Comment by thehamkercat
7 hours ago
Same with opencode and gemini, it's disgusting
Codex (by openai ironically) seems to be the fastest/most-responsive, opens instantly and is written in rust but doesn't contain that many features
Claude opens in around 3-4 seconds
Opencode opens in 2 seconds
Gemini-cli is an abomination which opens in around 16 second for me right now, and in 8 seconds on a fresh install
Codex takes 50ms for reference...
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If their models are so good, why are they not rewriting their own react in cli bs to c++ or rust for 100x performance improvement (not kidding, it really is that much)
Great question, and my guess:
If you build React in C++ and Rust, even if the framework is there, you'll likely need to write your components in C++/Rust. That is a difficult problem. There are actually libraries out there that allow you to build web UI with Rust, although they are for web (+ HTML/CSS) and not specifically CLI stuff.
So someone needs to create such a library that is properly maintained and such. And you'll likely develop slower in Rust compared to JS.
These companies don't see a point in doing that. So they just use whatever already exists.
Opencode wrote their own tui library in zig, and then build a solidjs library on top of that.
https://github.com/anomalyco/opentui
This has nothing to do with React style UI building.
Those Rust libraries have existed for some time:
- https://github.com/ratatui/ratatui
- https://github.com/ccbrown/iocraft
- https://crates.io/crates/dioxus-tui
Where is React? These are TUI libraries, which are not the same thing
1 reply →
and why do they need react...
That's actually relatively understandable. The React model (not necessarily React itself) of compositional reactive one-way data binding has become dominant in UI development over the last decade because it's easy to work with and does not require you to keep track of the state of a retained UI.
Most modern UI systems are inspired by React or a variant of its model.
Why does it matter if Claude Code opens in 3-4 seconds if everything you do with it can take many seconds to minutes? Seems irrelevant to me.
I guess with ~50 years of CPU advancements, 3-4 seconds for a TUI to open makes it seem like we lost the plot somewhere along the way.
Don’t forget they’ve also publicly stated (bragged?) about the monumental accomplishment of getting some text in a terminal to render at 60fps.
This is exactly the type of thing that AI code writers don't do well - understand the prioritization of feature development.
Some developers say 3-4 seconds are important to them, others don't. Who decides what the truth is? A human? ClawdBot?
Because when the agent is taking many seconds to minutes, I am starting new agents instead of waiting or switching to non-agent tasks
codex cli is missing a bunch of ux features like resizing on terminal size change.
Opencode's core is actually written in zig, only ui orchestration is in solidjs. It's only slightly slower to load than neo-vim on my system.
https://github.com/anomalyco/opentui
50ms to open and then 2hrs to solve a simple problem vs 4s to open and then 5m to solve a problem, eh?
Codex team made the right call to rewrite its TypeScript to Rust early on