Add extras to a cart | TTG Developer Portal

curl -X POST https://stg.ttix.io/api/v3/carts/6aac14d3-5826-4da8-98b6-9e68c28629d6/items \
     -H "X-TT-Platform: android" \
     -H "X-TT-API-Key: <apiKey>" \
     -H "Content-Type: application/json" \
     -d '{
  "items": [
    {
      "occurrenceId": "123",
      "inventoryItemId": "eyJwcm92aWRlcklkIjo0NTYsInNlYXRJZCI6IlNUQUxMUy1BLTEifQ",
      "priceOptionId": "eyJwcm92aWRlckNvZGUiOiJGVUxMUFJJQ0UiLCJob2xkQ29kZSI6IjE1NzM5In0",
      "quantity": 1
    }
  ]
}'

{
  "id": "6aac14d3-5826-4da8-98b6-9e68c28629d6",
  "expiresAt": "2026-03-15T19:40:00Z",
  "items": [
    {
      "id": "Qm9va2luZ3Mx",
      "event": {
        "id": "123",
        "name": "Hamilton"
      },
      "occurrence": {
        "id": "456",
        "startsAt": "2026-03-15T19:30:00-05:00"
      },
      "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",
        "extendedDescription": "Includes a complimentary drink. **Over 18s only.**"
      },
      "priceOption": {
        "category": {
          "name": "Adult",
          "id": "4471",
          "description": "Ages 3-12"
        },
        "sellPrice": {
          "amount": 18500,
          "currency": "USD"
        },
        "id": "eyJjIjoiRlVMTCJ9",
        "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_AQAAAAPoAAAABk9yY2hlc3RyYS1BLTEwMQ",
        "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",
          "extendedDescription": "Includes a complimentary drink. **Over 18s only.**"
        },
        "priceOptions": [
          {
            "category": {
              "name": "Adult",
              "id": "4471",
              "description": "Ages 3-12"
            },
            "sellPrice": {
              "amount": 18500,
              "currency": "USD"
            },
            "id": "eyJjIjoiRlVMTCJ9",
            "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,
        "selectionGroup": {
          "inventoryItemIds": [
            "v1_AQAAAAPoAAAABk9yY2hlc3RyYS1BLTEwMQ",
            "v1_AQAAAAPoAAAABk9yY2hlc3RyYS1BLTEwMg"
          ]
        },
        "selectionBlocked": {
          "chainSize": 3
        },
        "compatibleOccurrenceWindow": {
          "opensAt": "2026-03-01T10:00:00-05:00",
          "closesAt": "2026-03-01T22:00:00-05:00"
        }
      }
    ]
  },
  "voucher": {
    "code": "SUMMER20",
    "discount": {
      "amount": 18500,
      "currency": "USD"
    }
  },
  "totalTaxes": {
    "amount": 18500,
    "currency": "USD"
  }
}

Adds one or more extras (such as merchandise, drinks, or parking) to an existing cart in a single request. Pick each extra from the cart’s options.extras list and send its inventory item ID with one of its price option IDs and a quantity. The request is held as a unit: either every item is added and the repriced cart comes back, or nothing changes and one error is returned. When one item is at fault, the error’s param names it, for example items[1].priceOptionId; a refusal of the summed quantity (over a cap or the remaining availability) or by the venue’s system names no item.

Only Extra inventory items can be added to an existing cart
Each item names the occurrence it is for — the cart’s occurrence, or, for an extra with its own schedule (a guided tour, parking), the occurrence selected for it; items in one request may name different occurrences for that reason
Two items naming the same extra and price option, or an item naming an extra already on the cart, merge into one line with the quantities summed; caps apply to that summed quantity

Adds one or more extras (such as merchandise, drinks, or parking) to an existing cart in a single request. Pick each extra from the cart's `options.extras` list and send its inventory item ID with one of its price option IDs and a quantity. The request is held as a unit: either every item is added and the repriced cart comes back, or nothing changes and one error is returned. When one item is at fault, the error's `param` names it, for example `items[1].priceOptionId`; a refusal of the summed quantity (over a cap or the remaining availability) or by the venue's system names no item. - Only `Extra` inventory items can be added to an existing cart - Each item names the occurrence it is for — the cart's occurrence, or, for an extra with its own schedule (a guided tour, parking), the occurrence selected for it; items in one request may name different occurrences for that reason - Two items naming the same extra and price option, or an item naming an extra already on the cart, merge into one line with the quantities summed; caps apply to that summed quantity

Authentication

X-TT-API-Keystring

API Key authentication via header

Path parameters

cartIdstringRequiredformat: "(?i)^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$"

Request

This endpoint expects an object.

itemslist of objectsRequired

Response

Extras added to the cart.

idstring

Cart ID

expiresAtstring

UTC timestamp when the cart hold expires and inventory is released. Clients should display a countdown timer and warn users before expiration.

itemslist of objects

Items currently in the cart (held inventory). Each item’s priceOption carries the itemized fees[] disclosure. Protection and credits are NOT items — see receiptLines.

receiptLineslist of objects

Server-ordered display lines for receipt rendering. Iterate in sequence. Always includes SubtotalLine. Conditionally: VoucherLine, ProtectionLine, CreditLine. Fees are never a receipt line — they are disclosed per item on priceOption.fees.

totalobject

Monetary amount in minor units (cents for USD). Never uses floating point to avoid precision errors.

protectionobjectOptional

Protection covering all items. Null if not added.

optionsobjectOptional

Options that can be applied to this cart. Each key is present only when that option is available.

voucherobjectOptional

A promo code applied to a cart.

totalTaxesobjectOptional

Monetary amount in minor units (cents for USD). Never uses floating point to avoid precision errors.

Authentication

Path parameters

Headers

Request

Response