Split View
Let users compare or edit two records side by side without opening another tab.
What it adds
Two independent panes, each holding its own record, its own URL, and its own loading and error state.
What your agent is told to do
5
What your agent is told to do
5-
1
Represent both panes in the URL so a split view can be linked, bookmarked, and restored. One pane's record must not be inferable from the other's.
-
2
Give each pane its own fetch, its own loading state, and its own error state. A failure in one pane must leave the other usable.
-
3
Scope actions to the pane they were triggered in. Saving, deleting, or navigating in one pane must never silently swap the other pane's record.
-
4
Below the responsive breakpoint, show one pane at a time with an explicit control to switch, and keep the inactive pane's state rather than discarding it.
-
5
Drag handles, minimum and maximum widths, keyboard resizing, and size persistence are owned by Resizable Panels; extend that rather than building a second resize implementation.
Edge cases it handles
6
Edge cases it handles
6- Opening the same record in both panes must either be prevented or kept genuinely in sync — two stale copies of one record is the worst outcome.
- Deleting the record in one pane must leave that pane in a clear removed state, not a blank frame or a redirect that closes the split.
- A restored split view must handle a record that is now deleted or no longer permitted, showing that pane's own error rather than failing the whole view.
- Unsaved edits in a pane must survive the other pane navigating, and must be flagged before the split is closed.
- Keyboard focus must move between panes deliberately, and each pane needs a landmark or label so screen reader users know which is which.
- A global search or command action must have a defined target pane — the focused one — rather than picking one at random.
Definition of done
8
Definition of done
8- Both panes are encoded in the URL and the view restores from it.
- Each pane loads, errors, and empties independently.
- An action in one pane never changes the other pane's record.
- Narrow screens present a single pane with an explicit switch that preserves both panes' state.
- Restoring a split view with a deleted or forbidden record degrades that pane only.
- Resize behaviour is delegated to Resizable Panels, not reimplemented.
- The feature matches the existing design system.
- No existing functionality is broken.
Related features
Beautiful Empty States
Beautiful Empty States
Replace blank screens with useful, contextual empty states.
What it does
Every list, table, and dashboard in your app has a "nothing here yet" state. Most
apps ship a blank rectangle — and it is often the very first thing a new user sees.
An empty state should say what belongs here, why it is empty, and what to do next.
How it works
- 1 Inventory the empty cases first. List every collection view in the app and
- 2 Distinguish the three kinds of empty. They are not the same, and must not
- 3 Build one reusable empty-state component from the existing design system,
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/beautiful-empty-states
Opening Hours Display
Opening Hours Display
Say whether you are open right now and when you next open.
What it does
A live open or closed state alongside the weekly hours, with holiday closures folded in.
How it works
- 1 Lead with the current state in plain words and follow it with the next transition: open until a time, or closed until a day and time. The weekly table is supporting detail, not the headline.
- 2 Store hours as intervals against the business's own zone, and keep holiday and one-off closures as overrides that win over the regular week rather than as edits to it.
- 3 Compute the state on the server for the first render so the page does not briefly claim the wrong thing, then let the page update itself as the clock crosses a boundary without a reload.
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/opening-hours-display
Dark Mode
Dark Mode
Add a dark theme that respects the system preference and the user's choice.
What it does
A complete dark theme, defaulting to the operating system preference and overridable by the user.
How it works
- 1 Audit every colour in the app first and report where they are defined. If colours are hardcoded throughout, extract them into tokens before anything else — that refactor is the bulk of this work.
- 2 Define a dark palette against those tokens. Do not simply invert the light theme.
- 3 Default to the system preference via prefers-color-scheme, and let the user override it.
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/dark-mode
How it works
-
1
Copy the link
Grab the Markdown instruction URL for this feature.
-
2
Give it to your AI
Paste it into Claude Code, Cursor, v0, Lovable — whatever you build with.
-
3
It inspects, then implements
Your agent reads your existing app first, then adds the feature to fit it.
Works with your stack
These instructions are written to adapt. They tell the agent to detect your framework, match your existing design system, and reuse what you already have — rather than assuming a particular stack.
Need it tighter than that? Customize the feature and tell it exactly what you're running.