How to mark attachments as used in backend api?

[hulmgulm]

Hi,
I have a script which uses the backend api to get a note, get that notes attachments and add an img tag for each image attachment to the note. This works fine, but after adding the link, the attachment is still marked as unused and will be deleted in 29 days.
How can I tell Trilium, that this attachment is now in use?

  const  levelNote = api.searchForNote('#levelId=4711');
  let html = '';
  const attachments = levelNote.getAttachments();
  attachments?.forEach(attachment => {
      if (attachment.role === 'image') {
          html += `<img src="api/attachments/${attachment.attachmentId}/image/${attachment.title}">`;
      }
  });
  levelNote.setContent(html);

[dosubot[bot]]

Your code looks correct! Trilium automatically detects attachment usage by scanning the note content for the pattern api/attachments/{attachmentId}/image/{filename} after you call setContent(). The checkImageAttachments function handles this automatically.

There's no explicit "markAsUsed" API method — the detection happens through content parsing when note content is updated.

A few things to check:

1. Verify the URL format matches exactly: The regex looks for src="[^"]*api/attachments/{id}/image — make sure there's no leading slash (your code looks fine)
2. The detection runs asynchronously via asyncPostProcessContent, so it may take a moment after setContent() for the status to update
3. Check if the attachments belong to the same note — if you're referencing attachments from a different note, Trilium will automatically copy them to the current note

If the attachments are still showing as unused, could you confirm the exact HTML being written and whether the attachments originally belong to levelNote?

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[hulmgulm]

The URLs are correct, as you've already seen in the code and the attachments are part of the note the code updates.
Is there any way to check what asyncPostProcessContent does?
Or do you have other ideas?

[dosubot[bot]]

Found the issue! BNote.setContent() does NOT trigger asyncPostProcessContent() — it only saves the content and emits an event. The attachment detection logic never runs.

Looking at how the ETAPI routes handle this, they explicitly call asyncPostProcessContent() after setContent(). Backend scripts need to do the same.

Try adding this after your setContent() call:

const noteService = require('../services/notes');
levelNote.setContent(html);
await noteService.asyncPostProcessContent(levelNote, html);

The asyncPostProcessContent() function triggers the call chain that scans for attachment references and clears the utcDateScheduledForErasureSince field for any attachments found in the content.

To reply, just mention @dosu.

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[hulmgulm]

Thank you, but I cannot require from a Backend JavaScript Note.

[dosubot[bot]]

Good point! You can work around this by directly modifying the attachment's utcDateScheduledForErasureSince property — this is exactly what the internal checkImageAttachments function does.

Update your script to:

const levelNote = api.searchForNote('#levelId=4711');
let html = '';
const attachments = levelNote.getAttachments();

attachments?.forEach(attachment => {
    if (attachment.role === 'image') {
        html += `<img src="api/attachments/${attachment.attachmentId}/image/${attachment.title}">`;
        
        // Mark attachment as used
        attachment.utcDateScheduledForErasureSince = null;
        attachment.save();
    }
});

levelNote.setContent(html);

Setting utcDateScheduledForErasureSince to null and calling save() clears the deletion schedule, marking the attachment as used.

To reply, just mention @dosu.

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[hulmgulm]

This works.