A Nature Biotechnology report and accompanying analyses describe the discovery and engineering of bacterial retrons for precise genome editing. Authors used metagenomic screening to identify retron reverse transcriptases and repurposed retron systems to synthesize multicopy single‑stranded DNA templates in‑cell, enabling repair of large DNA stretches without double‑strand breaks. The approach could broaden gene‑editing capabilities for complex, multi‑mutation disorders and offer an alternative route to existing base‑ and prime‑editing platforms.