Install the ChatGPT and Codex Desktop App Declaratively on NixOS

I wanted to use the ChatGPT/Codex desktop application natively, which worked on NixOS with one command: NIXPKGS_ALLOW_UNFREE=1 nix run --impure github:numtide/llm-agents.nix#chatgptThat was temporary testing, but it was not how I wanted to keep it. My workstation is configured declaratively. If an application becomes part of my normal workflow, I want to put it in the NixOS configuration - not hidden inside terminal history as a command, which would be difficult to remember later on. ...

September 15, 2026 · 6 min · Ruhani Rabin