Input Group Component
Join prefixes, suffixes, and buttons to an input so they read as one control.
What it adds
A composite control binding an input to adjoining affixes and buttons within a single visual frame.
What your agent is told to do
5
What your agent is told to do
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1
Find the places the app already fakes this — a currency symbol floating beside a number field, a copy button jammed next to a token, a domain suffix drawn as separate text — and rebuild them as one group.
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2
Draw the focus treatment around the whole group when any child inside it holds focus, so the composite reads as one control rather than a box beside a button.
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3
Give the group one accessible name from the field's label and describe affixes separately; a currency symbol or a unit must be exposed as description, not as a second label.
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Manage borders and corner radii from the group so the first and last visible children round correctly no matter which affixes are present, including when one is conditionally hidden.
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5
Do not let a button inside the group become the form's default submit by accident. Declare each embedded button's behaviour explicitly, because a reveal or copy control that submits the form on Enter is a data-loss bug.
Edge cases it handles
7
Edge cases it handles
7- Focus lives on exactly one child at a time, but the invalid, disabled, and focused treatments belong to the frame — a ring drawn only around the inner input looks like a rendering fault.
- The affix must not repeat the label; a field labelled Amount in USD with a dollar prefix announces the currency twice to a screen reader.
- A group containing more than one control needs per-child validity — a disabled or invalid button inside the group must not make the text input unusable, and vice versa.
- Radii and borders must be recomputed when an affix appears or disappears at runtime, or the group will render with a square corner in the middle of a rounded frame.
- Long affix content and long input values must not push the group past its container; the input should shrink and the affixes hold their intrinsic width.
- Every embedded icon-only button needs an accessible name and a hit area meeting the minimum touch target, even when the group is rendered at compact density.
- The label, description, and error text around the group are owned by Form Field Shell — this component owns the inside of the frame only.
Definition of done
8
Definition of done
8- Grouped affixes, inputs, and buttons render inside a single continuous frame.
- Focus on any child produces one focus treatment on the whole group.
- The group carries one accessible name, with affixes exposed as description.
- Corner radii and borders remain correct when affixes are added or removed at runtime.
- Embedded buttons have explicit behaviour and never submit the form unintentionally.
- Icon-only buttons in the group have accessible names and adequate touch targets.
- 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
Field State Matrix
Field State Matrix
Decide once how every field looks and behaves in every state, before screens improvise.
What it does
A defined and documented set of visual and behavioural states covering every input type in the app.
How it works
- 1 Enumerate the app's input types and cross them against every state they can enter: empty, filled, focused, hovered, invalid, valid, disabled, read-only, loading, and browser-autofilled.
- 2 Define disabled and read-only as genuinely different states — a read-only field shows a real value the user may select and copy, a disabled field is inert and excluded from submission.
- 3 Define the loading state so the field is visibly busy and not editable, and say what happens to a keystroke that arrives mid-load rather than letting it be silently swallowed.
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/field-state-matrix
Form Section Pattern
Form Section Pattern
Break long forms into labelled sections people can scan instead of read.
What it does
A section pattern grouping related fields under a heading, a description, and its own actions.
How it works
- 1 Find the forms that have grown past a screenful — settings, profiles, checkout, configuration — and group their fields by the question each group answers, not by the table the columns come from.
- 2 Give each section a heading in the document's heading order and an optional one-line description, so screen reader and keyboard users can jump between sections.
- 3 Allow at most one level of nesting. A section inside a section inside a tab gives the user no orientation and pushes the fields into a narrow gutter.
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/form-section-pattern
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.