System for Communication
in Realtime" - the internal project name
(as opposed to the external marketing name) used to identify Instant Messenger
The protocol described in this documentation is used in ICQ and AIM. ICQ was bought by AOL and
after that they initiated merging these services. ICQ client started using the OSCAR protocol
and ICQ developers named this protocol v7. I think this is wrong because this number is used
to identify direct connection "rendezvous" protocol version. As I said before, the client-to-server
protocol is named "OSCAR" and there is no icq v7, icq v8, nor icq v9. AOL programmers just added
the 0x15 family for compatibility with old ICQ server database engine and begin use uins as
I tried to gather as more details about OSCAR as possible. This
documentation set was written for both AIM and ICQ IM services. Here is the
list of links to information with short descriptions:
|| Protocol basic info. FLAP/SNAC/TLV formats, etc
|| Detailed authorization, login and services setup description
|| List of known services and their SNACs with links to detailed info
|| Information about various packet sequences (e.g. search)
|| User classes, status types, message types, message flags, etc...
|| Changes that was made in these docs.
|| List of the people who helps me with these docs
|| Protocol specification terminology
|| List of unknown SNACs I'm looking info for
|| Download this documentation in a zip archive
Disclaimer: This documentation set and the author are in no way affiliated with
Mirabilis (AOL). No reverse engineering or decompilation of any AOL/ICQ
code took place to make this documentation. AIM is a registered trademark of
America Online, Inc. ICQ is a registered trademark of ICQ Inc.
Attention: This is not official OSCAR specification - USE IT AT YOUR OWN
RISK. I don't earn money for this work, I'm only have some fun. Please do not
send me a letters like "This is all shit. Goodbye", but feel free to tell me
about missing info and about bugs.
You always can find fresh copy of this documentation set at website
Please, please, please, if you have protocol information not listed here or you found a bug in
documentation (protocol bug, syntax/grammar error or obfuscated info)
send it to me with "oscar_info"
string in subject field or you can send it to
icq-devel mailing list.
P.S. I know my English is hard to read so I'm looking for English-speaking man
who could help me with this problem.