Slot-Based Composition
Let components take content in named positions instead of accumulating a prop per element.
What it adds
Named content positions on layout-shaped components, with defaults, validation, and an accessible source order.
What your agent is told to do
5
What your agent is told to do
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Find the components that have grown a prop for every possible piece of content — icon, title, subtitle, badge, action, footer — and replace that accumulation with a small set of named positions.
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Name each position for its role in the layout rather than for what is typically put in it, so a position remains truthful when a caller puts something unexpected there.
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Give each position a sensible default or a defined empty behaviour, so an omitted position collapses cleanly instead of leaving a gap, a stray separator, or a border around nothing.
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Keep the source order of the rendered output meaningful even where visual order differs, so keyboard and screen reader users encounter the content in a sequence that makes sense.
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Do not implement positions by matching on child type, position in the child list, or a class name applied by the caller. Those break as soon as content is wrapped or conditionally rendered, and they give a caller no way to find out what went wrong.
Edge cases it handles
7
Edge cases it handles
7- Required and mutually exclusive positions must be validated. A component with no content in its required position, or with two positions filled that were never meant to appear together, should say so at development time rather than rendering something misaligned.
- Visual order and source order can diverge once positions are laid out with a grid or reordered for a breakpoint, and when they do the keyboard tab sequence stops matching what is on screen. Keep the accessible order deliberate rather than letting the layout decide it.
- Every position needs a defined behaviour when it is empty. Reserving space for an absent icon, or drawing a separator above a footer nobody supplied, is the usual result of leaving it unspecified.
- Selecting content by child type or list position is brittle: wrapping one item in a conditional, a fragment, or a caller's own component silently drops it into the wrong place or out of the render entirely. Positions must be addressed by name.
- Content placed in a position must not be able to break the component's own layout — an over-long title, a tall image, a translated label at three times the English length — so each position needs its own constraints for wrapping, truncation, and maximum size.
- Nesting a component inside one of its own positions must resolve unambiguously, so an inner card's footer is not styled by the outer card's rules.
- The set of positions is part of the component's contract, so removing or renaming one is a breaking change and needs treating as such.
Definition of done
9
Definition of done
9- Layout-shaped components accept content by named position rather than through a prop per element.
- Positions are addressed by name, with no matching on child type, index, or class name.
- Missing required positions and mutually exclusive combinations raise development-time errors.
- An omitted position collapses cleanly, with no reserved space, stray separator, or empty border.
- Source order remains meaningful for keyboard and screen reader users at every breakpoint.
- Over-long or over-tall content in a position is constrained rather than breaking the component's layout.
- The prop-per-element accumulation on the affected components has been removed.
- The feature matches the existing design system.
- No existing functionality is broken.
Related features
Screen Reader Only Utility
Screen Reader Only Utility
One tested way to add text for assistive technology without it appearing on screen.
What it does
A single visually hidden utility used for labels, instructions, and context that assistive technology needs and sighted users do not.
How it works
- 1 Find every place the app currently hides text from sight — off-screen positioning, zero dimensions, transparent colour, tiny font sizes, aria-label strings duplicating nearby copy — and consolidate them onto one utility.
- 2 Build it by clipping the element to nothing while keeping it rendered and in the accessibility tree: it must occupy no visual space and contribute nothing to layout, yet still be read in document order.
- 3 Provide a second variant that becomes visible when it receives focus, and use it for skip links and any other hidden content that is itself focusable.
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/screen-reader-only-utility
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
Progress Indicator System
Progress Indicator System
Tell people how far along the work is, in the same way every time.
What it does
A consistent set of bars, rings, step trackers, and accompanying text for work that takes measurable time.
How it works
- 1 Identify every operation in the app that takes long enough to need feedback — uploads, imports, exports, batch actions, multi-step flows — and decide for each whether its progress is genuinely measurable.
- 2 Use a determinate form only when a real proportion is known. Where the total is unknown, use an indeterminate form and say what is happening in words rather than inventing a percentage.
- 3 Pair every indicator with text that names the operation and its current position, so the information survives for someone who cannot see the graphic.
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/progress-indicator-system
How it works
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1
Copy the link
Grab the Markdown instruction URL for this feature.
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2
Give it to your AI
Paste it into Claude Code, Cursor, v0, Lovable — whatever you build with.
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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.