Design and generate layered Kotlin + Spring tests that balance speed, realism, and regression value across unit, slice, and integration levels. Use when adding coverage for business logic, controllers, repositories, security, serialization, or end-to-end workflows, and when generic AI output would otherwise overuse `@SpringBootTest`, misuse mocks, or ignore MockK and coroutine testing idioms.

Use only when the user explicitly asks to stage, commit, push, and open a GitHub pull request in one flow using the GitHub CLI (`gh`).

Plan and execute risky Spring Boot, Spring Framework, Kotlin, Gradle, JDK, and major dependency upgrades with explicit compatibility checkpoints and rollback thinking. Use when preparing or diagnosing a major version jump, navigating `javax` to `jakarta`, K2 adoption, plugin compatibility, auto-configuration drift, behavior changes in Hibernate or Security, or project-specific upgrade sequencing.

Deploy applications and websites to Vercel. Use when the user requests deployment actions like "deploy my app", "deploy and give me the link", "push this live", or "create a preview deployment".

Apply VueUse composables where appropriate to build concise, maintainable Vue.js / Nuxt features.

Toolkit for interacting with and testing local web applications using Playwright. Supports verifying frontend functionality, debugging UI behavior, capturing browser screenshots, and viewing browser logs.

Design and generate Kotlin Spring HTTP APIs with correct controller signatures, DTOs, validation, serialization assumptions, error handling, and web tests. Use when building or changing REST endpoints, choosing between MVC and WebFlux, modeling request and response payloads, standardizing error responses, or avoiding Kotlin-specific validation and Jackson mistakes.

Use for Vue.js testing. Covers Vitest, Vue Test Utils, component testing, mocking, testing patterns, and Playwright for E2E testing.

Use when working with TeamCity CI/CD or when user provides a TeamCity build URL. Use `teamcity` CLI for builds, logs, jobs, queues, and agents.

Review UI code for Web Interface Guidelines compliance. Use when asked to "review my UI", "check accessibility", "audit design", "review UX", or "check my site against best practices".

Toolkit for styling artifacts with a theme. These artifacts can be slides, docs, reportings, HTML landing pages, etc. There are 10 pre-set themes with colors/fonts that you can apply to any artifact that has been creating, or can generate a new theme on-the-fly.

Vitest fast unit testing framework powered by Vite with Jest-compatible API. Use when writing tests, mocking, configuring coverage, or working with test filtering and fixtures.

Design safe transaction boundaries, rollback behavior, idempotency, locking, and consistency strategies for Kotlin + Spring business workflows. Use when a feature writes to the database, spans multiple repositories, publishes messages, calls external systems, suffers from partial commits or duplicate processing, or needs precise `@Transactional`, propagation, or isolation guidance.

Turborepo monorepo build system guidance. Triggers on: turbo.json, task pipelines, dependsOn, caching, remote cache, the "turbo" CLI, --filter, --affected, CI optimization, environment variables, internal packages, monorepo structure/best practices, and boundaries. Use when user: configures tasks/workflows/pipelines, creates packages, sets up monorepo, shares code between apps, runs changed/affected packages, debugs cache, or has apps/packages directories.

MUST be used for Vue.js tasks. Strongly recommends Composition API with `<script setup>` and TypeScript as the standard approach. Covers Vue 3, SSR, Volar, vue-tsc. Load for any Vue, .vue files, Vue Router, Pinia, or Vite with Vue work. ALWAYS use Composition API unless the project explicitly requires Options API.

Bundle TypeScript and JavaScript libraries with blazing-fast speed powered by Rolldown. Use when building libraries, generating type declarations, bundling for multiple formats, or migrating from tsup.

Vue Router 4 patterns, navigation guards, route params, and route-component lifecycle interactions.

Update website docs to match recent code changes, cross-validating every flag against source. Use this skill whenever the user asks to: update documentation, sync docs with code, document a new flag or command, fix stale docs, or update the README. This skill covers all website/docs/ categories (commands, reference, understand, how-to, troubleshooting, getting-started) plus the built-in skill description and README. If you just implemented a feature and need to update docs, this is the skill to use. Never manually edit website docs without cross-validating flags against Go source first.

Diagnose Kotlin + Spring failures from stack traces, startup logs, runtime logs, and related metric anomalies, then separate root cause from wrapper exceptions and propose safe next steps. Use when the application fails to start, an endpoint crashes, logs are noisy or deeply nested, or the agent must produce both a quick mitigation and a proper long-term fix without guessing.

Vite build tool configuration, plugin API, SSR, and Vite 8 Rolldown migration. Use when working with Vite projects, vite.config.ts, Vite plugins, or building libraries/SSR apps with Vite.