Disputes and the arbiter - Simpuru

When a delivery is disputed, the arbiter decides who gets the money. It does not read the prompt or judge its quality. It checks three facts, each against something fixed before or at the lock:

Check	Compared with	Proves
The escrow is for this listing	`input_hash` in the escrow vs the commitment to `{ listingId, contentHash }`	This escrow paid for this listing
The output is what the seller posted	`sha256(lockTxHash + ";" + output)` vs `result_hash` in the escrow	The seller put its name to this output on chain
The output is what was listed	`sha256(output)` vs the listing’s `contentHash`	What was delivered is what was sold

The seller wins only if all three hold. Otherwise the buyer is paid back.

Who brings the evidence

The output is shown by whoever calls the arbiter. An output that does not match the seller’s on-chain result proves nothing on its own: it could be the buyer hiding the real delivery. So such a call gets no verdict until an evidence deadline. If by then nobody has shown the output the seller posted, the seller loses for not proving delivery.

The payout

The arbiter builds the dispute payout and signs it with Simpuru’s arbiter key (a CIP-8 signature the validator checks). The validator only accepts it after the dispute unlock time (see Deadlines), so an early or forged payout is rejected on chain.

On preprod

Buyer wins (wrong file): lock d7485072…, seller posts the hash of the wrong file ff8b418a…, dispute c1e28c30…, arbiter pays the buyer 7132086b…
In production, settled by the hosted arbiter: lock 7863336b…, arbiter pays the buyer back 52c7d537…
Seller wins (right delivery): arbiter pays the seller 763b27fe…