Two-stage funding

At bounty creation, maker publishes the proof-of-funds vTXO, signaling they have enough sats to fund the bounty. After taker's acceptance, the maker constructs and funds the real four-leaf escrow vTXO. The taker's client verifies the bounty's vTXO after fetching it from the Ark server.

Note: The taker's client gives a warning if the escrow verification fails. The taker should not start working before verification passes.

Bounty deadline

When funding the escrow, the maker sets a deadline for the bounty according to the negotiated terms. After the deadline passes, maker can reclaim the funds from the escrow vTXO unilaterally. This means the taker must complete the bounty within this timeframe.