Accessible Multi-Select
Let people pick many items and always know exactly what they have picked.
What it adds
A multi-select whose selection state is visible, removable, and announced — chips, counts, select-all, and a keyboard model that works.
What your agent is told to do
5
What your agent is told to do
5-
1
Render each selection as a removable chip with an accessible label naming the item, not a bare X.
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2
Define one keyboard model and stick to it: arrows move through options, Space or Enter toggles, Backspace on an empty input removes the last chip, Escape closes the list without discarding selections.
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3
Announce the selection count on every change through a polite live region, and announce removals by name.
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4
If the app already has a typeahead or suggestion component, extend it rather than building a second one. This feature is about selection state, not about searching.
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5
Do NOT let bulk removal happen without recourse. Select-all and clear-all must state how many items they affect and be undoable.
Edge cases it handles
7
Edge cases it handles
7- Selected items that fall outside the current search results must stay selected and stay visible.
- The same item must never be selectable twice, including via paste or programmatic set.
- Select-all must mean all matching the current filter, and must say so — not all options in existence.
- A large selection must collapse to a count with a way to expand, so the chip pile does not swallow the page.
- Removing a chip must move focus to a predictable neighbour, never to the body.
- Chips must wrap and remain tappable at 320px, with touch targets large enough to hit.
- A maximum selection limit must be announced before it is hit, not enforced by a silent no-op.
Definition of done
8
Definition of done
8- Every selection is visible as a labelled, removable chip.
- The whole control is operable by keyboard alone, with a documented key map.
- Selection count and individual removals are announced to screen readers.
- Selected items survive searching and filtering the option list.
- Duplicate selections are impossible.
- Select-all and clear-all state their scope and can be undone.
- The feature matches the existing design system.
- No existing functionality is broken.
Related features
Unit Converter
Unit Converter
Let people convert a value between units without leaving the page they are on.
What it does
An inline converter that takes a typed value in one unit and shows the equivalent in another, in place.
How it works
- 1 Start from the units the app actually deals in. A shipping tool needs weight and length; a recipe tool needs volume and temperature. Ship those and leave the rest out.
- 2 Convert as the user types, with the result visible beside the input rather than behind a submit button. Let either side be edited so the conversion runs in both directions.
- 3 Reuse the app's existing number parsing and display formatting rather than writing new ones. If Locale-Aware Numbers and Dates or Number Formatting Component is already present, the converter must render through it so grouping and decimal marks match the rest of the app.
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/unit-converter
Voice Dictation
Voice Dictation
Put a microphone in text fields so people can speak their input instead of typing it.
What it does
A dictation control on the app's longer text inputs that transcribes speech into the field as the user talks.
How it works
- 1 Add the control to the fields where typing is genuinely tedious: long descriptions, notes, comments, and message bodies. A microphone on a postcode field is clutter.
- 2 Show interim results in the field as they arrive, visually distinct from committed text, so the speaker can see it is working and correct course before they finish.
- 3 Reuse the app's existing Voice Transcription for the server-side path so one recognition configuration and one set of language settings serve both dictation and recorded audio.
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/voice-dictation
Code Editor Field
Code Editor Field
Edit code, JSON, and config with syntax highlighting instead of a bare textarea.
What it does
A form field backed by a real code editor: syntax highlighting, a language mode per field, and inline validation that tolerates work in progress.
How it works
- 1 Load the editor library lazily, only on views that use it, and render a usable plain textarea until it arrives. It must never block first paint.
- 2 Set the language mode per field from what the field actually holds, and validate against that mode.
- 3 Report syntax errors as you go, but never block typing or reset the content. Half-written JSON is a normal intermediate state; only submission should be gated.
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/code-editor-field
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.