Cairo and StarkNet Contract Development

Cairo's Position in the Language Landscape

Cairo is StarkNet's smart-contract language, designed by Starkware specifically to translate efficiently into STARK proofs. Cairo 1.0 (released 2023, with continued evolution into Cairo 2.x) is a Rust-inspired language that produces compact, prover-friendly bytecode. The trade-off vs Solidity: Cairo isn't EVM-compatible, so Solidity contracts can't be ported directly; they must be rewritten. The benefit: dramatically faster proving than EVM-based ZK systems.

What Makes Cairo Different

Cairo borrows much from Rust: explicit memory management, traits, pattern matching, immutability by default. But it's specialised for the STARK proving system. Some operations that are cheap in Solidity (modular arithmetic) translate easily; others (bitwise operations, byte manipulation) are more expensive in Cairo because they translate poorly to polynomial constraints. Production Cairo development requires thinking about both correctness and proving cost — a different mental model than Solidity gas optimisation.

Account Abstraction Native

Every account on StarkNet is a smart contract. There are no EOAs. This means signature verification, gas payment, and replay protection are all handled by your account contract — not the protocol. Different wallets (Argent, Braavos) provide different account implementations with different features (multi-sig, social recovery, session keys, passkeys). Cairo's account-abstraction-native design is structurally cleaner than Ethereum's ERC-4337 retrofit.

• Cairo 1.0+ is Rust-inspired, designed for STARK proving efficiency
• Not EVM-compatible; Solidity contracts must be rewritten
• Account abstraction is the only option — no EOAs
• Production wallets (Argent, Braavos) leverage AA-native design for UX features