# Table of contents:

• Introduction
• Authentication
  • Using Cookies
  • Using SOAP
• Actions
  • Actions that we don't know much about
• Shared Templates

# Introduction

The Contact Sharing Service (SharingService) is a SOAP (XML) Web Service. It was introduced with MSNP13.

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.

Related: Address Book Service (for Forward List (FL) members).

# Authentication

This service requires Passport Authentication, either using Passport SSI 1.4 or Passport SOAP (RST).

There are two ways to authenticate.

# Using Cookies

The easiest way to authenticate is by setting the MSPAuth cookie to the MSPAuth value from your Passport Compact Token (everything after t= and before &p=)

This can be done using a token for either contacts.msn.com or messenger.msn.com.

# Using SOAP

Clients from MSNP15 and up use SOAP to authenticate with the service. See the ABAuthHeader section for more info.

This method of authentication only works with a token for contacts.msn.com.

# 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)

# Actions that we don't know much about

• UpdateMember (internal name: Sharing.Push.Member.Edit)
• 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)

# Shared Templates

Being based on the Address Book Service, both the request (client) and response (server) use the exact same boilerplate.