I'm always surprised that Python doesn't have as good TUI libraries as Javascript or Rust. With the amount of CLI tooling written in Python, you'd think it had better libraries than any other language.
One reason for the lack of python might be the timing of the TUI renaissance, which I think happened (is happening?) alongside the rise of languages like Go and Rust.
They also probably mean TUIs, as CLIs don't do the whole "Draw every X" thing (and usually aren't interactive), that's basically what sets them apart from CLIs.
It’s surprising how quickly the bottleneck starts to become python itself in any nontrivial application, unless you’re very careful to write a thin layer that mostly shells out to C modules.
Textual is A++. Feels a bit less snappy than Ink, but it makes up in all things with its immense feature-set. Seriously fun building apps of all kinds with this lib.
They started with Ink but have since switched to their own renderer:
> We originally built Claude Code on Ink, a React renderer for the terminal. [...] Over the past few months, we've rewritten our rendering system from scratch (while still using React).
React is just an abstraction of a State -> View function.
While not universally applicable, it's very convenient during development to focus on State without thinking about View, or focus on View without thinking about State.
The concept itself has nothing to do with the actual renderer: HTML, TUI, or whatever. You can render your state to a text file if you want to.
So the flickering is caused either by a faulty renderer, or by using a render target (terminal) that is incompatible with the UI behavior (frequent partial re-renders, outputting a lot of text etc.)
Thats the problem. Some developers want to avoid learning another programming language and use one for everything (including their technologies.)
Using TS, React here doesn’t make sense for stability in the long term. As you can see, even when they replaced Ink and built their own, the problem still exists.
There are other alternatives that are better than whatever Anthropic did such as Bubbletea (Go) or Ratatui (Rust) which both are better suited for this.
Maybe they were thinking more about job security with TypeScript over technical correctness and a robust implementation architecture and this shows the lack of it.
I’m a fan of Bubbletea, but it is significantly less ergonomic than React. Although I’d argue that if that starts to matter significantly, your TUI is probably too cluttered anyway and you should pare it down.
FWIW, Ink is working on an incremental rendering system: they have a flag to enable it. It's currently pretty buggy though unfortunately. Definitely wish Anthropic would commit some resources back to the project they're built on to help fix it...
https://github.com/anthropics/claude-code/issues/769
I locally patched the closed-source CLI npm package but it's not perfect. They would have to switch how their TUI is rendered on their side.
Apparently OpenAI Codex is rust+ratatui which does not have this issue.