instead of leaving coding agents to guess missing details from raw paper code, ReproBridge builds a standardized artifact (refined codebase, environment setup, launchers, reproduction guide) and has a separate Auditor check execution evidence. Across 1,029 tasks from 36 papers and four models, refined artifacts lifted mean success to 92.6%, cut downstream API spend 19.7%, and narrowed the cross-model spread from 21.6 to 3.9 points.