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About

In March 2020, Rockstar replaced Grand Theft Auto IV and Episodes from Liberty City with GTA IV: Complete Edition. Games for Windows Live was removed, and multiplayer was removed with it. There was no replacement.

The game itself still works. You can buy it, install it and drive through Liberty City. You just cannot do it with other people.

HappinessMP changes that.

What it is​

HappinessMP has two parts. One is the mod you install on your own PC. The other is server software, which someone else runs. You pick a server, connect to it, and drive through Liberty City at the same time as everyone else who is on it.

It is not a remaster and not a total conversion. Your game stays where it is, and singleplayer keeps working.

How it works​

GTA IV shipped with a working multiplayer mode. Rockstar switched off the service around it, but the code underneath is still in the game. HappinessMP uses that code instead of replacing it.

That has two effects. Traffic, pedestrians and police behave the way Rockstar built them to, because it is still Rockstar's code running them. And sync is as good as the game managed on its own.

The mod follows the current build of GTA IV, so there is nothing to downgrade. The client is written in modern C++ for Windows 10 and 11.

Servers make the game​

Rockstar's own modes are gone: the deathmatches, races and ranked lobbies from 2008. HappinessMP does not bring them back. It ships with no game modes at all.

Servers write their own instead. A server decides what spawns, what the rules are, and what happens when you die. One server is a race through Bohan. The next is a roleplay city with jobs. The next is thirty people, thirty helicopters and no plan.

So the interesting part is not what we build. It is what server owners build on top of it. The server manual covers how.

What it is not​

  • Not affiliated with Rockstar Games or Take-Two. This is a fan project.
  • Not a free copy of the game. You need your own GTA IV: Complete Edition, the version currently sold on Steam and the Rockstar launcher. HappinessMP ships no game files and never will.
  • Not finished.

Where it stands today​

The first public playtest was on 23 January 2023. Since then the mod has become stable enough that crashes are the exception, not the evening.

Scripting has come the furthest. Servers can script almost anything they want, including streaming their own custom content into the game. The clearest limit today is how many players one server can hold, and raising that is the thing I get asked about most.

About ten servers are online right now. They run freeroam, racing, roleplay, and a few things that are harder to label. Player numbers are still small: ten people on a good evening. That is the honest figure. Turn up now and you will know everyone by name within a week.

There is no roadmap. I work on whatever is most needed, or whatever I feel like that week.

Who builds it​

Me, alone. Every line of it.

I grew up on SA:MP. It was most of my childhood. Years later I went looking for the same thing for GTA IV. IV:MP had already stopped. Then I tried MultIV, then CitizenMP:IV, and both were discontinued as well. At that point there was no active multiplayer project left for GTA IV, so in mid-2022 I started building one.

Liberty City is worth the effort. No other city in the series has that atmosphere, and almost nothing has been built on top of it.

One developer means things move slowly. It also means this project is not going to disappear because a team lost interest.

Where to find us​

Everything happens on Discord. Updates, servers looking for players, bug reports, questions about scripting: all of it in one place.

Come and say hello. It is also where people argue about whether IV handles better than V. It does.