Exfer: A Peer-to-Peer Settlement Protocol for Autonomous Machines Exfer is a permissionless proof-of-work blockchain for autonomous machine-to-machine commerce. It combines Argon2id memory-hard mining, an extended UTXO model, and Exfer Script — a total functional combinator language — for transaction conditions. The protocol is the minimum infrastructure that turns independent agents into an economy. All scripts terminate. Costs are statically computable before execution. The UTXO model eliminates global state and reentrancy. An autonomous agent can construct a transaction, compute its exact…