Product Variant Picker
Let shoppers pick size and colour and see price, image, and stock update as they choose.
What it adds
An option selector on the product page that resolves the chosen combination to a specific variant and updates price, imagery, and availability live.
What your agent is told to do
5
What your agent is told to do
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Model options as named groups with ordered values, and map each valid combination to a concrete variant with its own price, stock level, and identifier. The picker resolves a selection to a variant; it does not guess.
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Update price, availability, and the main image the moment a selection changes, without a page reload and without resetting the other groups the shopper has already chosen.
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Reflect the selected variant in the URL so a shared or refreshed page opens on the same choice. Read that value on load and apply it before first paint so the page does not visibly switch options.
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Drive the product's imagery through the existing Product Image Gallery rather than swapping a lone image element. When a variant has its own photos, the gallery switches to them; when it does not, it stays on the product's default set.
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Do not let an invalid combination be submitted and rejected at add-to-cart. Compute which values are still reachable given the current selection and disable the rest, with a reason on the disabled value.
Edge cases it handles
8
Edge cases it handles
8- Combinations that do not exist must be visibly unavailable in the picker, not discovered when add-to-cart fails. Recompute reachable values on every change, and when a shopper's earlier choice becomes impossible, tell them which one you cleared.
- The chosen variant belongs in the URL so it survives sharing, refresh, and the back button. Use the same identifier the server understands, and fall back to the default variant if the value is stale or unknown.
- Variants can differ in more than price. Weight, shipping class, and tax treatment all change the total, so the picker must surface a changed delivery cost rather than letting it appear as a surprise at checkout.
- A variant with no image of its own must fall back to the product's default imagery rather than rendering a broken or empty frame.
- Option groups must be keyboard navigable with arrow keys and announced as a named group with a current selection. Colour swatches need a text label as well as the colour; colour alone is not a label.
- A product with a single variant should not show a picker at all, and a product with hundreds of combinations needs the groups presented as selects rather than a grid of swatches.
- Price and stock must be re-checked server-side when the item is added. The picker's view of availability is a convenience, not authority.
- Selecting an out-of-stock but real combination should still be allowed if the app offers back-in-stock notification, so the shopper can register interest rather than hit a dead end.
Definition of done
8
Definition of done
8- Choosing options updates price, availability, and imagery without a page reload.
- Combinations that do not exist are disabled with a reason, and add-to-cart never fails on an invalid selection.
- The selected variant is encoded in the URL and restored on load before first paint.
- Variants without their own images fall back to the product default with no broken frame.
- Option groups are operable by keyboard and announced with their current selection.
- Variant-specific price, weight, and shipping differences are reflected before checkout.
- The feature matches the existing design system.
- No existing functionality is broken.
Related features
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
Help Text Pattern
Help Text Pattern
Put field guidance in one predictable place, phrased the same way every time.
What it does
A consistent treatment for the short explanatory text that sits with a field and its control.
How it works
- 1 Collect the guidance the app currently scatters across placeholders, tooltips, asterisked footnotes, and modal help, and move it into one slot beneath the field.
- 2 Keep guidance that is required to complete the field permanently visible. A format rule hidden behind a hover target is not available to a touch user or a keyboard user.
- 3 Write help as the rule the user needs before typing — the accepted format, the consequence of the choice — not as a restatement of the label.
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/help-text-pattern
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.