# Table of contents:

Introduction
Command information
Known changes
Client-server communication example

# Introduction

MSNP3 is the second released version of the Messenger Service Notification Protocol.
It was introduced officially in Client Version 2.0.0083.

# Command information

It introduces the notification service commands:

No switchboard or dispatch commands were known to be introduced in this version.

No commands were known to be removed in this version.

# Known changes

(from MSNP2):

XFR: Added a new parameter that is always 0. No use is known or documented.
Added Passport Site IDs to URL (parameter 3).
Content types of both e-mail notifications have changed.
- The initial configuration content type was changed from application/x-msmsgsemailnotification to text/x-msmsgsinitialemailnotification.
  The content remains the same.
- The notification content type was changed from application/x-msmsgsemailnotification to text/x-msmsgsemailnotification.
  The only difference in content is the added id header.
Added Hotmail's Passport Site ID to new e-mail notifications.
SND: Added a target language parameter and a client library parameter, similar to the one in CVR.
Initial profile: Added Passport integration fields.
Font information has been added to Switchboard MSG commands.
Non-protocol: Client can now use non-Hotmail domains in relevant places.
Non-protocol: WebTV 2.5+ clients (example@webtv.net) can talk to other users (example@hotmail.com)
Clear-Text Password (CTP) authentication scheme removed. Use the MD5 scheme instead. Applies to both INF and USR.
Official Client: Automatic login form now supports Passport authentication if parameter 3 is set in URL.
To generate creds, MD5 hash the following as one concatenated string:
- auth (from Initial Profile's MSPAuth, also included in the form) +
- sl (amount of seconds since LoginTime, also included in the form) +
- passwd (plain-text password).
Official Client: Legacy automatic login form parameters has changed. This only applies for URL commands without parameter 3.
To generate k2, MD5 hash the following as one concatenated string:
- login (The local-part of your user handle, also included in the form) +
- k1 (A short 2 digit number that you generate and is also included in the form) +
- passwd (plain-text password).
Official Client: Removed URL service PASSWORD.
Official Client: Disabled inviting people to the service (needs confirmation).

# Client-server communication example

NOTE: This has been line-broken. Lines beginning with .. followed by a space are continuations of the previous line.

C: VER 1 MSNP3 MSNP2 CVR0
S: VER 1 MSNP3
C: INF 2
S: INF 2 MD5
C: USR 3 MD5 I example@hotmail.com
S: XFR 3 NS 10.0.0.5:1863 0

Client disconnects from server.

Client opens a connection to 10.0.0.5:1863.

C: VER 4 MSNP3 MSNP2 CVR0
S: VER 4 MSNP3
C: INF 5
S: INF 5 MD5
C: USR 6 MD5 I example@hotmail.com
S: USR 6 MDS S prefix
C: USR 7 MD5 S $md5(prefix + password)
S: USR 7 OK example@hotmail.com example%20user
S: MSG Hotmail Hotmail 367
MIME-Version: 1.0
Content-Type: text/x-msmsgsprofile; charset=UTF-8
LoginTime: 1726321960
EmailEnabled: 1
MemberIdHigh: 1
MemberIdLow: 2
lang_preference: 1033
PreferredEmail: example@hotmail.com
country: US
PostalCode: 
Gender: 
Kid: 0
Age: 
BDayPre: 
Birthday: 
Wallet: 
Flags: 1027
sid: 507
kv: 11
MSPAuth: AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA$$

C: SYN 8 5
S: SYN 8 5
C: CHG 9 NLN
S: CHG 9 NLN
C: CVR 10 0x0409 win 4.10 i386 MSMSGS 2.0.0083
S: CVR 10 2.0.0085 2.0.0085 1.0.0863
.. http://download.microsoft.com/download/msnmessenger/install/2.0/Win98/EN-US/mmssetup.exe
.. http://messenger.msn.com/
C: IMS 11 OFF
S: IMS 11 0 OFF
C: IMS 12 ON
S: IMS 12 0 ON
C: SND 13 anotheruser@hotmail.com 0x0409 MSMSGS
S: SND 13 OK
C: OUT

Client disconnects from server.
Server disconnects client.