Returns the blockchain actions a seller needs to accept an offer, for offers that cannot be accepted with Seaport calldata. A Solana offer is always accepted this way, because it settles through an onchain program rather than a signed order. The offer is addressed by the same identifier the get-order endpoint uses, and a criteria offer additionally requires a consideration naming the token being sold.

On Solana two fields on the returned action are load-bearing. When partially_signed_transaction is present the transaction is already cosigned: append your signature to those exact bytes and broadcast them, and do not rebuild the message from instructions, which invalidates the cosigner signature. When sponsored_fee_payer is present an OpenSea relayer pays the fee and your wallet is only a co-signer; when it is absent you pay your own fee.

Accepting fewer units than an offer's remaining quantity leaves the offer live, so a successful fill does not imply the offer is consumed.