Compound Component Pattern
Let related parts of a component share state while the caller keeps control of the arrangement.
What it adds
Groups of subcomponents that coordinate shared state internally while leaving structure and ordering to the call site.
What your agent is told to do
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What your agent is told to do
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Identify the components currently configured through long lists of props for their internal parts — a tabs component taking an array of labels, a dialog taking title, body, and footer as strings — and let the caller compose those parts instead.
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Keep the shared state inside the group. Selection, open state, active index, and registration of the parts are the group's responsibility, and callers should not have to wire them together to get correct behaviour.
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Support both a self-managing mode and a caller-controlled mode for the shared state, and make them mutually exclusive rather than allowing a half-controlled configuration that fights itself.
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Give each subcomponent a clear error when it renders outside its group, naming the parent it requires. A part that silently renders inert because it found no shared state is very hard to diagnose from a screenshot.
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Do not couple the parts by inspecting children, cloning them, or reaching for a particular position in the child list. That breaks the moment someone wraps a part in a conditional, a layout element, or a component of their own — which is exactly the flexibility this pattern exists to allow.
Edge cases it handles
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Edge cases it handles
7- A subcomponent rendered outside its required parent must fail with a message naming that parent rather than rendering as an inert element. Silence here produces a control that looks right and does nothing.
- Reordering or wrapping the parts must not break accessibility. The relationships that assistive technology relies on — which label belongs to which panel, which trigger controls which region — must be established through explicit association rather than through the order the parts happen to appear in.
- Shared state passed implicitly is easy to depend on by accident. Keep what the group provides deliberately small and documented, so a caller cannot end up relying on internals that change in the next release.
- Both a self-managing and a caller-controlled mode must be supported, and switching between them mid-life must be refused or handled explicitly rather than leaving two sources of truth disagreeing about which item is selected.
- Parts rendered conditionally, in a loop, or through an intermediate wrapper must still register with the group, so keyboard navigation and roving focus cover exactly the parts that are present.
- Nesting one group inside another — a menu within a menu, tabs within a panel — must resolve to the nearest enclosing group, not the outermost one.
- Duplicated or missing required parts, such as two panels claiming the same identifier or a trigger with no matching panel, need a development-time warning.
Definition of done
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Definition of done
9- Related components are composed at the call site rather than configured through arrays or slot-shaped prop lists.
- Shared state is owned by the group, and callers get correct behaviour without wiring it themselves.
- A subcomponent used outside its parent raises an error naming the required parent.
- Self-managing and caller-controlled modes are both supported and cannot be mixed.
- Wrapping, reordering, or conditionally rendering the parts leaves accessibility relationships intact.
- The group's implementation never inspects, clones, or indexes into its children.
- Nested groups resolve to the nearest enclosing parent.
- The feature matches the existing design system.
- No existing functionality is broken.
Related features
Avatar Group
Avatar Group
Show who is involved in a compact space without a pile of broken images.
What it does
A stacked set of member avatars with deterministic ordering, an overflow count, and access to the full list.
How it works
- 1 Find the places that show several people at once — assignees, collaborators, workspace members, comment participants — and render them through one grouped component.
- 2 Order the stack deterministically by a stable rule such as role then name, so the same group renders in the same order on every load and every device.
- 3 Cap the number shown and collapse the remainder into a single count that is announced meaningfully, not as a bare number sitting after a row of pictures.
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/avatar-group
Stepper Component
Stepper Component
Show people where they are in a multi-step flow and what is still ahead of them.
What it does
A single stepper used by every staged flow in the app, showing step order, completion, and errors.
How it works
- 1 Find every staged flow the app already has — onboarding, checkout, import wizards, multi-page settings — and render them all through one stepper rather than the three variants that have grown up separately.
- 2 Keep completion and navigation as two distinct concepts. A step can be complete without being current, and a step the user is allowed to jump back to is not the same as a step they have finished.
- 3 Model optional and skippable steps explicitly, and show a skipped step as skipped rather than as complete or as untouched. A user who skipped payment details needs to see that it is still outstanding.
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/stepper-component
Dropdown Menu Primitive
Dropdown Menu Primitive
Give every action menu in the app the same keyboard, pointer, and dismissal behaviour.
What it does
A reusable menu primitive covering triggering, item navigation, selection, disabled items, and closing.
How it works
- 1 Find every action menu in the app — row overflow menus, account menus, bulk-action menus, toolbar menus — and rebuild them on one primitive so they stop behaving differently from each other.
- 2 Implement the full keyboard model: arrows move between items, Home and End jump to the ends, typing letters jumps to the matching item, Enter and Space activate, and Escape closes and returns focus to the trigger.
- 3 Close on outside pointer press, on Escape, and on the trigger being pressed again, and always return focus to the trigger so the user is not dropped at the top of the document.
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/dropdown-menu-primitive
How it works
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1
Copy the link
Grab the Markdown instruction URL for this feature.
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Give it to your AI
Paste it into Claude Code, Cursor, v0, Lovable — whatever you build with.
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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.