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: 56.7%. Bars are scaled to that peak, not to 100%.
Which agents
| Claude Code | Anthropic | 159 | 32.4% |
| GitHub Copilot | GitHub | 27 | 5.5% |
| Devin | Cognition | 1 | 0.2% |
| Cursor Agent | Anysphere | 1 | 0.2% |
Verify it yourself
Sample commits that matched. Every one links to GitHub — check the trailers.
fc22202cci: bump Apache ZooKeeper to 3.9.6 and bound download retries (#21099)Claude Code76f3e844cache: remove write-only timestamp from LRUCache entries (#21080)Claude Codea7a96c44feat(s3): use transfer manager for parallel S3 downloads during restore (#Claude Code35daf77fvtorc: replace --cells-to-watch with --cells-no-recovery (#20022)GitHub Copiloteccf6ee0Preserve Materialize target data on cancel (#20823)GitHub Copilot15366bf4mysqlctl: prevent closeBackupFiles from cancelling context on successful fGitHub Copilot7c9e1486VReplication: LookupVindex streams must not follow TABLES journals (#20917Devin4425351cApplySchema: add session variable options (#20654)Cursor Agent
What was excluded
| Commits in window | 639 |
| Merge commits removed | −0 |
| CI / dependency bots removed | −149 |
| Considered | 490 |
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 vitessio/vitess