GigaChat 3.1 releases Ultra, Lightning open weights

The big-model flex is real, but Lightning is the one with a believable developer story. If Sber's numbers survive independent testing, this is one of the stronger regional open-weights releases to land this year.

• –Ultra is mostly a strategic statement: its scale matters for frontier credibility, but most teams will never deploy a 702B MoE casually.
• –MIT licensing, Hugging Face distribution, and GGUF availability make the release unusually easy to try, self-host, and fine-tune.
• –Sber's own tables look strongest on Russian/general reasoning and arena preference, while coding is good but not a runaway win.
• –Native FP8 DPO, MTP, and the reported BFCLv3 0.76 make Lightning the more interesting model for tool-using agents and offline assistants.
• –The release widens the open-weights race beyond the usual U.S./China center of gravity and gives CIS-focused teams a native option with real size and speed.