Stellar's Soroban smart contract runtime features a composable authorization model that decouples authorization from fee payment, enabling sponsored transactions, multi-party swaps, and programmable accounts through detachable auth entries and flexible verification logic.
Stellar's authorization framework in Soroban separates what needs authorization (declared by contracts via require_auth), how it's verified (handled by the runtime), and the authorization data itself (detachable from transactions). This design enables sponsored transactions where a relayer pays fees while a user authorizes specific operations, atomic multi-party swaps where participants sign independent auth entries, and programmable contract accounts with custom verification logic like multi-sig or spending limits. Auth trees capture only the functions that call require_auth for an address, providing signers visibility into exactly what they're authorizing. Automatic invoker auth allows direct contract-to-contract calls to succeed without additional signatures, enabling frictionless composition across protocols.
