GTA V Co-op 0.9.3

A Network Script

Enables you to host or connect your game world to private hosted servers.

No This does not connect to rockstar games GTA:online servers 

This is completely separate. 

you can not and should not be banned in GTA online for this 

as it is completely single player based

F9 on keyboard brings up Client Window

for you to initiate the next step
be it you host your own game or join one.

Here I joined a server

Server Browser

A feature you may miss if you like to join specific servers manually

similar to SA:MP and games allowing you to host/join private servers

Player List 

Even complete with listing all connected players to the current season

Server Messages

Server tells you when you have successfully connected to a session

 As well as when other players join or leave the session

And alot more..

As the name of this mod Suggest

This is Co-op

which means you can run around with friends

 and do just about anything as you would be able to do in single player

Have a watch of me Testing this mod

GTA:Online?

Q.

Can You Get Banned using this? 

A.

No

as long as you dont try to use this while connected in GTA: online. 

you shouldn't have a problem

Plus it would be really dumb to use a multiplayer mod while connecting to another multiplayer session. but since people are stupid enough to try it. 

be aware! doing that type of dumb shit may get you banned.

Personally I have 2 GTA V folders. 

1 for modding and all you see here and

 another for GTA online 

anyone with GTA V can use this script

its still pretty early in development 

but pretty good for what it is and all its features.

Like the early days of SA:MP

you had bugs and bad sync

this is similar, but

 development is quicker

Click this green button
 for more info and download

Installation Guide 

How to install GTA Co-op