Everything needs to change

Theo (t3.gg) argues, inspired by Karpathy, that agentic development demands a bigger IDE that orchestrates multiple projects, terminals, browsers, and agents — not smaller CLI tools.

• Karpathy’s post is the direct catalyst: CLIs like Claude Code and Codex are not the endpoint — we need to go bigger, not smaller.
• Current editors are shaped for one-project-at-a-time; agentic devs now run multiple codebases in parallel, breaking the per-project editor model entirely.
• VS Code’s per-project .vscode config was the feature that converted Theo in 2018, but it is now a liability when working across many repos at once.
• The mental cost of mapping terminal tabs, editor windows, and browser tabs across multiple active projects now exceeds the actual cost of building.
• tmux, built on libGhostty, combines real terminal and browser in named project spaces — closer to the vision, but still far short.
• T3 Code is Theo’s team’s early attempt: multi-project UI with embedded terminals per Julius’s design; browser pane and horizontal multi-chat are still missing.
• Theo draws an explicit parallel to TypeScript: full-stack type safety took years after TS adoption, and he hopes IDE rethinking moves faster given agentic pace.
• Atom was the first Electron project, spinning Electron out as a standalone framework; VS Code then outcompeted it with Microsoft’s engineering focus.

2026-03-20 · Watch on YouTube