SvelteKit UI Integration

Purpose

Implement or extend user-facing workflows in SvelteKit applications, leveraging SvelteKit's full-stack capabilities including load functions, form actions, and API routes. Follow SvelteKit conventions for routing, state management, and progressive enhancement.

When to use this skill

• The feature is primarily a UI/UX change leveraging SvelteKit's architecture.
• Building progressive enhancement with server-side rendering and client-side interactivity.
• The backend contracts, auth model, and core business rules already exist or will be implemented as SvelteKit API routes.
• The change affects only the SvelteKit application (no external service changes).

Inputs

• Feature description: short narrative of the user flow and outcomes.
• Relevant APIs: endpoints, request/response types, and links to source definitions.
• Target routes/components: paths, component names, or feature modules.
• Design references: Figma links or existing screens to mirror.
• Guardrails: performance limits, accessibility requirements, and any security constraints.

Out of scope

• Creating new backend services or changing persistent data models.
• Modifying authentication/authorization flows.
• Introducing new frontend frameworks or design systems.

Conventions

• Framework: SvelteKit with TypeScript.
• Routing: use SvelteKit's file-based routing with +layout.svelte, +page.svelte, and +page.server.ts.
• Styling: Use shadcn-svelte, Skeleton UI, or Melt UI components (via shadcn-svelte-management skill) or the in-house design system components.

When using UI components, invoke the shadcn-svelte-management skill to:

• Discover available Svelte components
• Get component installation commands
• Choose appropriate component library (shadcn-svelte, Skeleton UI, Melt UI)
• State management: prefer Svelte stores, reactive statements, and SvelteKit's form actions.
• Data fetching: use SvelteKit load functions for server-side data and progressive enhancement.

Required behavior

1. Implement the UI changes with strong typing for all props, load function data, and form actions.
2. Handle loading, empty, error, and success states using SvelteKit's $page.form and reactive statements.
3. Ensure the UI is keyboard accessible and screen-reader friendly with proper ARIA attributes.
4. Leverage SvelteKit's progressive enhancement - works without JavaScript, enhanced with it.
5. Respect feature flags and rollout mechanisms where applicable.

Required artifacts

• Updated components and actions in the appropriate feature module (src/lib/components/).
• Load functions in +page.server.ts or +layout.server.ts for server-side data.
• Form actions for handling form submissions with progressive enhancement.
• Unit tests for core presentation logic and Svelte stores.
• Integration or component tests for the new flow (e.g., Svelte Testing Library, Cypress, Playwright) where the repo already uses them.
• Minimal CHANGELOG or PR description text summarizing the behavior change (to be placed in the PR, not this file).

Implementation checklist

1. Locate the relevant feature module and existing components in src/lib/components/.
2. Confirm the backend APIs and types, updating shared TypeScript types if needed.
3. Implement the UI with SvelteKit patterns:
   • Use +page.server.ts for server-side data loading
   • Use form actions for POST/PUT/DELETE operations
   • Leverage +layout.svelte for shared UI elements
   • Implement progressive enhancement
4. Add or update tests to cover the new behavior and edge cases.
5. Run the required validation commands (see below).

Verification

Run the following (adjust commands to match the project):

• pnpm lint
• pnpm test -- --runInBand --watch=false
• pnpm check (SvelteKit type checking)
• pnpm build (to verify production build)
• pnpm preview (test production build locally)

The skill is complete when:

• All tests, linters, and type checks pass.
• The new UI behaves as specified across normal, error, and boundary cases.
• Progressive enhancement works (functional without JavaScript).
• Form submissions work with and without JavaScript.
• No unrelated files or modules are modified.

Safety and escalation

• If the requested change requires external backend contract changes, stop and request a backend-focused task instead.
• If design references conflict with existing accessibility standards, favor accessibility and highlight the discrepancy in the PR description.
• Always implement with progressive enhancement in mind - ensure functionality works without JavaScript.