Claude Code's creator: 259 pull requests in 30 days, all written by AI
By Boris Cherny (Anthropic)Built and shared by Boris Cherny (Anthropic), not by me. Summarised from the public sources below. Check them before you rely on a number.
- Who
- Boris Cherny (Anthropic)
- Category
- Software development
- Source
- X · Web
- Dates
- Published 27 Dec 2025 · Found 17 Oct 2026
Boris Cherny, who started Claude Code as a side project at Anthropic, wrote on X that all of his code over 30 days had been written by Claude Code with Opus 4.5. The post became one of the most cited examples of agentic coding.
What they built
Cherny developed Claude Code itself using Claude Code as his only writing tool. The agent worked for minutes, hours and days at a time, kept running by so-called Stop hooks, while he steered and reviewed the work.
The result
In 30 days he landed 259 pull requests with 497 commits, 40,000 lines added and 38,000 removed. Every line was written by Claude Code + Opus 4.5.
Sources
OpenAI team shipped a product with zero lines of hand-written code
By Ryan Lopopolo (OpenAI)
A small OpenAI team spent five months building and shipping an internal beta of a software product where Codex wrote every line of code. Engineer Ryan Lopopolo describes how the engineers' job became designing the environment, the rules and the feedback loops the agents work inside, which he calls harness engineering.
Stripe's 'Minions' agents write more than 1,000 merged pull requests a week
By Stripe (Alistair Gray)
Stripe built its own coding agents, called Minions, that take a task from a Slack thread and deliver a pull request that passes CI and is ready for review. Each week more than a thousand merged PRs are written entirely by Minions; engineers review them but write none of the code.
Non-technical Meta PM builds and ships apps without writing code himself
By Zevi Arnovitz (Meta)
On Lenny's Podcast, Meta product manager Zevi Arnovitz shows his AI workflow, which lets a non-technical person build real products. He builds a new feature in his study app StudyMate live in the episode.
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