Circle Internet Group launched the public testnet for Arc on October 28, 2025, opening its proposed layer-one blockchain to developers and enterprises for testing. Circle said more than 100 companies and projects were participating in the network’s launch and design process.
The development moved Arc beyond the private testing anticipated when Circle introduced the project on August 12, 2025. It also gave outside developers access to an experimental network built around stablecoin payments, foreign exchange, lending and tokenized capital-market activity.
Arc was not a production mainnet on October 28. Circle explicitly described the testnet as experimental, subject to planned or unplanned downtime and intended to test performance, integrations and security before real-value activity moved to a future mainnet.
What developers could test
Circle said Arc used USDC, its dollar-denominated stablecoin, to pay transaction fees. That design was intended to make network costs predictable in dollar terms and remove the need for users to acquire a separate, volatile token solely for gas.
The testnet was EVM-compatible, allowing developers to use tooling associated with the Ethereum Virtual Machine. Circle also described deterministic sub-second finality secured by Malachite, a Byzantine fault-tolerant consensus engine. These were design and performance claims from the network’s developer, not independently audited production measurements.
Services available for testing included USDC and EURC, Circle’s Cross-Chain Transfer Protocol, Circle Gateway and wallet-development tools. Developers could deploy smart contracts, test token transfers and swaps, conduct cross-chain transfers, and evaluate wallet flows using USDC for fees.
Several other announced capabilities were not yet available. Circle placed tokenized-fund support, additional liquidity services and some smart-contract developer services in a “coming soon” category. It also said support for additional stablecoins as gas, more foreign-exchange features and configurable transaction privacy remained on the roadmap.
Institutions joined an experiment, not a production network
Circle’s participant list spanned traditional finance and the crypto industry. It included BlackRock, Goldman Sachs, HSBC, Deutsche Bank, Standard Chartered, BNY, State Street, Apollo and Intercontinental Exchange. Payment and technology participants included Visa, Mastercard, Amazon Web Services, Cloudflare, FIS and Brex.
Blockchain infrastructure and application participants included Coinbase, Kraken, Chainlink, MetaMask, Fireblocks, Aave, Maple and Morpho. Circle also identified issuers testing stablecoins tied to currencies including the Australian dollar, Brazilian real, Japanese yen, Korean won, Mexican peso, Philippine peso and Canadian dollar.
Those names established that the organizations were engaging with or exploring Arc, according to Circle. They did not establish that every participant had deployed an application, processed a transaction, committed capital or agreed to operate a validator. The announcement supplied no participant-level usage totals, audited transaction statistics or contractual commitments.
Why the launch mattered
Arc placed Circle in a different strategic position from that of a stablecoin issuer merely distributing USDC across independent blockchains. By developing its own settlement network, Circle could more closely integrate transaction fees, cross-chain infrastructure, wallets and future foreign-exchange services around its products.
That integration could simplify stablecoin-based financial applications, but it also raised an unresolved neutrality question. Circle said Arc was intended to evolve into a distributed, community-driven network with broader validator participation and transparent governance. On October 28, however, Circle was still stewarding its initial development and operation, and the promised governance structure had not been demonstrated.
The event-day record therefore supported a narrow conclusion: Arc was publicly accessible for experimentation and had attracted a large, institutionally diverse roster. It did not establish mainnet readiness, decentralization, regulatory approval, sustained demand or safe operation with real money. Circle also disclosed that Arc had not been reviewed or approved by the New York State Department of Financial Services and that planned features could be modified, delayed or cancelled.
The complete source packet and revision history are retained with the newsroom record.
Automated systems may have assisted with source organization and drafting. Coinburn is accountable for the published text and maintains a revision record.
This article provides news and analysis, not investment, legal or tax advice. Digital assets are volatile and may result in total loss.