Adoption is broad. Many contributors are committing agent-authored work, which is what a real organisational rollout looks like.
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: 5.4%. Bars are scaled to that peak, not to 100%.
Which agents
| GitHub Copilot | GitHub | 19 | 2.5% |
| Claude Code | Anthropic | 2 | 0.3% |
Verify it yourself
Sample commits that matched. Every one links to GitHub — check the trailers.
20373450GH-51199: [CI] Limit concurrent PRs from new contributors (#51200)GitHub Copilot248d6037GH-51098: [Release] Update CHANGELOG.md as a post release task (#51117)GitHub Copilotb12755a1GH-47686: [Docs][Python] Split the Python Parquet docs into separate itemsGitHub Copilota769c291GH-45086: [C++] Fix heap buffer overflow in FillNullForward/Backward … (#5Claude Codec20a04a0GH-35806: [R] Improve error message for null type inference with sparse CSClaude Code
What was excluded
| Commits in window | 786 |
| Merge commits removed | −0 |
| CI / dependency bots removed | −26 |
| Considered | 760 |
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 apache/arrow