DeepSeek re-post-trains V4-Flash into an agent specialist
DeepSeek promoted V4-Flash to public beta as V4-Flash-0731 with MIT-licensed weights. The architecture did not change: 284B total parameters, 13B active, 1M context. The jump came entirely from post-training for coding, agents, reasoning and tool use.
Terminal Bench moved 61.8 → 82.7, DeepSWE 7.3 → 54.4 and Toolathlon 49.7 → 70.3, putting the cheap Flash build ahead of DeepSeek’s own Pro preview on every agent benchmark it publishes. Price stayed at $0.14/$0.28 per million input/output tokens.

WHY IT MATTERS
This was the week’s cleanest proof that post-training, not scale, is where agent capability is moving — a 13B-active model above its own much larger sibling at a fraction of the cost.
