Changelog [ENG]

This article contains a list of changes made to the documentation, with links to the individual articles. The list of changes is organized by modification date.

Change category:

MAJOR – used to identify backward-incompatible or breakthrough changes relative to the currently published documentation and the current version of the API.
MINOR – used to identify successive increments of functionality in the documentation and API that do not result in incompatibilities.
PATCH – used to identify changes/revisions that do not cause backward incompatibility or increments of functionality and informational substitutions.

26.05.2026

MINOR - Change in payment method format for the `payment_type` field

What changed?

The payment_type field previously accepted an array of values (e.g. CARD, BLIK_CODE, etc.). The new recommended format is an empty list: "payment_type": [].
The old format remains backward-compatible - support will be removed in a future version.

API methods:

18.11.2025

PATCH - Removed Articles on Promoted Products

Articles related to the Promoted Products (hot products) functionality have been removed from the documentation. This change is due to the discontinuation of this functionality in the InPost Pay service.

01.09.2025

MINOR - Free basket

Functionality using the object available in future versions of the application.

The merchant, when creating or updating a basket in the InPost Pay application, will be able to define whether the basket is free.

Free basket flow:

The merchant sends the basket to InPost with a new flag free_basket = true, which indicates whether the basket without delivery costs is free.
InPost validates whether the basket value equals 0
- If the basket value without delivery costs equals 0, the flag is recorded in the basket details. Proceed to the next step.
- If the basket value excluding delivery costs does not equal 0, the flag is ignored (indicating the basket is not free). End of process.
The application retrieves the basket with the flag free_basket = true and presents it to the user.
The customer defines the delivery method/additional delivery options that may affect the price.
- If the total gross amount (basket + delivery) = 0, the application does not present the payment selector.
- If the total gross amount (basket + delivery) > 0, the application presents the payment selector.
The customer clicks "Buy and Pay" (case where basket + delivery = 0).
InPost sends a POST /v1/izi/order request to the merchant where, for the basket with a value of basket + delivery = 0, the following information is provided:
- basket_price.gross=0
- payment_type with the new value FREE_ORDER indicating that it is a free order.
The merchant creates the order and in the response POST /v1/izi/order sends back the order details with payment_type=FREE_ORDER.
The order is recorded in InPost as paid and is presented to the customer in the application.
End of process.

Scope of API changes:

Adding free_basket to:

endpoints exposed by the merchant:
- response GET /v1/izi/basket/{basket_id} summary.free_basket
- response POST /v1/izi/basket/{basket_id}/confirmation summary.free_basket
- response POST /v1/izi/basket/{basket_id}/event summary.free_basket
endpoints exposed by InPost:
- request PUT /v2/izi/basket/{basket_id} summary.free_basket

Handling of the new payment_type=FREE_ORDER indicating that the order is free on endpoints:

endpoints exposed by the merchant:
- request POST /v1/izi/order - the application will pass payment_type=FREE_ORDER only if the basket value with delivery costs equals 0 and only for the basket where the flag free_basket = true was defined.
- response POST /v1/izi/order - the merchant should return the value payment_type=FREE_ORDER for the created free order.
- response GET /v1/izi/order/{order_id} - the merchant should return the value payment_type=FREE_ORDER for the free order.
endpoints exposed by InPost:
- response GET /v1/izi/orders - if there are free orders in the list of orders, InPost will return them with payment_type=FREE_ORDER.

10.07.2025

MINOR - Hot products - affiliate link `product_link`

Handling promoted products using an affiliate link.

04.07.2025

PATCH - Added basket_additional_parameters object

Merchant, when creating or updating a basket, has the ability to pass additional parameters along with the basket details. These parameters can be used, for example, to associate or identify the basket with a campaign, or to add other parameters that will facilitate basket management by the Merchant. Additional parameters are not displayed in the application.

Added object:

 "basket_additional_parameters": [
      {
        "key": "string",
        "value": "string"
      }
    ]

in API: