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: 6%. Bars are scaled to that peak, not to 100%.
Which agents
| Cursor Agent | Anysphere | 16 | 0.5% |
| Claude Code | Anthropic | 5 | 0.2% |
Verify it yourself
Sample commits that matched. Every one links to GitHub — check the trailers.
73b245fe[PYTHON][MINOR] Use a unique per-run rendezvous id for distributed torch tCursor Agentef6f78bc[SQL][MINOR] Bound nesting depth when converting protobuf Any to JSONCursor Agentca8e43ba[MINOR] Improve resilence on raw socket stream and steer people towards hiCursor Agentca8e43ba[MINOR] Improve resilence on raw socket stream and steer people towards hiClaude Code77f1e057[PYTHON][MINOR] Improve TorchDistributor log server provisioningClaude Code432adc74[MINOR][UI] Escape HTML when rendering error messages in the Web UI tablesClaude Code
What was excluded
| Commits in window | 3,267 |
| Merge commits removed | −0 |
| CI / dependency bots removed | −0 |
| Considered | 3,267 |
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/spark