The Shift That Already Happened

A year ago, if you wanted AI help writing code, you opened your editor and used whatever was built in. Copilot, Cursor, Windsurf. They've gotten genuinely capable. Agent modes that make multi-file changes, run commands, iterate on errors. These aren't just autocomplete anymore. But something else was gaining traction at the same time, and it's quietly changing how serious AI-assisted development actually works. The CLI agents Claude Code, OpenAI's Codex CLI, OpenCode, and others work directly in your terminal. They operate in your actual development environment with full access to the filesystem, your shell, your toolchain. They read your codebase, create files, run tests, fix what breaks, and iterate until the job is done. Editor agent modes can do a lot of this too. The difference isn't really about what the agent can do in theory. It's about what model is doing the work and what it costs you to use it. The model economics Every tool in this space is grappling with the same problem: