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: 62.7%. Bars are scaled to that peak, not to 100%.
Which agents
| GitHub Copilot | GitHub | 2373 | 52.3% |
| Claude Code | Anthropic | 6 | 0.1% |
Verify it yourself
Sample commits that matched. Every one links to GitHub — check the trailers.
64878f52Replace CoreCLR PAL wait subsystem (#132927)GitHub Copilot0554cde3JIT: Keep intrinsic-only loops fully interruptible (#133884)GitHub Copilot9b84671e[mono][llvm] Fix malformed uaddlp/saddlp intrinsic declarations (#132744)GitHub Copilot25f20c2fAdd regression test for expired self-signed trusted chainClaude Code4d84d0eaEscape C# keyword identifiers in OptionsValidator generated code (#130415)Claude Code4aa41b73[JSON] Fix source generator serializing null byte[] as empty string (#1298Claude Code
What was excluded
| Commits in window | 4,643 |
| Merge commits removed | −9 |
| CI / dependency bots removed | −101 |
| Considered | 4,533 |
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 dotnet/runtime