Access the Address Book XML/JSON API using the following URL:

The URL parameters are as follows:

GET HTTP is the recommended method for calling searchContacts and getCategories.

POST is required for the write requests addContacts and synchronize. The format of the POST body should match the output format specified by the format parameter. That is, it should be either a valid XML document or a valid JSON structure, respectively. See Data Representation Formats below.

Developers can use the following URL request to resolve an email address to the full name of a contact, including the YDN-specific authentication parameters WSSID and appid:

The above query retrieves the name of a contact with the specified email address. The actual email address that matched is not returned in the Response, because the query only requests that name fields be returned.

Sample Response:

The Address Book XML/JSON API uses HTTP for transport. Communication parameters are negotiated as part of the HTTP request header mechanism, and the XML/JSON API does not influence this negotiation in any way. In particular, the server may choose to use the chunked Transfer-Encoding, and in this case the Response headers may not include a Content-Length header. Calls to the Address Book XML/JSON API should not depend on the Content-Length header being present in the Response. Also, if the HTTP headers sent by the client imply that the gzip content-encoding can be used, the server response may use this encoding. Users of libraries like curl should not need to worry about details of the HTTP protocol. A common mistake, however, is to assume that a Content-Length header will be present in the Response, which is not guaranteed.

POST requests to the Address Book XML/JSON API require a Content-Type HTTP request header that matches the format specified using the format URL parameter. The following table shows this mapping.