Glossary · Learn arc
A–Z · plain English

Glossary.

Every term we use, defined briefly. Anchor links throughout the site point here.

Arc aka Arc network, Arc L1

A Layer 1 blockchain built by Circle, optimized for stablecoin payments. EVM-compatible, ~1-second finality via Malachite BFT, uses USDC as the gas token.

See also: USDC, Malachite, gas, Circle

CCTP aka Cross-Chain Transfer Protocol

Circle's native mechanism for burning USDC on one chain and minting it on another, moving USDC between chains (Ethereum, Solana, Arc, etc.) without third-party bridge risk.

See also: USDC, Circle

Circle

The financial-tech company that issues USDC and built Arc. Also publishes the Circle Agent Stack (CLI, agent wallets, services marketplace, skills).

See also: USDC, Arc

gas aka transaction fee, network fee

The fee paid to a blockchain's validators to include your transaction. Most chains charge gas in a volatile native token (ETH, SOL). Arc charges in USDC; see the concept page on USDC-as-gas.

See also: USDC, Arc

Malachite aka Malachite BFT

The Byzantine Fault Tolerant consensus engine used by Arc. Provides deterministic ~1-second finality (vs. probabilistic finality on chains like Bitcoin or Ethereum).

See also: Arc

stablecoin

A cryptocurrency designed to hold a stable value; most are pegged 1:1 to a fiat currency like the US dollar. USDC, USDT, and USDS are the largest by market cap.

See also: USDC

USDC aka US Dollar Coin

A stablecoin issued by Circle that is fully backed 1:1 by US dollar reserves (cash and short-duration Treasuries). On Arc, USDC is both what you send and what you pay fees in.

See also: stablecoin, Arc, gas

x402 aka HTTP 402

An HTTP protocol where a server responds with status 402 Payment Required and a USDC price; the client pays, retries, and gets 200 OK. Turns any API endpoint into a paid endpoint without API keys.

See also: USDC, Arc