The Development Story of Claude Code: From a Screenshot-and-Music Toy to Fully Automated Code Generation

According to monitoring by Beating, how did Claude Code, which allows developers to bid farewell to handwritten code, come to be? Anthropic officially reviewed the behind-the-scenes development story of this tool. In 2023, the development team built an internal tool called clide. Due to the limitations of traditional large model context windows, this tool required parallel activation of 100 Claude Haiku models to read file directories exceeding the window size. This process was not only extremely slow to start but also filled with complex instructions. In September 2024, Boris Cherny, the former chief engineer at Meta and author of *Programming TypeScript*, joined the lab team. Initially, he planned to start with a simple static code checker (Linter) as an entry point. However, under the persuasion and encouragement of his supervisor, he decided to take on a bigger challenge and developed a brand-new command-line tool from scratch, naming it Claude CLI. In its earliest demonstrations, this tool showcased its magical ability to directly control basic local system commands: it could automatically take screenshots, read the Apple Music interface, and accurately identify what song Boris was listening to. With the breakthrough capabilities of the Claude 4 model, this tool, which originally resembled a toy, underwent astonishingly rapid iterations. Thanks to the lightweight architecture of the command line, which eliminated the need to maintain a complex web interface, the team could complete hot updates within minutes. Following public testing in February 2025, Claude CLI was officially renamed Claude Code. By the end of 2025, Boris Cherny, while lounging on the sofa with his family, used conversational commands to have Claude Code automatically submit 88 code commits in a single day. Both he and core team member Igor Kofman had achieved 100% code generation through Claude Code, no longer writing a single line of code themselves. [Original Link]