Ask someone
Attach KAS to a message. They reply, they get it. They don't, it comes back to you.
Enforced on-chain: only the recipient can claim, and only with a reply bound to this Ask. The reply is the claim — a reply before the deadline pays them; after the deadline the escrow refunds to you (anyone can trigger it, and the chain forces it to pay only your address, your locked amount minus a small network fee). No protocol fees, ever. Your message and their reply are encrypted; addresses, amount and deadline are public on-chain.
The honest caveat (for whoever replies):a reply that arrives around the deadline races that refund, and if the refund lands first the reply is rejected. You'd lose only the network fee on that failed claim — never your escrow. The locked funds can never be taken by a third party or redirected; they only ever pay the recipient on time, or refund the asker after the deadline. So reply to Asks you have some reason to trust, and read a failed late claim as the asker declining, not a lost deposit.