This is a Plain English Papers summary of a research paper called Axion 1.0 Trains Tool-Using Agents with Two SFT Stages and GRPO . If you like these kinds of analyses, you can find more AI and machine-learning research on AIModels.fyi or follow us on Twitter .

Axion 1.0’s three-stage recipe for agent training

Axion 1.0 trains agent foundation models with two supervised fine-tuning stages followed by reinforcement learning, omitting dedicated mid-training, direct preference optimization, and on-policy distillation. The central claim is that a compact pipeline can still support reasoning, tool use, and long-horizon interaction when its training tasks are carefully constructed and verified.

The first SFT stage targets self-contained reasoning: seed questions from subjects including mathematics, physics, and biology are transformed into harder problems, then strengthened when the base model solves them.…