Snap To Bottom

Typing snaps the opencode transcript back to the bottom, the way a terminal treats scrollback.

opencode pins the transcript while output streams and after you submit, but once you scroll up it stays up until you scroll all the way back down. In Claude Code the transcript is the terminal's scrollback, so its behaviour is really the terminal emulator's: any keystroke jumps to the bottom, new output does not, and the scrollback keys never reach the app. This ports that rule.

Install

// ~/.config/opencode/tui.json
{ "plugin": ["opencode-snap-to-bottom"] }

Or from a checkout: { "plugin": ["./path/to/opencode-snap-to-bottom"] }. Restart opencode afterwards.

Behaviour

Snapping fires on any keystroke except opencode's own scroll and message-navigation commands (session.page.*, line.*, half.page.*, first, last, message.*, messages_last_user). It identifies those by recording the dispatched command name from the keymap dispatch event, so it follows your keybinds — rebind them and it still works.

It does nothing while a dialog is open or in modal/question mode, so the command palette's filter is never hijacked. Landing exactly on scrollHeight - viewport.height re-arms opencode's own sticky scroll, so follow-the-output resumes.

Options

{ "plugin": [["opencode-snap-to-bottom", { "trigger": "typing" }]] }

Option	Default	Meaning
trigger	"any-key"	Every keystroke except scroll commands (terminal-faithful). "typing" restricts it to characters actually landing in the prompt.
paste	true	Also snap when pasting into the prompt.

Verified against opencode 1.18.27

Case	Result
Scroll up, type one character	Snaps to bottom
PageUp / PageDown	Still scroll freely
Home (jump to first message)	Stays at top
Esc, ↑ history recall	Snap
Palette open, typing a filter	Transcript stays put
Typing while already at bottom	No-op

Finding the transcript: it is the only scrollbox in the TUI with stickyScroll && stickyStart === "bottom", which makes that a stable discriminator — the sidebar, dialogs, autocomplete and diff viewer all have non-sticky scrollboxes.