The UI layout appears to be broken when interacting with the agent. #16859

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1. fenggeHu

   added

   bugSomething isn't workingSomething isn't working

   on Mar 10, 2026
2. github-actions

   assigned

   kommander

   on Mar 10, 2026
3. github-actions

   added

   opentuiThis relates to changes in v1.0, now that opencode uses opentuiThis relates to changes in v1.0, now that opencode uses opentui

   on Mar 10, 2026
4. github-actions commented on Mar 10, 2026

   

   github-actionsBot

   on Mar 10, 2026 – with GitHub Actions

   Contributor

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   This issue might be a duplicate of existing issues. Please check:

   • TUI rendering glitches: overlapping panels, misaligned content, and corrupted layout #11109: TUI rendering glitches with overlapping panels and misaligned content — very similar symptoms of UI elements rendering on top of each other
5. lazyalex616 commented on Mar 10, 2026

   

   lazyalex616

   on Mar 10, 2026

   Last edited by lazyalex616

   More actions

   I looked into the source code to understand how this could happen. Here's what I found and a step-by-step way to narrow down the root cause.

   Background: How the TUI renders

   OpenCode's TUI explicitly disables stdout interception (renderer.disableStdoutInterception() in app.tsx) and does not use an alternate screen buffer. This means anything that writes to stdout outside the TUI's render cycle will paint directly over it.

   The Header component uses flexShrink={0} (fixed position), and the message area below uses flexGrow={1}. Under normal conditions this layout is stable, but if something interferes with the render cycle (extra stdout writes, or unexpected terminal state changes), the layout can break.

   This is NOT a duplicate of #11109

   #11109 is intermittent, happens without plugins, and only during long sessions with multiple tabs. Your issue is every single time on message submit — very different pattern.

   Isolation steps to find the root cause

   Try these one at a time, restarting OpenCode between each step. Stop as soon as the overlap disappears — that step identified the culprit.

   Step 1: Rule out plugins

   Remove oh-my-opencode from your config (set plugins: [] or delete the entry), restart OpenCode, and submit a few messages.

   • Overlap gone → plugin is involved, continue to Step 1b
   • Overlap still there → skip to Step 2

   Step 1b: If removing the plugin fixed it, check which version you have (oh-my-opencode --version or look in node_modules). Make sure it's ≥ 3.9.0 — older versions had a known bug where bun install output leaked into the TUI (#15357). Reinstall with latest and test again.

   Step 2: Rule out iTerm2

   With the same config (plugins removed or not, depending on Step 1), try running OpenCode in a different terminal:

   • macOS built-in Terminal.app

   • Ghostty or Kitty if you have them

   • Overlap gone in other terminal → iTerm2-specific rendering issue. Check iTerm2 settings: Preferences → Profiles → Terminal → "Terminal Emulation" section. Try toggling "Unicode version" and "Ambiguous characters" settings.

   • Overlap still there → not terminal-specific, continue to Step 3

   Step 3: Check OpenCode version

   You listed 1.2.* — can you share the exact version? (opencode --version). OpenTUI's layout engine had several fixes in recent releases. If you're not on the latest, try upgrading.

   Step 4: Collect debug info

   If none of the above resolves it, this info would help the maintainers:

   # Terminal size
   tput cols; tput lines
   
   # OpenCode exact version
   opencode --version
   
   # iTerm2 version
   # (iTerm2 menu → About)
   
   # oh-my-opencode version (if using)
   cat node_modules/oh-my-opencode/package.json | grep version
   
   # Does resizing the terminal window fix/change the overlap?
   # (Try making it wider/narrower while the overlap is visible)

   Also: does the overlap happen immediately on the first message of a fresh session, or only after a few exchanges?

   👍React with 👍1Reacted by max.hu
6. fenggeHu commented on Mar 10, 2026

   

   fenggeHu

   on Mar 10, 2026

   Author

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   I looked into the source code to understand how this could happen. Here's what I found and a step-by-step way to narrow down the root cause.

   Background: How the TUI renders

   OpenCode's TUI explicitly disables stdout interception (renderer.disableStdoutInterception() in app.tsx) and does not use an alternate screen buffer. This means anything that writes to stdout outside the TUI's render cycle will paint directly over it.

   The Header component uses flexShrink={0} (fixed position), and the message area below uses flexGrow={1}. Under normal conditions this layout is stable, but if something interferes with the render cycle (extra stdout writes, or unexpected terminal state changes), the layout can break.

   This is NOT a duplicate of #11109

   #11109 is intermittent, happens without plugins, and only during long sessions with multiple tabs. Your issue is every single time on message submit — very different pattern.

   Isolation steps to find the root cause

   Try these one at a time, restarting OpenCode between each step. Stop as soon as the overlap disappears — that step identified the culprit.

   Step 1: Rule out plugins

   Remove oh-my-opencode from your config (set plugins: [] or delete the entry), restart OpenCode, and submit a few messages.

   • Overlap gone → plugin is involved, continue to Step 1b
   • Overlap still there → skip to Step 2

   Step 1b: If removing the plugin fixed it, check which version you have (oh-my-opencode --version or look in node_modules). Make sure it's ≥ 3.9.0 — older versions had a known bug where bun install output leaked into the TUI (#15357). Reinstall with latest and test again.

   It's right here!

   From opencode/log:

   26-03-10T07:41:37 +8ms service=plugin path=oh-my-opencode loading plugin
   WARN 2026-03-10T07:41:38 +1075ms service=bun pkg=oh-my-opencode cachedVersion=3.8.5 Failed to resolve latest version, using cached
   INFO 202
7. fenggeHu

   closed this as completedon Mar 10, 2026