What is Arc?
Arc is an EVM-compatible layer 1 from Circle. It pairs the Reth execution client with Malachite BFT consensus, and it uses USDC for gas instead of a volatile native token.Arc is testnet only. Circle has not launched a mainnet yet, so every endpoint and example on these pages targets Arc Testnet.
Key characteristics
- USDC as gas — transaction fees are paid in USDC, so costs are predictable in dollar terms.
- Sub-second blocks — Arc produces a block roughly every 0.5 seconds under Malachite BFT consensus, with deterministic finality rather than probabilistic confirmation.
- Standard EVM surface — the
eth_*methods behave as they do on any Reth node, so existing tooling works unchanged. - Full debug and trace — both the
debug_*namespace and the Parity-styletrace_*namespace are available. - A custom
arc_*namespace — two methods that have no equivalent on other chains, covering the node build and the consensus commit certificate.
Network details
Namespaces
Chainstack Arc nodes exposeeth, debug, trace, txpool, net, web3, and rpc, plus the custom arc namespace.
Two things that differ from other EVM chains
Pending transactions are not observable. Arc rejects botheth_newPendingTransactionFilter and eth_subscribe("newPendingTransactions") with -32001. The txpool_* methods do work, so you can inspect the pool, but you cannot stream new pending transactions as they arrive.
Most historical queries bill as archive. The standard rule is that a request 127 or more blocks behind the tip bills as archive. At roughly 0.5 seconds per block that covers only about a minute of history, against roughly 25 minutes on Ethereum. See Request units.
Getting an endpoint
- Sign up with Chainstack.
- Deploy a node on Arc Testnet.
- View node access and credentials.