linkput is an unofficial, opinionated, and (I think) very useful companion for the Linkhut bookmarking service, supporting both desktop and android versions of Firefox.

Before it can be used you must save your API key in the extensions preferences. The extension maintains a full local cache of your bookmarks, enabling lightning-fast search, offline access, and powerful management tools that aren't possible with the standard web interface. Core Features

Quick Saving: Save the current page to your Linkhut account by simply clicking on the toolbar icon or by using the Ctrl+Shift+L shortcut (to change the hotkey, go to about:addons, click the gear icon, and select "Manage Extension Shortcuts", you'll find the option there).
Pre-Save Editing: The popup allows you to edit the bookmark's title, add tags, write notes, and set 'unread' or 'private' status before saving.
Edit Existing Bookmarks: Clicking the toolbar icon on a page you've already saved will open the popup with the existing data pre-filled, allowing you to quickly edit it. All your bookmarks can also be edited from the cache viewer page (see below in Advanced Features).
"Via" Linking: Easily reference another bookmark from your collection in the notes field, perfect for tracking sources or related links.
Smart Icon (desktop only): The toolbar icon changes according to a traffic light system reflecting the status of the current page in your collection.
RED — not saved
YELLOW — saved but marked 'unread'
GREEN — saved and read

Advanced features Accessed via the "Extension Dashboard" link in the popup, the dashboard provides a full-featured interface to browse and manage your entire bookmark collection locally. Bookmarks view

All bookmarks are displayed in a responsive, easy-to-scan list, perfect for large collections. Have 10,000 bookmarks? Cool. The list still scrolls like butter thanks to virtual scrolling.
Structured Search: Go beyond simple text search with powerful query prefixes. You can combine multiple queries for incredibly specific filtering.
tag:javascript Finds bookmarks tagged with "javascript"
site:github.com Finds bookmarks from the github.com domain.
title:"my project" Finds bookmarks with "my project" in the title
notes:todo Finds bookmarks with "todo" in the notes field.
site:developer.mozilla.org tag:css "flexbox guide" Finds bookmarks from MDN that are tagged css and contain "flexbox guide" in any field.
Edit or delete any bookmark directly from the list without leaving the page.
See all your tags in one place. Click any tag to instantly filter your bookmarks.

Duplicate Finder:

It's easy to end up with page anchors or tracking parameters in your saved URLs. linkput will will detect duplicates that differ only by protocal (http/https), by presence or lack of a 'www' subdomain, by page anchor, and by tracking parameter. detecting duplicates,
Merge them with a click. You choose the canonical link, and linkput automatically combines the tags and notes so you lose nothing, then deletes the duplicate from your collection.

URL & Title Modification Rules (Regex) Automatically clean up URLs and titles before they are saved. This is perfect for removing tracking parameters, normalizing URLs, or tidying up messy page titles.

Rules are based on JavaScript regular expressions (Regex). If a URL's domain matches a rule's "Domain Pattern", the "URL Regex" and "Title Regex" will be applied.
Example Rule: To remove all UTM tracking parameters from any URL:
Domain Pattern: .* (matches all domains)
URL Regex: (\?|&)utm_.*?(&|$)
URL Replace: ? (or leave blank if it might be the only parameter)

Bulk Tag Operations Easily rename a tag across all of your bookmarks (e.g., rename all js tags to javascript). Setup After installing, you must configure the extension with your Linkhut API token:

Click the extension icon in your toolbar and select "Extension Options" from the popup.
Go to your Linkhut API settings page: https://ln.ht/_/oauth.
Generate a new oauth token and copy it.
Paste the token into the "Linkhut API Token" field in the extension's options and click "Save API Settings".
Click the "Refresh Now" button
You're all set :)

Privacy I don't want your data. Any of it. This extension does not send any data to the developer (myself) or any third party and never will. The extension manifest itself prevents the extension from connecting to any remote domain other then api.ln.ht.

The extension only communicates with the api.ln.ht domain to perform actions on your behalf.
Your API token and modification rules are stored using storage.sync, which may be synchronized across your Firefox instances if you have an account (unfortunately this only works for desktop as firefox sync doesn't sync extension options between desktop and android).
Your bookmark cache is stored using storage.local, which is kept only on your local machine.