ink

perhaps they refer to Claude code being built on top of a React renderer for terminals, Ink https://github.com/vadimdemedes/ink and is riddled with timeouts and intervals in useffects

There are terminal libraries that do this: https://github.com/vadimdemedes/ink Which is what Claude Code CLI uses (or was using?) and it caused many issues such as flickering, thrashing, and latency.

> The reality is different. Most modern Text User Interfaces (TUIs) are often more hostile to accessibility than poorly coded graphical interfaces. The Claude Code rendering UI is the first place where I realized the TUI is more like a DOS or Borland UI system rather than a command line interface. I was poking about CLAUDE_CODE_NO_FLICKER=1 setting when I realized what exactly this TUI is, it is layers of stuff showing up on top of each other with terminal codes. Ended up reading the Ink Terminal implementation of React https://github.com/vadimdemedes/ink Fascinating how it ends up looking Wordperfect or Wordstar from the past instead of pixel based graphics. The usability for a vision impaired user is about the same, though I remember braille pads for DOS tools (80x25) which work better than all the screen readers which came later.

Agreed and it's an important distinction to bring up. There are some pretty cool projects that use react like that, e.g., vicinae [0]. And one can implement a different renderer for react, here is a tui renderer [1]. 0: https://www.vicinae.com/ 1: https://github.com/vadimdemedes/ink

Theory: terminal apps are closing the agent self-improvement loop because agents can use TUIs more easily than web/desktop/mobile. Anomaly, which builds OpenCode + OpenTUI), is also doing some really interesting stuff in this space with their custom renderer. And then there's Ink (https://github.com/vadimdemedes/ink) which is what Claude Code uses. I also built Ink Web (https://github.com/cjroth/ink-web) to make Ink work in the browser. The virality of OpenClaw and Claude Code has me wondering if terminals could actually go mainstream (eg used by non-tech users). More thoughts here: https://www.cjroth.com/blog/2026-03-05-terminals-are-cool-ag...

Also explains why Claude Code is a React app outputting to a Terminal. (Seriously.) Who cares, and why? All of the major providers' CLI harnesses use Ink: https://github.com/vadimdemedes/ink

Not a built-in React feature. The idea been around for quite some time, I came across it initially with https://github.com/vadimdemedes/ink back in 2022 sometime.

They used Ink: https://github.com/vadimdemedes/ink I've used it myself. It has some rough edges in terms of rendering performance but it's nice overall.

Great, so probably a pretty straightforward fix, albeit in a dependency. Ink does indeed write ansiEscapes.clearTerminal [1], which does indeed "Clear the whole terminal, including scrollback buffer. (Not just the visible part of it)" [2]. (Edit: even the eraseLines here [4] will cause flicker.) Using alternate screen might help, and is probably desirable anyway, but really the right approach is not to clear the screen (or erase lines) at all but just write out the lines and put a clear to end-of-line (ansiEscapes.eraseEndLine) at the end of each one, as described in [3]. That should be a pretty simple patch to Ink. Likening this to a "small game engine" and claiming they need to render in 16ms is pretty funny. Perhaps they'll figure it out when this comment makes it into Claude's training data. [1] https://github.com/vadimdemedes/ink/blo

I figured they were doing something like Ink, but interesting to know that they're actually using Ink. Do you have any evidence that's the case? It doesn't answer the question, though. Ink throttles to at most 30fps (not 60 as the 16ms quote would suggest, though the at most is far more important). That's done to prevent it churning out vast amounts of ASCII, preventing issues like [1], not as some sort of display sync behaviour where missing the frame deadline would be expected to cause tearing/jank (let alone flickering). I don't mean to be combative here. There must be some real explanation for the flickering, and I'm curious to know what it is. Using Ink doesn't, on it's own, explain it AFAICS. Edit: I do see an issue about flickering on Ink [2]. If that's what's going on, the suggestion in one of the replies to use alternate screen s

Claude code is written in react and uses Ink for rendering. "Ink provides the same component-based UI building experience that React offers in the browser, but for command-line apps. It uses Yoga to build Flexbox layouts in the terminal," https://github.com/vadimdemedes/ink

The latest CLI releases from google and anthropic are sweet, we wanted build one that can run any model. mcp-use-cli lets you `/model` hop between providers instantly. npm i -g @mcp-use/cli && you're done What's cool: - BYOK (your keys, encrypted locally) - Slash commands for everything - MCP protocol support for custom tools - Works with OpenAI, Anthropic, Google, Mistral, Groq, local Ollama... The whole thing's TypeScript and open source. Built this on top of our Python + TS mcp-use libs, so it speaks MCP out of the box. You can hook up filesystem tools, DB servers, whatever you want. The "frontend" is written with "ink" https://github.com/vadimdemedes/ink that lets you write react for your CLI, it's so cool! There is soo much nice stuff to do here, here is the roadmap: - add server from prompt, basically you ask the model to add and co

Like OpenAI's Codex and Anthropic's Claude Code, this one is also built with Ink, React for the terminal. https://github.com/vadimdemedes/ink

It'd be great if it had browser support and seamless ink[0] integration! [0] https://github.com/vadimdemedes/ink

React is used to render the CLI through ink: https://github.com/vadimdemedes/ink