# Introduction
The Contact Sharing Service (SharingService) is a SOAP (XML) Web Service.
Introduced with [MSNP13](../versions/msnp13.md).

It manages the Messenger Service's Allow List (AL), Block List (BL), Reverse List (RL), and Pending List (PL) members.

It's default HTTP URL is `http://byrdr.omega.contacts.msn.com/abservice/SharingService.asmx`.
It's default HTTPS URL is `https://byrdr.omega.contacts.msn.com/abservice/SharingService.asmx`.

This service requires Passport authentication.

Related: [Address Book Service](abservice.md) (for Forward List (PL) members).

# Actions
*All actions listed have the prefix of
`http://www.msn.com/webservices/AddressBook/`.*

* FindMembership (internal name: `Sharing.Pull.Membership`)
* AddMember (internal name: `Sharing.Push.Member.Add`)
* DeleteMember (internal name: `Sharing.Push.Member.Delete`)
* UpdateMember (internal name: `Sharing.Push.Member.Edit`)

## Actions that we don't know much about
* AddService (internal name: `Sharing.Push.Service.Add`)
* UpdateService (internal name: `Sharing.Push.Service.Edit`)
* FindInverseService (internal name: `Sharing.Pull.InverseServices`)
* DeleteInverseService (internal name: `Sharing.Push.Document.Delete`)
* AcceptInvitation (internal name: `Sharing.Push.Invitation.Accept`)
* DeclineInvitation (internal name: `Sharing.Push.Invitation.Decline`)
* AddNamespace (internal name: `Sharing.Push.Namespace.Add`)
* DeleteNamespace (internal name: `Sharing.Push.Namespace.Delete`)