CodeWalker is essentially to GTA map modding what a level editor is to a Source mod scene. It's the program that allows you to actually see what you're working with. Before CodeWalker, editing GTA's RAGE map files involved hand-editing XML and crossing your fingers. CodeWalker turned that into a graphical editor, and the scene has expanded since.

We intentionally keep this page brief. It serves as a glossary entry for the many articles on this site which reference CodeWalker in passing - if you're reading one of those articles and wondering what CodeWalker is, this is your answer.

What CodeWalker is

CodeWalker is an open-source graphical editor for the asset files used by the RAGE engine of GTA V. It can directly render the GTA V map, fly around it like a flycam, view individual files that make up the map, make edits to them, and export them back out into a usable format.

The map data that makes up GTA V's world is contained within YMAP files. These are XML-derived files which detail where objects are placed, at what rotation, and with which variants. YMAP, YMT and YDR are the file extensions you'll see most when modding maps. CodeWalker supports them all, along with ancillary tools.

What CodeWalker actually lets you do

View the map. Drop objects from the vanilla GTA V prop library onto your map. Move and rotate existing objects. Insert or swap out MLO interiors. View collision and lighting data on individual pieces of the map. Export your edits into a YMAP file ready to be placed in the modded game.

What CodeWalker doesn't do, on its own, is create new 3D content. Custom buildings, interiors and assets must still be authored in 3ds Max, Blender or Maya, then exported with plugins, then hooked into the game via CodeWalker. The division is similar to other 3D modding pipelines - modelling app, level editor, packager.

Where CodeWalker came from

CodeWalker is not a Rockstar tool. It is an open-source program made by the community. It began life as a much simpler asset viewer many years ago and eventually evolved into the fully fledged editor it is today - and it's still being developed.

We won't name names, but the small team who helps keep CodeWalker going does amazing work. The reverse-engineering effort that lets CodeWalker read and write the RAGE engine's map formats should not be understated. Most of what the modern-day GTA 5 modding scene takes for granted relies on CodeWalker staying up to date.

How CodeWalker fits into the wider toolchain

OpenIV takes care of the archive layer - opening .rpf files which Rockstar uses to package up their assets. CodeWalker takes care of the map layer - reading and writing map/world data. 3ds Max or Blender plugins take care of 3D content creation. ScriptHookV takes care of runtime scripts. The four together comprise the GTA 5 modding stack.

Back in 2024 or 2025, if you wanted to learn map modding from scratch, the recommended path was: learn OpenIV, then the file structure, then CodeWalker for the map editing itself, then 3ds Max or Blender for asset authoring. That learning path has remained consistent for years.

What this means for GTA 6

If the GTA 6 map file format is a recognisable evolution of GTA V's, then CodeWalker is already primed for expansion. But if its format has been substantially redesigned, the editor must either be rewritten or replaced. At this point we don't know which scenario is correct. Either way, it matters, because the gap between 'no tool exists' and 'tool exists' is when serious map modding becomes possible.

Realistically, we should see a CodeWalker successor within the first year following GTA 6's PC release. If the format is similar, we can probably expect it sooner; if it isn't, it may take longer. See the modding tools expectations piece for more on the general question of 'when'.