Since I want to interconnect Org Roam notes with my Anki cards and Freeplane mindmaps, I need to create a customized link type like this roam://<org-roam-node-id>, which can be directly opened from other programs.

  1. Create an Elisp function for opening the Org Roam node by id:

    (defun tjh/org-roam-open-node-by-id (id)
  (interactive "sNode id:")
  (let ((node (org-roam-node-from-id id)))
    (if node (org-roam-node-visit node))))

  2. Create a Bash script open-org-roam-node-link.sh, which uses emacsclient to evaluate the elisp code to open the node:

    #!/bin/bash
emacsclient --eval "(let ((node (org-roam-node-from-id (substring \"$1\" 7 nil)))) (if node (org-roam-node-visit node) (message \"Node not found!\")))"

  3. Create a new desktop file ~/.local/share/applications/roam-url-handler.desktop:

    [Desktop Entry]
Name=Roam URL Handler
Exec=/usr/local/bin/scripts/open-org-roam-node-link.sh %u
Terminal=false
Type=Application
NoDisplay=true
MimeType=x-scheme-handler/roam;

  4. Register the above desktop file:

    xdg-mime default roam-url-handler.desktop x-scheme-handler/roam

  5. Insert roam://<org-roam-node-id> links in other programs, such as Anki:

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