One person is driving this. The headline number reflects a single contributor's workflow, not a project-wide shift.
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: 77.1%. Bars are scaled to that peak, not to 100%.
Which agents
| Claude Code | Anthropic | 774 | 54.7% |
| GitHub Copilot | GitHub | 1 | 0.1% |
Verify it yourself
Sample commits that matched. Every one links to GitHub — check the trailers.
518f2a3cDOC: require human-written comments and specific AI disclosure (#66767)Claude Code89b16816BUG: MultiIndex.get_locs regressions in the vectorized list-like path (GH#Claude Codef040cfd3BUG: UTC to local conversion wrapped int64 silently (GH#66550) (#66753)Claude Codec6ee3150DOC: Fix invalid Sphinx cross-references in older whatsnew RST files (#644GitHub Copilot
What was excluded
| Commits in window | 1,493 |
| Merge commits removed | −0 |
| CI / dependency bots removed | −79 |
| Considered | 1,414 |
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 pandas-dev/pandas