Change an item's quantity

PATCH

/api/v3/carts/:cartId/items/:itemId

PATCH

/api/v3/carts/:cartId/items/:itemId

curl -X PATCH https://stg.ttix.io/api/v3/carts/6aac14d3-5826-4da8-98b6-9e68c28629d6/items/itemId \
     -H "X-TT-Platform: android" \
     -H "X-TT-Retailer: YOUR_RETAILER_ID" \
     -H "X-TT-API-Key: <apiKey>" \
     -H "Content-Type: application/json" \
     -d '{
  "quantity": 2
}'

{
  "data": {
    "id": "6aac14d3-5826-4da8-98b6-9e68c28629d6",
    "expiresAt": "2026-03-15T19:40:00Z",
    "expiresInSeconds": 300,
    "items": [
      {
        "id": "Qm9va2luZ3Mx",
        "event": {
          "id": "123",
          "name": "Hamilton"
        },
        "occurrence": {
          "id": "456",
          "startsAt": "2026-03-15T19:30:00-04:00",
          "doorsOpen": {
            "at": "2026-03-15T19:00:00-04:00",
            "description": "Doors open 30 minutes before the performance."
          },
          "notices": [
            {
              "name": "Audio-described performance",
              "description": "Live audio description for visually impaired patrons."
            }
          ]
        },
        "venue": {
          "id": "UmljaGFyZCBSb2RnZXJzIFRoZWF0cmU",
          "name": "Richard Rodgers Theatre",
          "address": {
            "line1": "226 W 46th St",
            "line2": "Suite 200",
            "city": "New York",
            "state": "NY",
            "postalCode": "10036",
            "country": "US",
            "latitude": 40.759,
            "longitude": -73.9845
          },
          "timezone": "America/New_York"
        },
        "inventoryVariant": {
          "_type": "AssignedSeat",
          "attributes": [
            {
              "name": "Limited Legroom",
              "category": "NEGATIVE",
              "description": "Seats in this row have reduced legroom due to a safety barrier."
            }
          ],
          "id": "ORCHESTRA-A-101",
          "name": "Orchestra A 101",
          "row": "A",
          "seat": "101",
          "section": "Orchestra",
          "description": "Closest to the stage",
          "entrance": "Door 4",
          "extendedDescription": "Includes a complimentary drink. **Over 18s only.**",
          "images": [
            {
              "url": "https://example.com/seat-views/orchestra-a-101-center.jpg"
            }
          ]
        },
        "priceOption": {
          "category": {
            "name": "Adult",
            "id": "4471",
            "description": "Ages 3-12"
          },
          "sellPrice": {
            "amount": 18500,
            "currency": "USD"
          },
          "id": "eyJwcm92aWRlckNvZGUiOiJGVUxMUFJJQ0UiLCJob2xkQ29kZSI6IjE1NzM5In0",
          "constraints": {
            "requiresCategory": [
              "string"
            ]
          },
          "listPrice": {
            "amount": 18500,
            "currency": "USD"
          },
          "discountPercentage": 30,
          "discountAmount": {
            "amount": 18500,
            "currency": "USD"
          },
          "fees": [
            {
              "type": "SERVICE_FEE",
              "value": {
                "amount": 18500,
                "currency": "USD"
              }
            }
          ],
          "maxQuantityPerOrder": 4,
          "promotion": {
            "id": "promo-opening-week",
            "name": "Opening Week Special",
            "description": "40% off Orchestra seats for opening week performances."
          },
          "isDefault": true
        },
        "quantity": 1,
        "delivery": {
          "method": {
            "name": "E-ticket"
          },
          "instructions": "Your e-tickets will be emailed to you before the performance."
        }
      }
    ],
    "receiptLines": [
      {
        "label": "Subtotal",
        "total": {
          "amount": 18500,
          "currency": "USD"
        },
        "sign": "positive",
        "_type": "SubtotalLine"
      }
    ],
    "total": {
      "amount": 18500,
      "currency": "USD"
    },
    "protection": {
      "id": "prot_001",
      "pricePerItem": {
        "amount": 18500,
        "currency": "USD"
      },
      "total": {
        "amount": 18500,
        "currency": "USD"
      },
      "status": "ELIGIBLE"
    },
    "options": {
      "currencies": [
        "USD",
        "GBP",
        "EUR"
      ],
      "paymentMethods": [
        {
          "method": "CARD",
          "gateway": "ADYEN",
          "merchantAccount": "EncoreTicketsOwnBrand"
        }
      ],
      "extras": [
        {
          "id": "v1_eyJwcm92aWRlcklkIjoxMDAwLCJzZWF0SWQiOiJPUkNIRVNUUkEtQS0xMDEifQ",
          "inventoryVariant": {
            "_type": "AssignedSeat",
            "attributes": [
              {
                "name": "Limited Legroom",
                "category": "NEGATIVE",
                "description": "Seats in this row have reduced legroom due to a safety barrier."
              }
            ],
            "id": "ORCHESTRA-A-101",
            "name": "Orchestra A 101",
            "row": "A",
            "seat": "101",
            "section": "Orchestra",
            "description": "Closest to the stage",
            "entrance": "Door 4",
            "extendedDescription": "Includes a complimentary drink. **Over 18s only.**",
            "images": [
              {
                "url": "https://example.com/seat-views/orchestra-a-101-center.jpg"
              }
            ]
          },
          "priceOptions": [
            {
              "category": {
                "name": "Adult",
                "id": "4471",
                "description": "Ages 3-12"
              },
              "sellPrice": {
                "amount": 18500,
                "currency": "USD"
              },
              "id": "eyJwcm92aWRlckNvZGUiOiJGVUxMUFJJQ0UiLCJob2xkQ29kZSI6IjE1NzM5In0",
              "constraints": {
                "requiresCategory": [
                  "string"
                ]
              },
              "listPrice": {
                "amount": 18500,
                "currency": "USD"
              },
              "discountPercentage": 30,
              "discountAmount": {
                "amount": 18500,
                "currency": "USD"
              },
              "fees": [
                {
                  "type": "SERVICE_FEE",
                  "value": {
                    "amount": 18500,
                    "currency": "USD"
                  }
                }
              ],
              "maxQuantityPerOrder": 4,
              "promotion": {
                "id": "promo-opening-week",
                "name": "Opening Week Special",
                "description": "40% off Orchestra seats for opening week performances."
              },
              "isDefault": true
            }
          ],
          "quantityAvailable": 1,
          "maxQuantityPerOrder": 6,
          "minQuantityPerOrder": 4,
          "selectionGroup": {
            "inventoryItemIds": [
              "v1_eyJwcm92aWRlcklkIjoxMDAwLCJzZWF0SWQiOiJPUkNIRVNUUkEtQS0xMDEifQ",
              "v1_eyJwcm92aWRlcklkIjoxMDAwLCJzZWF0SWQiOiJPUkNIRVNUUkEtQS0xMDIifQ"
            ]
          },
          "selectionBlocked": {
            "chainSize": 3
          },
          "requirements": {
            "occurrence": {
              "earliestStart": "2026-03-01T15:00:00Z",
              "latestStart": "2026-03-02T03:00:00Z"
            }
          }
        }
      ]
    },
    "voucher": {
      "code": "SUMMER20",
      "discount": {
        "amount": 18500,
        "currency": "USD"
      }
    },
    "totalTaxes": {
      "amount": 18500,
      "currency": "USD"
    }
  }
}

Holds a different number of units of an extra already on the cart, up or down from the number held now, and returns the cart repriced. The rest of the cart is untouched — the customer keeps the same hold and the same expiry.

itemId is the id of the line on the cart response, not an inventory item ID. Two items of the same extra at different price options are separate lines with ids of their own
quantity is the number to end up holding and is at least 1. To drop the item, send DELETE /carts/{cartId}/items/{itemId}
Only an Extra item can be changed. A cart’s seats and GA are set when it is created; to release them, delete the cart with DELETE /carts/{cartId}

Authentication

X-TT-API-Keystring

API Key authentication via header

Path parameters

cartIdstringRequiredformat: "^[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{12}$"

Cart ID (UUID)

itemIdstringRequired1-64 characters

Cart item ID, as it came back on the cart response items[].id

Request

This endpoint expects an object.

quantityintegerRequired>=1

Number of units of this item to hold, up or down from the number held now. At least 1: to drop the item, send DELETE /carts/{cartId}/items/{itemId} instead.

Response headers

X-RateLimit-Limitinteger

How many requests this API key may make for this retailer in the current window. Sent only when the request was counted against that limit. A response served from cache was not counted and repeats the value it was cached with.

X-RateLimit-Remaininginteger

How many requests this API key has left for this retailer in the current window. Sent only when the request was counted against that limit. A response served from cache was not counted and repeats the value it was cached with.

Response

Cart repriced for the new quantity.

dataobject

Shopping cart containing held inventory cart items.

Errors

400

Bad Request Error

401

Unauthorized Error

403

Forbidden Error

404

Not Found Error

409

Conflict Error

410

Gone Error

429

Too Many Requests Error