1. 📘 Topic and Domain: The paper focuses on agentic mid-training for software engineering, specifically developing large language models that can autonomously navigate, edit, and test complex code repositories.
2. 💡 Previous Research and New Ideas: The paper builds on existing post-training approaches like SFT and RL for code agents, but proposes a novel "agent-native mid-training" paradigm that uses contextually-native trajectories (preserving complete information flow) and environmentally-native trajectories (from actual tool invocations) to instill foundational agentic behaviors earlier in training.
3. ❓ Problem: The paper addresses the distribution mismatch between static training data (showing only final code outcomes) and the dynamic, interactive nature of real software development where agents must iteratively navigate, edit, and test code based on feedback.
4. 🛠️ Methods: The authors synthesize two types of agent-native data from GitHub PRs: contextually-native trajectories (68.6B tokens) that reconstruct complete workflows, and environmentally-native trajectories (3.1B tokens) from actual Docker environment interactions, then perform mid-training on Qwen2.5 base models followed by supervised fine-tuning.
5. 📊 Results and Evaluation: On SWE-Bench Verified, their 32B and 72B models achieve 56.1% and 58.5% resolution rates respectively, surpassing the previous KIMI-DEV baseline while using less than half the mid-training tokens, with additional improvements on general code generation and scientific benchmarks.