You can try something like this

#+BEGIN_SRC emacs-lisp
(setq bibtex-completion-format-citation-functions
      '((org-mode      . (lambda (keys) (org-ref-insert-cite-keys keys) ""))
        (latex-mode    . bibtex-completion-format-citation-cite)
        (markdown-mode . bibtex-completion-format-citation-pandoc-citeproc)
        (default       . bibtex-completion-format-citation-default)))
#+END_SRC

it seems like ivy-bibtex at least expects some kind of string to be
returned, but org-ref-insert-cite-keys does the insertion for you.

On Sun, Feb 26, 2023 at 11:19 AM Sven Bretfeld <sven.bretfeld@ntnu.no>
wrote:

> Hi everybody
>
> Is it at all possible to produce a correct org-ref citation format
> from ivy-bibtex (or helm-bibtex, I tried both)? What I mean by
> "correct" is the format: [[cite:&citekey]].
>
> The problem seems to come down to the question what has to be inserted
> in the 2nd line here:
>
> (setq bibtex-completion-format-citation-functions
>       '((org-mode      . ??????)
>         (latex-mode    . bibtex-completion-format-citation-cite)
>         (markdown-mode . bibtex-completion-format-citation-pandoc-citeproc)
>         (default       . bibtex-completion-format-citation-default)))
>
> (A) Not setting the variable at all, defaults to producing an ebib
> link which is of no use to me at all.
>
> (B) Putting org-ref-helm-bibtex-insert-citation here (as found on
> reddit) does not work, since the function does not seem to exist
> anymore.
>
> (C) Putting org-ref-insert-cite-link here is obviously wrong. Choosing
> that from the list of ivy-bibtex-actions, just calls the function
> interactively, you have to search for the bib-entry again and the
> resulting link looks like: [[cite:&citekey]]^&. The terminating '^&'
> obviously makes subsequent LaTeX-exports fall.
>
> (D) Putting "bibtex-completion-format-citation-org-cite" here,
> produces standard org-links: [cite:@citekey]. These are not correctly
> exported to a tex file when the org-ref package is loaded.
>
> The only working solution I have found is to use org-ref's own cite
> function org-ref-insert-cite-link. I know that ivy-bibtex can be set
> as backend (require 'org-ref-ivy). But in this way ivy-bibtex's other
> actions (like opening an associated PDF or note file) are lost.
>
> It would be nice to be able to use a SINGLE key-binding to select a
> bib-entry and then decide what to do with it (insert org reference,
> insert tex reference, open pdf, etc.). This was possible earlier (I
> did that for years with older versions of org-ref-helm) but is
> apparently no longer possible now.
>
> Many thanks for help and suggestions,
>
> Sven
>
>