Add an extra 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 '{
  "occurrence_id": "123",
  "inventory_item_id": "eyJwcm92aWRlcklkIjo0NTYsInNlYXRJZCI6IlNUQUxMUy1BLTEifQ",
  "price_option_id": "eyJwcm92aWRlckNvZGUiOiJGVUxMUFJJQ0UiLCJob2xkQ29kZSI6IjE1NzM5In0",
  "quantity": 1
}'

{
  "id": "6aac14d3-5826-4da8-98b6-9e68c28629d6",
  "expires_at": "2026-03-15T19:40:00Z",
  "items": [
    {
      "id": "001",
      "event": {
        "id": "123",
        "name": "Hamilton"
      },
      "occurrence": {
        "id": "456",
        "starts_at": "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",
          "postal_code": "10036",
          "country": "US",
          "latitude": 40.759,
          "longitude": -73.9845
        },
        "timezone": "America/New_York"
      },
      "inventory_variant": {
        "_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"
      },
      "price_option": {
        "category": {
          "name": "Adult"
        },
        "sell_price": {
          "amount": 18500,
          "currency": "USD"
        },
        "id": "eyJjIjoiRlVMTCJ9",
        "list_price": {
          "amount": 18500,
          "currency": "USD"
        },
        "max_quantity_per_order": 4,
        "promotion": {
          "id": "promo-opening-week",
          "name": "Opening Week Special",
          "description": "40% off Orchestra seats for opening week performances."
        }
      },
      "quantity": 1,
      "delivery": {
        "method": {
          "name": "E-ticket"
        },
        "instructions": "Your e-tickets will be emailed to you before the performance."
      }
    }
  ],
  "receipt_lines": [
    {
      "label": "Subtotal",
      "total": {
        "amount": 18500,
        "currency": "USD"
      },
      "sign": "positive",
      "_type": "SubtotalLine"
    }
  ],
  "total": {
    "amount": 18500,
    "currency": "USD"
  },
  "protection": {
    "id": "prot_001",
    "price_per_item": {
      "amount": 18500,
      "currency": "USD"
    },
    "total": {
      "amount": 18500,
      "currency": "USD"
    },
    "status": "ELIGIBLE"
  },
  "options": {
    "currencies": [
      "USD",
      "GBP",
      "EUR"
    ],
    "payment_methods": [
      {
        "method": "CARD",
        "gateway": "ADYEN",
        "merchant_account": "EncoreTicketsOwnBrand"
      }
    ],
    "extras": [
      {
        "id": "v1_AQAAAAPoAAAABk9yY2hlc3RyYS1BLTEwMQ",
        "inventory_variant": {
          "_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"
        },
        "price_options": [
          {
            "category": {
              "name": "Adult"
            },
            "sell_price": {
              "amount": 18500,
              "currency": "USD"
            },
            "id": "eyJjIjoiRlVMTCJ9",
            "list_price": {
              "amount": 18500,
              "currency": "USD"
            },
            "max_quantity_per_order": 4,
            "promotion": {
              "id": "promo-opening-week",
              "name": "Opening Week Special",
              "description": "40% off Orchestra seats for opening week performances."
            }
          }
        ],
        "quantity_available": 1,
        "max_quantity_per_order": 6
      }
    ]
  },
  "voucher": {
    "code": "SUMMER20",
    "discount": {
      "amount": 18500,
      "currency": "USD"
    }
  },
  "total_taxes": {
    "amount": 18500,
    "currency": "USD"
  }
}

Adds an extra (such as merchandise, drinks, or parking) to an existing cart. Pick the extra from the cart’s options.extras list and send its inventory item ID with one of its price option IDs. A cart can carry several extras: send quantity above 1 for more of the same extra, and call again with other extras or price options to mix them.

Only Extra inventory items can be added to an existing cart
The item must reference the same occurrence as the cart
Adding the same extra and price option again increases its quantity

Adds an extra (such as merchandise, drinks, or parking) to an existing cart. Pick the extra from the cart's `options.extras` list and send its inventory item ID with one of its price option IDs. A cart can carry several extras: send `quantity` above 1 for more of the same extra, and call again with other extras or price options to mix them. - Only `Extra` inventory items can be added to an existing cart - The item must reference the same occurrence as the cart - Adding the same extra and price option again increases its 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.

occurrence_idstringRequired>=1 character

ID of the occurrence

inventory_item_idstringRequired>=1 character

Opaque inventory item ID from the GET inventory-items response

price_option_idstringRequired>=1 character

Opaque price option ID from the inventory item priceOptions array

quantityintegerRequired>=1

Number of units to reserve. Must be greater than or equal to 1.

Response

Extra(s) added to the cart.

idstring

Cart ID

expires_atstring

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). Does NOT include fees, protection, or credits — see receiptLines for those.

receipt_lineslist of objects

Server-ordered display lines for receipt rendering. Iterate in sequence. Always includes SubtotalLine. Conditionally: VoucherLine, ProtectionLine.

totalobject

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

protectionobject

Protection covering all items. Null if not added.

optionsobject

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

voucherobject

A promo code applied to a cart.

total_taxesobject

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

Authentication

Path parameters

Headers

Request

Response