Assets and chains
Arc
Arc is a layer-1 blockchain from Circle. Public mainnet launched on 16 September 2026. The chain id is 5042. Arc's docs say the native gas token is USDC with 18 decimals. This index's x402 scan uses a different 6-decimal USDC contract and starts Arc history on the mainnet date.
Explanation
Circle's launch announcement dates public mainnet to 16 September 2026. The connect docs list chain id 5042, the RPC https://rpc.mainnet.arc.io, and USDC as the native gas token with 18 decimals. Gas denominated in USDC is a property of the chain. It is not, by itself, an agent payment.
The payment contract this index follows is the 6-decimal USDC ERC-20 at 0x3600000000000000000000000000000000000000. The 18-decimal system transfer is ignored so gas is not added to commerce. Circle's facilitator is an x402 facilitator on this chain. That volume stays in x402. It is not also reported as a separate nanopayments protocol, which would count the same settlements twice.
Live data
Related terms
Sources
- Circle launches Arc mainnet — Circle
- Connect to Arc — Arc
- USDC contract addresses — Circle
- Agent GDP methodology — Agent GDP