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Takayuki Kawazoe
Takayuki Kawazoe

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64% of Our Merged PRs Were Written by AI — 2,424 PRs in 3 Months

Three months ago, a new "coworker" joined our GitHub organization. It never complains, works through the night, and occasionally goes home mid-task when its Spot instance gets reclaimed.

Last week I ran the numbers, and they were wilder than I expected.

64% of our merged PRs were written by AI

Between April 8 and July 6, 2026, our org's ten main repositories merged 3,781 pull requests. Of those, 2,424 (64%) came from branches created by AI agents.

The breakdown:

Type PRs What it does
Task-execution agents 859 Reads a Notion ticket, implements, tests, opens a PR, gets it merged — end to end
Maintenance bots 1,413 Doc sync and periodic housekeeping, quietly
Auto-fix agents 108 Watches Sentry, sends a fix PR when production breaks
Other agents 44 Odd jobs

Humans (effectively 2–3 of us) do reviews and direction. The hands on the keyboard are mostly AI.

Median time from "PR opened" to "merged": 2 minutes

For the 859 task-agent PRs:

  • Median: 2 minutes
  • p75: 9 minutes
  • 93% merged within an hour

"Who reviews a PR in 2 minutes?" — another AI does. When a PR opens, an AI code reviewer files findings with severity levels, CI runs, and on approval the PR auto-merges. Humans watch the results scroll by in Slack.

To be honest about the metric: this clock starts after the agent has already implemented and passed local verification. Still, from "ticket marked Ready" to "merged," you can brew a coffee and it's done before you're back.

Of course, it breaks in hilarious ways

So this doesn't read like a suspicious success story, here are real incidents:

  • Sudden resignation: agents run on Spot instances. When one is reclaimed mid-task, all that's left is a note reading failed at step ''. Reason: (empty)
  • Fake Done: the agent reports "Completed!" — there is no PR. There is also no one to interrogate
  • AI traffic jam: an AI-authored PR waits for an AI review to be merged by an AI, and another AI merges into the same file first
  • Time-bomb tests: an agent hardcoded a date into a test; 90 days later it detonated and blocked every PR in the repo

Each of these became its own postmortem article. The incident pipeline doubles as a content pipeline.

The machinery

We run this on Codens, our own family of AI dev-automation products:

  1. Green turns a conversation into a structured PRD
  2. Purple picks up tickets and runs agents: implement → verify → PR
  3. Orange auto-reviews every PR (with security audit)
  4. CI + approval → auto-merge
  5. Production error? Red detects it and sends a fix PR
  6. Blue handles QA and E2E

Yes, this whole article is a dogfooding report for our own product. But every number above is measurable via the GitHub API.

What's left for humans

After three months, the human jobs are:

  1. Deciding what to build — ticket quality is everything; vague tickets get vaguely implemented
  2. Designing verification — "tests pass" is not enough; agents will happily cut corners unless you assert file existence and forbidden patterns
  3. First-response when things break — and the incidents become blog posts

It feels less like "AI taking our jobs" and more like "suddenly managing a direct report who files 2,400 PRs a quarter." Management is hard.


Codens has a 14-day free trial (no credit card): codens.ai

Even adopting just Red turns "3 AM Sentry alert" into "a fix PR waiting for you at breakfast."

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