Required Field Indicator
Make it obvious which fields must be filled in and which may be left alone.
What it adds
A consistent marking of required and optional fields across every form in the app.
What your agent is told to do
5
What your agent is told to do
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1
Count the required and optional fields across the app's forms and pick the convention that marks the minority — if most fields are required, mark the optional ones instead.
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2
Apply the chosen convention to every form without exception, and state the convention once at the top of each form so the marker means something to a first-time reader.
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3
Expose the requirement to assistive technology as well as visually, so the control itself reports that it is required rather than relying on a symbol beside the label.
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4
Recompute the marking when requirements change at runtime — a field that becomes mandatory once a plan or a country is selected must gain its marker and its announcement immediately.
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5
Do not mark a read-only, disabled, or system-populated field as required. It tells the user to act on something they cannot touch, and it makes the marker untrustworthy everywhere else.
Edge cases it handles
7
Edge cases it handles
7- A bare asterisk carries no meaning to a screen reader and is often skipped entirely; the requirement must be on the control, not only in the label's punctuation.
- The form-level legend explaining the convention must match what the fields actually do, and a form that mixes required-marking with optional-marking teaches the user nothing.
- Requirements that change mid-form must update the marker, the accessible state, and the validation rule together — a field that validates as required but shows no marker looks like a bug.
- A field that is required by the server but not marked in the interface produces an error the user could not have anticipated; the marking must reflect the actual validation.
- A field required only in one branch of a conditional flow must lose its marker when that branch is not active, rather than staying marked and blocking submission invisibly.
- The marker must not be conveyed by colour alone, and it must survive at compact density without colliding with a long label.
- How the marker is placed in the label and linked to the control is owned by Form Field Shell; this entry owns which fields are marked and what the convention is.
Definition of done
8
Definition of done
8- One convention — marking required or marking optional — is used across every form.
- Each form states its convention once, visibly.
- Requirements are exposed programmatically on the control, not only as a visual symbol.
- Marking matches the validation actually enforced on submission.
- Requirements that change at runtime update the marker and the accessible state together.
- Read-only, disabled, and system-populated fields are never marked required.
- 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
Input Group Component
Input Group Component
Join prefixes, suffixes, and buttons to an input so they read as one control.
What it does
A composite control binding an input to adjoining affixes and buttons within a single visual frame.
How it works
- 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.
- 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.
- 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.
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/input-group-component
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.