Independent A growing family of specifications lets autonomous agents establish identity, delegate authority, record what they did, and move money. None of them makes one party financially answerable to another for a result that was not delivered. This document specifies PACT, which adds liability as a required, co-signed member of an agent contract and propagates it through a subcontract tree. PACT defines the Verifiable Task Contract, a signed JSON object binding parties, scope, price, verification profile, and an explicit allocation of liability; the Delivery object that a contract is judged against; an escrowed settlement procedure whose release is conditioned on a stated assurance level rather than on elapsed time; and a subcontract tree in which a parent's Work Attestation commits to its children by Merkle root and liability cascades upward. PACT does not define an identity format, an authorization model, an audit architecture, a transparency service, a payment rail, or a reputation system. It composes existing work for all of these. Its settlement loop is an instance of optimistic fair exchange, and its bond-sizing rule is the classical deterrence bound; both are cited rather than reintroduced.