Variant Class Generator
Declare a component's variants once instead of scattering conditionals through its markup.
What it adds
A declarative variant definition per component mapping size, tone, and state to the classes each combination produces.
What your agent is told to do
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What your agent is told to do
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Find the components whose markup is threaded with conditional class logic and replace that logic with a single declaration listing each variant, its options, and its default.
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Support combinations that are more than the sum of their parts, so a specific pairing of size and tone can produce classes that neither produces alone, without reintroducing a conditional in the markup.
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Make invalid combinations impossible to express rather than merely undesirable, and give the component a defined appearance when it receives a combination it does not recognise.
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Publish the variant options as the component's contract for callers while keeping the class strings themselves private, so the classes can be changed without touching a single call site.
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Hand the final composition of the generated classes with caller-supplied ones to Class Merge Helper rather than resolving precedence here. This feature decides which classes a variant produces; that one decides which classes win.
Edge cases it handles
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Edge cases it handles
7- Compound variants are the reason hand-written conditionals appear in the first place — the small size in the destructive tone needing a different border, and nothing else needing it. If the declaration cannot express that pairing, the conditional comes straight back into the markup.
- Combinations that are not meant to exist, such as a ghost tone with an elevated surface, must be rejected at authoring time. Left permitted, they will be used, and the component will be expected to support them forever.
- Generated output must not become one large object that pulls every component's variants into every bundle. Keep each component's definition independently removable so unused ones never ship.
- The types a caller sees must name the variants and their options and nothing else. Leaking the class strings into the public type makes them part of the contract and freezes them.
- Defaults must be explicit for every variant, because a component rendered with no props at all is the most common case in the app and must still look right.
- State that is not a variant — focus, hover, disabled, loading — should stay in the class definition rather than becoming a prop the caller has to pass.
- A variant added or renamed later must not silently change the appearance of existing call sites that relied on the previous default.
Definition of done
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Definition of done
9- Each converted component has one declaration covering its variants, options, and defaults.
- No conditional class logic remains in the markup of converted components.
- Compound combinations are expressible in the declaration itself.
- Invalid combinations are rejected at authoring time, and unknown values render a defined fallback.
- Unused component definitions are removed from the shipped bundle.
- Public types expose variant names and options but not the underlying class strings.
- Final class composition is delegated to Class Merge Helper.
- The feature matches the existing design system.
- No existing functionality is broken.
Related features
Tokenized Inline Styles
Tokenized Inline Styles
Allow styles computed at runtime without letting arbitrary values escape the design system.
What it does
A constrained path for dynamically computed styles, where every value is either a design token or a number clamped to an approved range.
How it works
- 1 Find every place the app already sets a style value at runtime — progress widths, chart bar heights, avatar colours, drag positions, user-chosen accent colours — and sort them into two groups: values that must come from the token set, and values that are genuinely continuous numbers.
- 2 For the first group, accept only token names and resolve them to values at the boundary. A caller passing a raw colour or a raw pixel value should be rejected loudly in development rather than quietly rendered.
- 3 For the second group, clamp to a documented minimum and maximum and round to a sensible precision, so a percentage of 4000 or a width of 0.3847291 pixels never reaches the DOM.
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/tokenized-inline-styles
Class Merge Helper
Class Merge Helper
Combine conditional classes in one place so the last one written actually wins.
What it does
A single helper every component uses to resolve base, conditional, and caller-supplied classes into one final list.
How it works
- 1 Find every component that currently builds a class string by hand and route all of them through one helper, so the resolution rules are identical everywhere.
- 2 Define the precedence plainly: the component's own base classes lose to its variant classes, and both lose to whatever the caller passed in. A caller that supplies a class expects it to take effect.
- 3 Accept the shapes calling code actually produces rather than forcing every call site to normalise first, and make the behaviour for absent and empty values explicit rather than incidental.
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/class-merge-helper
CSS Module Boundaries
CSS Module Boundaries
Keep each component's styles its own, and make the shared parts deliberate.
What it does
A boundary around each component's styles, exposing only a named set of hooks that callers are permitted to style through.
How it works
- 1 Identify the primitives the rest of the app builds on — button, field, card, menu, table — and treat everything inside them as private unless it is deliberately published.
- 2 For each primitive, publish an explicit surface: the variants it accepts, the slots a caller may target, and the custom properties it reads. Anything not on that list is internal and may change without notice.
- 3 Find the places where product screens currently reach into a primitive's internals and rewrite them to use the published surface, adding a variant or a slot where the need is legitimate.
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/css-module-boundaries
How it works
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Copy the link
Grab the Markdown instruction URL for this feature.
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Give it to your AI
Paste it into Claude Code, Cursor, v0, Lovable — whatever you build with.
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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.