The agent harness is the new IDE
1 min read across 234 words.
The agent harness is the new IDE.
That sounds grandiose until I look at my own behavior. VS Code used to be the place where software work happened: the project tree, the terminal, search, type errors, tests, notes, diffs, habits. Now those surfaces still exist, but they have slipped behind the agent. The desktop apps for Codex and Claude Code have become the primary environment, and the editor has become an implementation detail.
The important shift is not that an agent can write code. It is that the harness now holds the working context: the repository, the instructions, the shell, the browser, the review loop, the memory of what has been tried, and the ability to move from intention to patch to validation without forcing me to keep every intermediate state in my head. The old IDE optimized the human's direct manipulation of files. The new one optimizes delegation, inspection, and correction.
This changes the shape of craft. I still care about the same things: readable code, tight feedback loops, tests that mean something, source-of-truth boundaries, reversible decisions. But I increasingly express that craft as constraints and reviews around an agentic runtime rather than as keystrokes inside an editor. The skill is moving up a layer.
There is a strange intimacy to this. VS Code was where I lived with the code. Codex and Claude Code are where I now live with the work.