Anthropic used mostly AI to build Claude Cowork tool

Anthropic’s newest productivity experiment, Cowork, is notable not just for what it does, but for how it was made. Cowork is essentially a version of the AI coding tool Claude Code for non-developers. And according to the company, much of Cowork was built by Claude Code itself, turning the AI into both the product and a key part of the development process.

Instead of writing software, users grant Claude access to a folder on their computer and ask it to perform real work, such as organizing files, drafting reports, compiling spreadsheets from screenshots, or cleaning up documents. Unlike a standard chat, Cowork operates with more autonomy. You assign a task, and Claude plans and executes it step by step, keeping you informed as it progresses.

Anthropic says that after launching Claude Code, it noticed users repurposing it for everyday tasks far beyond programming, from planning trips to managing personal data. That behavior directly inspired Cowork’s agentic design.

When asked on X how much of Cowork was built using Claude Code, Boris Cherny, Anthropic’s head of Claude Code, replied simply: "All of it."

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Cowork is launching as a research preview for Claude Max subscribers on macOS, with Anthropic emphasizing that this is an early step toward more agent-like AI tools.