opencode: can't scroll up/down, instead, just scrolls the emacs buffer

[anonimitoraf]

Hi, I'm running opencode in vterm but I can't scroll. Any workarounds for this?

2026-02-20.23-21-16.mp4

[LemonBreezes]

Same. Seems the mwheel keys are mapped to the scroll commands for Emacs rather than being sent to Vterm. I have not fixed this.

[lambdachad]

Same issue here.

[lambdachad]

This fixes it for me, although it does affect regular scrolling in vterm (which might not be a big deal?):

(with-eval-after-load 'vterm
  (define-key vterm-mode-map [wheel-up]      (lambda () (interactive) (vterm-send-key "<prior>")))
  (define-key vterm-mode-map [wheel-down]    (lambda () (interactive) (vterm-send-key "<next>")))
  (define-key vterm-mode-map [mouse-4]       (lambda () (interactive) (vterm-send-key "<prior>")))
  (define-key vterm-mode-map [mouse-5]       (lambda () (interactive) (vterm-send-key "<next>"))))

[lambdachad]

I'm using following:

(use-package vterm
  :bind (:map vterm-mode-map
         ("<wheel-up>" . (lambda () (interactive) (vterm-send-key "<prior>")))
         ("<wheel-down>" . (lambda () (interactive) (vterm-send-key "<next>")))))

This modifies the regular scrolling in vterm from scrolling the buffer to passing it on to vterm, which makes scrolling regularly in vterm switch between prompts.

[lambdachad]

After testing how I can get this working as smoothly as possible I landed on this:

(use-package vterm
  :bind (:map vterm-mode-map
       ("S-<return>" . (lambda () (interactive) (vterm-send-string "\e[13;2u")))
       ("<wheel-up>"   . (lambda (e) (interactive "e") (if (string-match-p "OpenCode\\|OC |" (buffer-name)) (vterm-send-key "<prior>") (mwheel-scroll e))))
       ("<wheel-down>" . (lambda (e) (interactive "e") (if (string-match-p "OpenCode\\|OC |" (buffer-name)) (vterm-send-key "<next>")  (mwheel-scroll e)))))
  :custom
  (vterm-buffer-name-string "vterm: %s")

This checks the buffer if OpenCode or OC is in the name, then it sends the scroll event accordingly. Initially tried checking process, but this was super slow. This requires prompt tracking to be enabled also in the terminal.

Also added shift-return so that one works too.

[anonimitoraf]

Awesome! Thanks for that @svelterust. Works for me too