Cancel a trade

POST /api/trades/:id/cancel

User · buyer only

Refunds the escrow to the seller.

Preconditions

• Trade is ESCROW_LOCKED (not yet marked paid)

Sequence

1. Claim → REFUNDING.
2. Submit the refund transaction (remove signer, merge to seller).
3. → CANCELLED with refundTxHash, cancelReason: "BUYER_CANCELLED"; write ESCROW_REFUND ledger entry and system message.
4. Reactivate the order if it hasn't expired (broadcasts order:created).

Response 200

Updated trade details with links.refund.

Errors

Status	Code	Cause
403	FORBIDDEN	Not the buyer
409	CONFLICT	Already paid, finished, or concurrent change
502	STELLAR_TX_FAILED	Rejected; status restored
503	HORIZON_UNAVAILABLE	Outcome unknown; reconciled automatically