Welcome to Plaxo
Plaxo is supporting the open API specification Portable Contacts as the primary way to provide access to Plaxo users' profile, address book, and connections data. Portable Contacts is an easy-to-implement, vendor neutral API spec for accessing "people data" from any site, and it's built on top of existing open standards like vCard, JSON, OAuth, and XRDS-Simple. Note that since the Portable Contacts spec has not yet been finalized, our implementation should be considered "early access", and it will continue to evolve with the spec. However, we are committed to providing a working implementation of the latest draft spec, along with supporting tools, to help foster and empower this community effort.
So if you'd like to start experimenting with Portable Contacts, Plaxo's API endpoint is accessible from http://www.plaxo.com/pdata/contacts and supports both OAuth and HTTP Basic authorization. Our API endpoint and OAuth endpoints are discoverable from http://www.plaxo.com/oauth/xrds, and also we provide an X-XRDS-Location reference there from our homepage. We also have a general-purpose Portable Contacts test harness available at http://www.plaxo.com/pdata/testClient. It's pre-configured to work with Plaxo's API, but it can be used with any compliant Portable Contacts provider. Use of Plaxo's API is covered by our Terms of Service.
Note also that the latest version of the OpenSocial RESTful APIs are now wire-compatible with Portable Contacts for the overlapping portion (read-only access to people data, as of version 0.8.1). The reference implementation in Shindig (available in Java and PHP) thus supports Portable Contacts, and may be a useful starting place if you'd like to be a Provider too.
So dive in, join the community, and if you have any questions—or if you build something cool with Portable Contacts—please feel free to contact me (Joseph Smarr) and let me know!
