Citrea is the first ZK rollup that settles directly on Bitcoin, verifies zero-knowledge proofs on-chain through BitVM, and preserves Bitcoin-level security while enabling fully programmable smart contracts through its in-house Type 2 zkEVM. The platform fosters a composable ecosystem of Bitcoin applications (₿apps) and features a compliant stablecoin, ctUSD, issued by MoonPay, alongside the first trust-minimized BTC bridge, Clementine.