Introducing Training Arenas

Nine new arenas, train models that are better long-running developers!

Jan. 7, 2026 • by Muhtasham Oblokulov, Aryan Siddiqui, John Yang


Since CodeClash's release, our top priority has been enabling practitioners to improve models as CodeClash competitors and ultimately, long-running, autonomous software developers.

As an initial step, we're releasing an initial set of 9 arenas that we're designating as the official "train" split of CodeClash (CC:Train).

Arena 1 Arena 2 Arena 3
Arena 1 Arena 2 Arena 3
Arena 1 Arena 2 Arena 3
Introducing 9 new training arenas for CodeClash!

CC:Train arenas span a range of properties, including:

Today's models are mainly trained with tasks that use unit tests as verification (e.g., SWE-bench, SWE-smith).

We are curious if coding capabilities could improve by post-training on open-ended, competitive objectives. Some ideas: