Prompt input keybind analysis: hybrid emacs/monaco cheatsheet + patch inventory #32721

Context

OpenCode TUI defaults to emacs-style input keybindings. Our patch-selectall creates a hybrid emacs/monaco model inspired by VS Code Monaco editor chat input. This ticket documents the current state as a cheatsheet for future iteration.

Upstream Emacs Defaults (unpatched)

Our Hybrid (patch-selectall + tui.json)

Changes made by patch-selectall

Changes made by tui.json (runtime overrides)

Changes made by patch-background-keybind (NOW DISABLED — tui.json handles it)

This patch was disabled in favor of tui.json runtime overrides:

• session_background: ctrl+b → ctrl+o (same as tui.json)
• input_move_left: left,ctrl+b → left (same as tui.json)

Current Hybrid Cheatsheet

Prompt Input — Movement

Prompt Input — Selection

Prompt Input — Editing

Prompt Input — Scrolling

Global — Messages

Global — Session

Zellij Passthrough Notes

ctrl+b is zellij's tmux prefix key. When inside zellij:

• ctrl+b is captured by zellij → never reaches opencode
• Only ctrl+b passthrough sequences work (e.g., ctrl+b then z for zoom)
• This is why input_move_left and session_background needed remapping

When NOT inside zellij (plain alacritty):

• ctrl+b would work for both, but tui.json overrides make it consistent
• No zellij passthrough needed

Inconsistencies & Future Iteration Ideas

1. ctrl+e still emacs, but ctrl+a is monaco — asymmetric. Consider remapping ctrl+e → End only, or keep both for muscle memory.
2. ctrl+u deletes to line start (emacs), not universal-arg — fine for terminal, surprising for emacs users.
3. ctrl+v paste (not emacs page-down) — already overridden upstream, matches terminal conventions.
4. ctrl+a = select-all + auto-copy — unusual. Monaco selects but doesn't copy. Consider making copy optional.
5. PageUp/PageDown local to prompt — good for long prompts, but users might expect message scrolling. Consider shift+PageUp for message scroll.
6. No ctrl+z undo — upstream has no prompt undo. Future patch candidate.
7. No ctrl+y redo — same, future candidate.
8. ctrl+k kill-line is emacs — useful, keep. But no visual feedback like monaco.
9. Home/End freed from global nav — good, but ctrl+g / ctrl+alt+g are less discoverable. Consider <leader>g / <leader>G.

Patch Dependency Graph

patch-selectall (always-on)
├── SA1: input_line_home ctrl+a → home
├── SA1b: messages_first/last freed from home/end
├── SA1c: messages_page_up/down freed from pageup/pagedown
├── SA2: select-all action (no-op on v1.17.4+)
├── SA3: input_select_all ctrl+a, input_copy_selection
├── SA4: prompt handlers (select-all, copy, home/end, pgup/pgdn)
├── SA5: ESC clears selection
└── SA6: dynamic interrupt label

patch-background-keybind (DISABLED — tui.json handles it)
├── session_background: ctrl+b → ctrl+o
└── input_move_left: left,ctrl+b → left

tui.json (runtime, no patch needed)
├── session_background: ctrl+o
├── input_move_left: left
├── app_exit: <leader>q
└── leader: ctrl+x

Build Status

• patch-background-keybind disabled by default (INCLUDE_BACKGROUND_KEYBIND=false)
• Re-enablable with --background-keybind flag
• Current build: 1.17.7-dev-patched-380ddd193b (still has old patch)
• Next build: will skip background_keybind, tui.json handles rebinding