Update a max bid

Update the current high bidder's maximum (proxy) bid on an active auction item.

The customer must currently be the high bidder. The maxAmount cannot be lower than the customer's current showing bid.

If the auction item has a reserve price that has not yet been met and the new maxAmount meets or exceeds it, the system will automatically place a bid at the reserve price.

post

Authorizations

AuthorizationstringRequired

You can retrieve your token by visiting Settings > API and clicking Generate Public Token.

Path parameters

idstringRequired

The auction item UID.

Example: 1c6af60by54hzdmgxy5ab4ypw0

Query parameters

fields[auction-items]stringOptional

Available values are startPrice, reservePrice, bidIncrementStrategy, automaticBidding, softClose, totalBids, highBidAmount, minimumBid, currentIncrement, startsAt, endsAt, position, status, reserveMet, canceledAt, archivedAt, processed, createdAt, updatedAt. You can include multiple values by separating them with a comma.

fields[variants]stringOptional

Available values are externalId, displayName, title, price, photoUrl, sku. You can include multiple values by separating them with a comma.

fields[products]stringOptional

Available values are externalId, title, vendor, type, photoUrl, handle. You can include multiple values by separating them with a comma.

fields[bids]stringOptional

Available values are amount, submittedAt, placedAt, automatic. You can include multiple values by separating them with a comma.

fields[customers]stringOptional

Available values are name, firstName, lastName, externalId, email, registeredAt, approvedAt, bannedAt, createdAt. You can include multiple values by separating them with a comma.

fields[max-bids]stringOptional

Available values are amount, createdAt. You can include multiple values by separating them with a comma.

includestringOptional

Comma-separated list of related resources to include in the response. Available values: variant, product, highBid, highBid.customer, maxBid.

Body

customerIdstringRequired

The customer UID.

maxAmountnumberRequired

The new maximum bid in major currency units (e.g. 10.50).

Responses

200

AuctionItemResource

application/vnd.api+json

401

Unauthenticated

application/vnd.api+json

403

The provided user does not have access to this resource.

application/vnd.api+json

422

The max bid could not be updated. Inspect errors[0].code for the specific reason:

• user_not_found — customer was not found for the given customerId.
• max_bid_edit_permission_denied — the customer is not the current high bidder on the auction item.
• auction_ended — the auction has already ended.
• max_amount_below_current_bid — the new maxAmount is lower than the customer's existing showing bid. meta.minimum_bid shows the existing bid amount.

application/vnd.api+json

post/auction-items/{id}/update-max-bid

POST /v1/auction-items/{id}/update-max-bid HTTP/1.1
Host: api.auctionplusapp.com
Authorization: Bearer YOUR_SECRET_TOKEN
Content-Type: application/json
Accept: */*
Content-Length: 35

{
  "customerId": "text",
  "maxAmount": 1
}

{
  "data": {
    "id": "wwvmb10q0d5n78d0t0fjy4tyhw",
    "type": "auction-items",
    "attributes": {
      "startPrice": {
        "value": 100,
        "major": "1.00",
        "display": "$1.00",
        "currency": "USD"
      },
      "reservePrice": {
        "value": 1000,
        "major": "10.00",
        "display": "$10.00",
        "currency": "USD"
      },
      "bidIncrementStrategy": {
        "strategy": "fixed_amount",
        "value": {
          "amount": {
            "value": 500,
            "major": "5.00",
            "display": "$5.00",
            "currency": "USD"
          }
        }
      },
      "automaticBidding": {
        "enabled": true
      },
      "softClose": {
        "enabled": false,
        "extendFrom": null,
        "extendDuration": null
      },
      "totalBids": 1,
      "highBidAmount": {
        "value": 5000,
        "major": "50.00",
        "display": "$50.00",
        "currency": "USD"
      },
      "minimumBid": {
        "value": 5500,
        "major": "55.00",
        "display": "$55.00",
        "currency": "USD"
      },
      "currentIncrement": {
        "value": 500,
        "major": "5.00",
        "display": "$5.00",
        "currency": "USD"
      },
      "startsAt": "2026-09-24T19:51:40.000000Z",
      "endsAt": "2026-09-24T20:51:40.000000Z",
      "position": null,
      "status": "active",
      "reserveMet": true,
      "canceledAt": null,
      "archivedAt": null,
      "processed": false,
      "createdAt": "2026-09-24T19:51:40.000000Z",
      "updatedAt": "2026-09-24T19:51:40.000000Z"
    },
    "relationships": {
      "variant": {
        "data": {
          "type": "variants",
          "id": "text"
        }
      },
      "product": {
        "data": {
          "type": "products",
          "id": "text"
        }
      },
      "highBid": {
        "data": {
          "type": "bids",
          "id": "text"
        }
      },
      "maxBid": {
        "data": {
          "type": "max-bids",
          "id": "text"
        }
      }
    }
  }
}