What Arc is

Circle announced Arc as an open Layer 1 blockchain and describes it as an "Economic OS for the internet." Arc moved to public mainnet on September 16, 2026, after a private mainnet phase that Circle says included more than 100 ecosystem and institutional builders.

A Layer 1 blockchain is a base network that settles its own transactions, rather than relying on a separate blockchain for settlement the way a Layer 2 does. Arc is designed as a base network for financial activity, including payments, foreign exchange, tokenized real-world assets, and lending.

Arc is described as stablecoin-native, which means the network uses stablecoins to pay transaction fees rather than a separate, volatile token. A stablecoin is a digital token designed to hold a steady value, often tracking a currency such as the US dollar. The first stablecoin used for those fees is USDC, which Circle issues through its regulated affiliates.

How Arc works

Arc uses USDC to pay network fees, a cost often called gas. Because fees are denominated in USDC, Circle describes transaction costs as dollar-based and predictable, rather than tied to a token whose price can move sharply.

According to Circle, transactions on Arc settle in under a second. The network is secured by a founding group of validators. A validator is an operator that helps confirm transactions and add them to the blockchain. Arc's operating notice describes this as a permissioned validator set, which means the operators are approved by Circle rather than open to anyone.

Arc integrates directly with Circle's platform, including USDC and Circle's cross-chain infrastructure such as CCTP and Gateway, which are designed to connect USDC liquidity across blockchains. Circle says this lets Arc route liquidity and interoperate with other ecosystems, such as Ethereum and Solana.

Arc also describes opt-in privacy controls that let businesses selectively shield sensitive transaction details while preserving the ability to audit activity, which it says are designed to help meet regulatory and reporting obligations.

Why Arc matters for web3

Arc represents one approach to bringing stablecoins, payments, and real-world financial activity onto public blockchain infrastructure. Circle describes the network as purpose-built for financial flows, and its stablecoin-native design shapes how fees, settlement, and interoperability work.

Potential capabilities include:

• Predictable fees: Fees are paid in USDC, which Circle describes as producing dollar-based, predictable costs.
• Fast settlement: Circle says transactions settle in under a second.
• Interoperability: Circle's cross-chain infrastructure is designed to move USDC and connect Arc with other networks.
• Programmability: Developers can use smart contracts to build financial applications such as payments, FX, and lending.
• Compliance-oriented privacy: Arc describes opt-in privacy controls intended to support reporting and regulatory obligations.

These features also involve limitations and risks. Smart contracts can contain errors. Stablecoins and tokenized assets can depend on offchain issuers or custodians to maintain the connection between a token and what it represents. "Offchain" describes activity or records that exist outside a blockchain, and a custodian is an organization that holds or safeguards an asset for another party. The ability to transact on Arc depends on obtaining and holding USDC to pay fees. Because Arc uses a permissioned validator set, it is a separate system with its own operators and upgrade processes. Arc's documentation states that Arc has not been reviewed or approved by the New York State Department of Financial Services or any other regulatory authority. As with other financial infrastructure, availability may also vary by jurisdiction.

Arc and OpenSea

OpenSea added support for Arc on September 16, 2026, the same day as the network's public mainnet launch. Users can buy, sell, and swap supported Arc assets using OpenSea on web and OpenSea Mobile, alongside the other blockchains OpenSea supports.

OpenSea's Arc support covers more than one asset type. Users can swap tokens on the network using OpenSea's aggregated routing, which checks liquidity across decentralized exchanges to look for competitive pricing. Users can also buy and sell stablecoins on Arc, and NFT collections launching on Arc can be browsed, bought, and sold with OpenSea's marketplace features, including offers, floor prices, and collection analytics.

Because OpenSea is noncustodial, users hold supported assets in their own compatible crypto wallets, and a Circle or Arc account is not required to use OpenSea with Arc assets. As on any network, transacting on Arc requires USDC to pay fees, and users should review official documentation and understand the risks before connecting a wallet or approving a smart contract interaction.

Disclaimer: This content is for informational purposes only and should not be construed as financial or trading advice. References to specific projects, products, services, trading strategies or tokens do not constitute an endorsement, sponsorship, or recommendation by OpenSea. OpenSea does not guarantee the accuracy or completeness of the information presented, and readers should independently verify any claims made herein before acting on them. Readers are solely responsible for conducting their own due diligence before making any decisions.