Thirteen years is a long time to wait for a video game. Apparently, it's long enough for someone just to say, "Fine, I'll do it myself."
Ziwen Xu, a 25-year-old founder of AI agent startup Hyperecho, kicked off the project with a post on X. "Day 1 of building GTA 6. Still feels fake typing that out," he wrote, and upgraded to Claude Max 20x specifically for the project. The first footage was exactly what you'd expect: a blue box wandering around an empty 3D plane. Not much, but every game starts somewhere.
He spent a week ignoring everyone who told him to switch engines before finally caving on day seven and migrating from Godot to Unreal Engine. The project, dubbed GT-Caliber, runs on daily public updates and an open GitHub repo, with AI agents continuously looping, taking community feature requests, and generating pull requests in real time. Perhaps unsurprisingly, there's no publisher, and no studio budget. Ziwen seems to be relying on whoever shows up for the project.
The project has moved surprisingly fast, but also chaotically. Within the first week, Ziwen switched engines three times, finally landing on Unity. He explained that getting on a "real engine" was crucial to make a triple-A game. Of course, AI tools handled a significant portion of the asset creation, generating Rockstar-style news clips, characters, cars, and buildings. Almost everything was created through what Ziwen calls "vibe coding" with a loop of AI agents.
The progress has been genuinely wild for nine days of work. By day three, NPCs were walking around, cars on the road, working weapons, and phones with Instagram in them. By day seven, a whole neighborhood with streets had appeared on screen, even though the AI accidentally built Los Angeles instead of Miami. Ziwen called it the first time the thing looked like an actual GTA game rather than a prototype.
The timing of the project makes for a funny backdrop. Rockstar officially revealed the GTA 6 pre-order date today: June 25, 2026, alongside the game's official cover art. The cover follows the series' familiar collage style, featuring Jason Duval and Lucia Caminos front and center. The game still launches on November 19 on PS5 and Xbox Series X/S.

So Ziwen has about five months, and his project is making progress day by day. On the flip side, Rockstar had 13 years and thousands of people working on GTA 6. Whether "GT-Caliber" ships anything resembling a real game or just becomes the most entertaining dev diary on the internet, it's worth keeping an eye on.




