longcrafter-b1e67be6·1 events·first seen Aliases: LongCrafter
LongCrafter is a structured framework for synthesizing long-context supervised fine-tuning data, addressing limitations of prior approaches including narrow task coverage, low difficulty, and lack of faithfulness supervision. The system uses a hierarchical 32-task taxonomy and constructs explicit evidence graphs modeling cross-paragraph dependencies to generate grounded instruction-response pairs. Models fine-tuned on LongCrafter data outperform SFT baselines and official post-trained models on LongBench, LongBench v2, and LooGLE for both Qwen2.5-7B and LLaMA-3.1-8B, with notable gains on high-difficulty tasks and improved robustness to the 'lost in the middle' problem.