Tencent just released Hy4 Preview: a 770B-parameter open-source model with 49B active parameters and a 1M-token context window.

The most interesting part is its agentic research capability. Tencent says Hy4 coordinated several Codex sessions in parallel, evaluated their results and adjusted the research direction, outperforming Codex working alone across eight benchmarks.

Hy4 is aimed at long-horizon coding, multi-file office work and scientific research.

In sum: a solid, good release. A few months ago this would be absolute sota.