Buy KBAR
One transaction, two signatures: you sign in your wallet, the seller's Keaton signer checks the deal and countersigns. Either both legs move or neither does. Testnet.
…reading the offer…
…
The deal behind this button
The offer is a published document whose id is the sha256 of its contents, so it cannot change under you. This page checked that hash before showing it. The seller's signer re-runs the same document against the exact bytes you sign, and refuses anything that does not match.
Need testnet HBAR? Hedera faucet. Watching the pool: Keaton dashboard.