${AUCTION_BID_ID}

What it expands to

ID of the bid, from BidResponse.bidid.

Expands in notice URLs and adm. It carries BidResponse.bidid, the bidder's own response identifier, so the buyer can tie a notice back to internal bid state.

What to watch for

bidid is optional on the response. If you rely on this macro for reconciliation, set bidid on every response; an empty substitution means the response never carried one.

Encoding

When a macro rides inside another URL as a query parameter, the expanded value must survive URL parsing: exchanges support suffixed forms like ${AUCTION_BID_ID:B64} (base64) where documented, and values containing reserved characters must be percent-encoded. An unencoded expansion is the most common reason a notice URL truncates at the first ampersand.

Related

• All substitution macros
• Where nurl, burl, and lurl fire in the delivery flow
• Loss reason codes
• ${AUCTION_ID}
• ${AUCTION_IMP_ID}
• ${AUCTION_SEAT_ID}
• ${AUCTION_AD_ID}
• ${AUCTION_PRICE}