues makes costs more predictable for institutions and payment applications.
USDC, Circle’s regulated dollar stablecoin, had more than $74 billion in circulation at the time of the announcement.
The chain is EVM-compatible, so Solidity contracts can be reused, and Circle says settlement is deterministic and reaches finality in under a second.
Security at launch is handled by a permissioned validator set. Circle will be joined in phases by a founding group that includes BlackRock, DTCC, Galaxy, ICE, Mastercard, MoneyGram, SBI Group, Standard Chartered, Sumitomo Corporation, Visa, and Worldpay, now part of Global Payments.
Circle presents that arrangement as a way to meet operational and compliance expectations of large financial firms while still allowing open application deployment.
Anyone can deploy software on public mainnet, even though block production starts with a curated validator cohort.
The launch also includes Circle’s broader product stack. Official materials point to interoperability with more than 20 chains through Circle CCTP and Gateway, tools for tokenized funds and programmable wrapped bitcoin, local-currency stablecoins, and the Circle Agent Stack for policy-controlled agent wallets.
Lending and trading protocols such as Aave, Morpho, and Uniswap were among the applications named as live from day one.
Circle has also previewed future “network sectors” aimed at confidential transactions, higher throughput payments, and verifiable agent activity, along with a possible move toward proof of stake in 2027.
This week Circle completed a genesis mint of 10 billion ARC tokens in the United States.
The company said that step makes it the first publicly traded firm to mint a network token for a new Layer-1 chain, but it also stressed that the mint is not a promise of a public token sale.
Network fees remain payable in USDC, and ARC is described as a coordination asset for future security, utility, and governance rather than the gas token at launch.
Chief executive Jeremy Allaire called Arc the company’s most important product debut since USDC, repeating Circle’s long-running claim that money should operate with the same openness and speed as the internet.
Whether that vision holds will depend on adoption by institutions already named as validators and by developers who now have a public chain on which to ship production applications.