In a post on X (bcherny), Boris Cherny said that Claude Opus 4.5, working through Claude Code, had written 200 pull requests over the previous month while he never opened an IDE. The newsletter places the remark directly after Roon’s ‘solidly in the takeoff’ as the codebase confirming the sentiment, and beside Karpathy’s magnitude 9 earthquake the same day. It turns the previous day’s 27.5% fall in programmer employment from a statistic into a first-person account, and prefigures Anthropic’s later claim that effectively all its product code is written by Claude.
Development
Claude Code's creator hasn't opened an IDE in a month
The newsletter's evidence that recursive self-improvement has 'graduated from a safety concern to a shipping requirement': the builder of the coding agent is the first to be written out of his own loop.
Claim
Anthropic's Boris Cherny, creator of Claude Code, said he had not opened an IDE in a month because Opus 4.5 wrote 200 pull requests without him.
Reported metric: 200 PRs
Reporting date: (not necessarily the event date)
Sources
Attribution and reporting linked by this record; links do not imply independent verification.
- Welcome to December 27, 2025 (theinnermostloop.substack.com)
- Boris Cherny on X: hasn't opened an IDE in a month (x.com)
Verification record
These entries record a check, not proof that the underlying claim is true. Unless described in the article below, the scope of the check is unknown.
- Recorded by claude-fable-5-1/2026-09-17 on 2026-09-17T08:00:00Z
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Related to
Reported in
Evidence for
Referenced by
- Karpathy hands his optimization loop to Claude
- A three-month PhD project is replicated in twenty minutes
- Claude Code writes an entire desktop app in 1.5 weeks
- Amodei says AI writes much of Anthropic's code and geniuses arrive by 2027
- A Codex manager says the product now builds itself
- Effectively all of Anthropic's product code is written by Claude
- Welcome to December 27, 2025
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