Epic put the UE6 source public on GitHub last month at State of Unreal, about a year and a half before Early Access at the end of 2027. That’s a lot of progress sitting in public commit history that’s easy to miss if you’re not reading diffs every day.
I started pulling the weekly commit activity by engine module the week it went public, and it turned into a small tool: mainradar
It scans Epic’s public commit activity every Monday and provides three views:
- Discover (all ~1,047 active modules ranked by recent churn)
- Delta (how far each branch has moved)
- Spotlight (the 8 biggest movers of the week with a plain-language note on what changed).
Current state as of the latest scan: Scene Graph, the Verse-based one, is churning hardest, close to 1,000 files changed. EditorInteractiveToolsFramework is being decoupled from UnrealEd, a real architectural shift. PCG, Sequencer and Niagara are also seeing steady movement.
The original post I made about UE6 going public got a retweet from Tim Sweeney, which is a big part of why I kept building this out.
It’s free, no account needed: https://mainradar.munduscreatus.be
Would genuinely like feedback, especially on what other views or module groupings would be useful.
Week 3 is up. Slower week on ue6-main by volume (622 files vs 1,074 last week), but Epic emptied the Blueprint circular-dependency allowlist (KismetCompiler is now folded into BlueprintGraph), renamed revision control to “Lore”, and added a live status page to the Unreal Build Accelerator. I also reworked two pages this week: Delta is uncapped now (a full per-module breakdown on every branch pair) and Spotlight ranks by interest, so the smaller finds surface alongside the big refactors.
Week 4 is in!
Cascade was switched off by default one day after the UE6 source went public, and last week a new converter plugin appeared in the tree to facilitate easier transitioning to the new defaults. First commit: 85 files. It includes a commandlet that batch-converts entire folders of Cascade assets headlessly and writes a pass/fail report with before and after screenshots.
Also: the Mass entity framework had its highest-activity week since January (a MassCore foundation layer is forming), and Epic renamed its experimental serialization prototype from PlainProps to Ness.
Weekly update. On ue6-main this week: 3,204 distinct files across 960 commits, down from 5,437 the week before.
Epic is building the surface an external AI agent drives the editor through over MCP. Four new toolsets are in the tree at week close, covering geometry primitives, undo history, behavior tree authoring, and a console toolset that works at cooked runtime.
One correction to last week’s post: the real figure was 5,437 files, not 3,381.
