What is Arc blockchain by Circle?

Arc is a layer 1 blockchain built by Circle, the company that issues the USDC stablecoin. It is designed for financial activity such as payments, currency exchange, lending and tokenized funds. Its public mainnet opened on September 16, 2026, and Arc's own site now says the network is live.

What is Circle Arc blockchain built for?

Arc's announcement describes it as an open layer 1 for stablecoin payments, FX, tokenized assets and payments made by AI agents. The network is launched by an entity called Arc Network Services LLC.

The design choices aim at businesses. Fees are paid in stablecoins, starting with USDC, so costs are quoted in dollars rather than a volatile coin. Arc's site promises deterministic finality in under a second. Its docs put finality below 350 milliseconds in benchmark tests. The Block reported that Arc is compatible with the Ethereum Virtual Machine, so existing Solidity contracts can run on it. An opt-in privacy feature for shielding transaction details is listed as coming later and was not live as of October 2026.

How do Arc testnet and Arc mainnet differ?

The public testnet launched in October 2025, and Circle said it handled more than 700 million transactions in under a year, The Block reported. A testnet uses tokens with no value. Arc's faucet hands out test USDC and EURC.

Before the public launch, Arc ran a private mainnet with more than 100 builders. The public mainnet arrived on September 16, 2026. Day-one apps included lending markets from Aave and Morpho and trading on Uniswap, and Circle said BlackRock planned to deploy its BUIDL fund on Arc. DTCC plans to tokenize assets held at its depository on Arc from the second half of 2027.

Who runs Arc, and what is the consensus model?

Arc is secured by a permissioned set of known operators, not open staking. Its docs describe proof of authority running on Malachite, an open-source version of the Tendermint protocol. Blocks are final once more than two-thirds of validators sign off.

Circle's August 2026 announcement named a founding validator cohort that includes Circle, BlackRock, DTCC, Galaxy, Global Payments, ICE, Mastercard, MoneyGram, SBI Group, Standard Chartered, Sumitomo Corporation and Visa. The Block reported they will join in phases, and that Circle is exploring a move to proof of stake in 2027. Visa's plans for Arc are covered in what is stablecoin settlement.

What is Arc crypto, the ARC token?

ARC is a token tied to the network, separate from USDC. The Block reported that Circle completed a genesis mint of 10 billion ARC during launch week. Circle called this a technical milestone, not a commitment to a public launch, and said ARC is meant to coordinate security, utility and governance. As of October 2026, gas is still paid in USDC.

Arc's own launch page notes that it has not been reviewed or approved by New York's financial regulator or any other regulator, and that features may change.