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: 15.8%. Bars are scaled to that peak, not to 100%.
Which agents
| GitHub Copilot | GitHub | 4 | 1.7% |
| Claude Code | Anthropic | 4 | 1.7% |
| Cursor Agent | Anysphere | 2 | 0.8% |
Verify it yourself
Sample commits that matched. Every one links to GitHub — check the trailers.
3a0661d7Don't construct a locale when formatting year_month_day (#4940)GitHub Copilote91e9276Don't let ADL pick to_string_view (#4938)GitHub Copilote5d13d82Make nolocale-test actually disable locale (#4939)GitHub Copilota3897572Remove the '0' chrono padding modifier from the docs (#4917)Claude Codee589a16eLook up sparse enum identifiers in a hash table instead of a linear searchClaude Codee27cc20bFormat enums annotated with fmt::as_identifiers (requires C++26 reflectionClaude Code1f0533a9Pin clang-20 installCursor Agente48f8a90Pin clang-format installCursor Agent
What was excluded
| Commits in window | 245 |
| Merge commits removed | −0 |
| CI / dependency bots removed | −8 |
| Considered | 237 |
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 fmtlib/fmt