A token representing the application-level acknowledgement code that indicates the response status (e.g., success). The AckCodeType list specifies the possible values for the Ack field.

This container is conditionally returned in the PlaceOffer call response if eBay wants to challenge the user making the call to ensure that the call is being made by a real user and not a bot. This container consist of an encrypted token, the URL of the image that should be displayed to the user, or the URL of an audio clip for sight-impaired users. After receiving this data in the response, the caller must make another PlaceOffer call, this time passing in the encrypted token and one of the URLs that was received in the previous call response.

This refers to the specific software build that eBay used when processing the request and generating the response. This includes the version number plus additional information. eBay Developer Support may request the build information when helping you resolve technical issues.

Most Trading API calls support a MessageID element in the request and a CorrelationID element in the response. If you pass in a MessageID in a request, the same value will be returned in the CorrelationID field in the response. Pairing these values can help you track and confirm that a response is returned for every request and to match specific responses to specific requests. If you do not pass a MessageID value in the request, CorrelationID is not returned.

Note: GetCategories is designed to retrieve very large sets of metadata that change once a day or less often. To improve performance, these calls return cached responses when you request all available data (with no filters). When this occurs, the MessageID and CorrelationID fields aren't applicable. However, if you specify an input filter to reduce the amount of data returned, the calls retrieve the latest data (not cached). When this occurs, MessageID and CorrelationID are applicable.

Information that explains a failure due to a duplicate InvocationID being passed in.

Unique Identifier of Recipient user ID of the notification. Only returned by Platform Notifications (not for regular API call responses).

A list of application-level errors (if any) that occurred when eBay processed the request.

An application subscribing to notifications can include an XML-compliant string, not to exceed 256 characters, which will be returned. The string can identify a particular user. Any sensitive information should be passed with due caution.

To subscribe to and receive eBay Buyer Protection notifications, this field is required, and you must pass in 'eBP notification' as a string.

Expiration date of the user's authentication token. Only returned within the 7-day period prior to a token's expiration. To ensure that user authentication tokens are secure and to help avoid a user's token being compromised, tokens have a limited life span. A token is only valid for a period of time (set by eBay). After this amount of time has passed, the token expires and must be replaced with a new token.

Supplemental information from eBay, if applicable. May elaborate on errors (such as how a listing violates eBay policies) or provide useful hints that may help a seller increase sales. This data can accompany the call's normal data result set or a result set that contains only errors.

Applications must recognize when the Message field is returned and provide a means to display the listing hints and error message explanations to the user.

The string can return HTML, including TABLE, IMG, and HREF elements. In this case, an HTML-based application should be able to include the HTML as-is in the HTML page that displays the results. A non-HTML application would need to parse the HTML and convert the table elements and image references into UI elements particular to the programming language used. As usual for string data types, the HTML markup elements are escaped with character entity references (e.g.,<table><tr>...).

Event name of the notification. Only returned by Platform Notifications.

A Base64-encoded MD5 hash that allows the recipient of a Platform Notification to verify this is a valid Platform Notification sent by eBay.

Recipient user ID of the notification. Only returned by Platform Notifications.

This value represents the date and time when eBay processed the request. The time zone of this value is GMT and the format is the ISO 8601 date and time format (YYYY-MM-DDTHH:MM:SS.SSSZ). See the Time Values section in the eBay Features Guide for information about this time format and converting to and from the GMT time zone.

Note: GetCategories and other Trading API calls are designed to retrieve very large sets of metadata that change once a day or less often. To improve performance, these calls return cached responses when you request all available data (with no filters). When this occurs, this time value reflects the time the cached response was created. Thus, this value is not necessarily when the request was processed. However, if you specify an input filter to reduce the amount of data returned, the calls retrieve the latest data (not cached). When this occurs, this time value does reflect when the request was processed.

The version of the response payload schema. Indicates the version of the schema that eBay used to process the request. See the Standard Data for All Calls section in the eBay Features Guide for information on using the response version when troubleshooting CustomCode values that appear in the response.