PartialCoding

Use AI coding tools on your own mature open-source repo

Tools: Cursor + Claude 3.5/3.7 (early 2025)

Setup, access, approval gate, failure notes
Setup / prompt
Randomized trial: 16 experienced maintainers, real issues, AI allowed vs. disallowed.
Access required
Developers' own repositories
HITL checkpoint
Developers fully in the loop
Outcome & failure notes
Developers were 19% slower with AI while believing they were ~20% faster. Time went to prompting, waiting, and reviewing. METR changed its study design in 2026, and later evidence is more mixed, so treat this as context-specific.
Evidence type
Randomized controlled trial

Source: METR · 2025-07-10 · Checked 2026-10-19