Screen flicker on mac for claude code

[jussikuosa]

Issue Description

I'm experiencing a fair amount of screen flicker in ghostty that I haven't seen in mac terminal. The attached video is from claude code

ghostty_screen_flickering_smaller.mov

I've seen something similar when doing ctrl+r history completion in zsh+omz

Expected Behavior

in regular mac terminal, the screen remains smoother without flickering

Actual Behavior

screen flickers and in this case it seems to switch between the detailed transcript and the normal user mode

Reproduction Steps

-open ghostty with zsh+omz
-start claude code
-run agentic swarm to refactor a codebase

Ghostty Logs

-

Ghostty Version

Ghostty 1.1.3

Version
  - version: 1.1.3
  - channel: stable
Build Config
  - Zig version: 0.13.0
  - build mode : builtin.OptimizeMode.ReleaseFast
  - app runtime: apprt.Runtime.none
  - font engine: font.main.Backend.coretext
  - renderer   : renderer.Metal
  - libxev     : main.Backend.kqueue

OS Version Information

acos 15.6 sequoia

(Linux only) Display Server

None

(Linux only) Desktop Environment/Window Manager

No response

Minimal Ghostty Configuration

theme = dark:Builtin Solarized Dark,light:Builtin Solarized Light

Additional Relevant Configuration

No response

I acknowledge that:

• I have reviewed the FAQ and confirm that my issue is NOT among them.
• I have searched the Ghostty repository (both open and closed Discussions and Issues) and confirm this is not a duplicate of an existing issue or discussion.
• I have checked the "Preview" tab on all text fields to ensure that everything looks right, and have wrapped all configuration and code in code blocks with a group of three backticks (```) on separate lines.

[pluiedev]

Dupe of #8162 (and many more). TL;DR Ghostty is actually too fast and displaying in-between frames, as Claude is actually not updating the screen fast enough. Instead, it needs to implement a protocol known as "Synchronized Output" to let Ghostty know when it's safe to update the frame.