A small group is using agents. Adoption has spread beyond one person but is not project-wide.
Assisted or autonomous
Assisted — a developer’s identity authored the commit and the agent added itself as co-author. The agent ran git commit during a working session, with a person there. Autonomous — a bot identity is the author, no human in the loop. Across the whole index, 93.7% of agent commits are assisted.
Agent share by month
Peak month: 1.8%. Bars are scaled to that peak, not to 100%.
Which agents
| Claude Code | Anthropic | 7 | 0.7% |
| Cursor Agent | Anysphere | 2 | 0.2% |
Verify it yourself
Sample commits that matched. Every one links to GitHub — check the trailers.
7d6483b0fix(rust): Use try_new in StructArray construction in polars-json (#27489)Claude Coded8a460cdrefactor: Bloat dispatch reduction (#28337)Claude Code6830ff27feat: Add suggestions in wrong api usage or mismatched column names (#2795Claude Code997ce5c1feat: Add ewm_sum and ewm_sum_by #28151 (#28215)Cursor Agent81db6a9ffix(python): Fix `DataFrame.write_database(..., if_table_exists="append", Cursor Agent
What was excluded
| Commits in window | 1,080 |
| Merge commits removed | −0 |
| CI / dependency bots removed | −8 |
| Considered | 1,072 |
Bots are excluded from the denominator entirely. Counting dependabot as “AI-written code” is the fastest way to produce a meaningless number.
How this was measured
Measured over February–August 2026, cloned directly. Detection is deterministic string matching against signatures agents write about themselves — no heuristics, no style analysis. Merge commits and CI bots are excluded from the denominator. The figure is a floor: squash merges strip trailers, so real usage is higher. Contributor counts are aggregate — no individual is named.
Run it yourself: npx qmmit-cli pola-rs/polars