Mouse selection is very unreliable and drives me nuts (vscode terminal)

[jdanbrown]

Description

I'm not sure exactly when this started, but it feels like it used to work better a month or two ago. When I click and drag to select text in the opencode cli output, most of the time it fails to register which results in no drag selection. So I have to do it again, and again, and again. Drives me totally bananas!

This bug happens in vscode terminal (where I like to use terminals), and when I test in iterm2 mouse selection works normally (I tried clicking a bunch back and forth between two splits in iterm2 and I couldn't get the bug to happen even once). Here's a screen recording in vscode terminal showing the bug:

Screen.Recording.2026-03-02.at.1.58.13.PM.mov

TUI config:

$ cat ~/.config/opencode/tui.jsonc
{
  "$schema": "https://opencode.ai/tui.json",
  "scroll_acceleration": {
    "enabled": true,
  },
  "diff_style": "stacked",
  "theme": "jdanbrown",
  "keybinds": {
    "leader": "ctrl+o",
    "app_exit": "ctrl+d,<leader>q",
    "session_timeline": "<leader>t",
    "session_child_cycle": "ctrl+alt+j",
    "session_child_cycle_reverse": "ctrl+alt+k",
    "messages_line_up": "ctrl+alt+y",
    "messages_line_down": "ctrl+alt+e",
    "messages_half_page_up": "ctrl+alt+u",
    "messages_half_page_down": "ctrl+alt+d",
    "messages_first": "ctrl+g",
    "messages_last": "ctrl+alt+g",
    "messages_next": "ctrl+alt+e",
    "messages_previous": "ctrl+alt+y",
    "model_list": "<leader>m,ctrl+m",
    "command_list": "ctrl+/,ctrl+_",
    "input_newline": "alt+enter,shift+enter,shift+return",
    "history_previous": "up,ctrl+p",
    "history_next": "down,ctrl+n",
  },
}

Plugins

none

OpenCode version

1.2.15

Steps to reproduce

No response

Screenshot and/or share link

No response

Operating System

macOS 26.2

Terminal

vscode terminal

[github-actions]

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

• Cannot select text in chat messages - mouse capture stuck in prompt field ( VSCode terminal) #15212: Similar mouse selection issues in VS Code integrated terminal (same version 1.2.15, mouse capture/selection not working in VSCode terminal)

If your issue is distinct from the above, please add a comment explaining how it differs so maintainers can keep both open.

[kommander]

I see that happen as well in Ghostty, so it might not be terminal specific and I am sure it was better at some point. I tried to reproduce the issue with tests, but didn't succeed. I need to track this down.

[simonklee]

Independent of terminal, it also matters where you start the selection. I'm not saying this is the only issue - but it's one issue.

select.mp4

[jdanbrown]

@kommander I narrowed down my repro: It doesn't happen in opencode 1.1.59 (Feb 11) but does happen in opencode 1.1.60 (Feb 12). That implicates one of the changes in opentui 0.1.77 → 0.1.79:

• https://github.com/anomalyco/opencode/releases/tag/v1.1.60
• v1.1.59...v1.1.60
• anomalyco/opentui@v0.1.77...v0.1.79

Here's the opus-4.6 chat that searched through the opentui commits to find this:

• https://opncd.ai/share/ognsrDAA

[jdanbrown]

Fwiw, in my opus-4.6 chat above it claims "VSCode terminal batches multiple mouse escape sequences into a single stdin read", in case that's a helpful lead on why this happens in vscode terminal and ghostty but not iterm2.

• https://opncd.ai/share/ognsrDAA

[kommander]

I've identified the exact commit in opentui: anomalyco/opentui@f91df10#diff-b67baa356adfb0988914fac554870cbf24924353189eb32933b549b9da71f478

Will have a closer look and get it fixed. Then selection should actually work just properly in vscode, as far as I could test at least.

[simonklee]

I've identified the exact commit in opentui: anomalyco/opentui@f91df10#diff-b67baa356adfb0988914fac554870cbf24924353189eb32933b549b9da71f478

Will have a closer look and get it fixed. Then selection should actually work just properly in vscode, as far as I could test at least.

I think its because a chunk like \x1b[I\x1b[<0;10;5M (focus-in + mouse down) results in zero parsed mouse events right now with broken up input parsing