Implement WorkManager and Background Processing correctly on Android. Use when creating Worker classes, scheduling tasks with WorkManager, choosing between WorkManager and Foreground Services, or setting up Hilt in workers. (triggers: **/*Worker.kt, CoroutineWorker, WorkManager, doWork, PeriodicWorkRequest, OneTimeWorkRequest, @HiltWorker)

Harden Intent handling, WebView configuration, and FileProvider access in Android apps. Use when securing Intent extras, configuring WebViews, or exposing files via FileProvider. (triggers: **/*Activity.kt, **/*WebView*.kt, AndroidManifest.xml, Intent, WebView, FileProvider, javaScriptEnabled)

Apply Clean Architecture layering, modularization, and Unidirectional Data Flow in Android projects. Use when setting up Android project structure, placing code in Clean Architecture layers, configuring feature/core modules, or implementing UDF patterns. (triggers: build.gradle.kts, settings.gradle.kts, clean-architecture, module, layers, domain, UDF, unidirectional, feature module, core module, presentation layer, data layer)

Configure Angular Router with lazy-loaded routes, functional guards, and component input binding. Use when defining routes, lazy-loading features, creating route guards, or setting up resolvers. (triggers: *.routes.ts, angular router, loadComponent, canActivate, resolver)

Standards for Coroutines, Flow, and Threading. Use when writing suspend functions, choosing coroutine scopes, switching between StateFlow and SharedFlow, injecting Dispatchers for testability, or debugging threading issues in Android. (triggers: **/*ViewModel.kt, **/*UseCase.kt, **/*Repository.kt, suspend, viewModelScope, lifecycleScope, Flow, coroutine, Dispatcher, DispatcherProvider, GlobalScope)

Configure ViewModel state emission with StateFlow, sealed UiState classes, and lifecycle-safe collection in Android. Use when working with ViewModel files, UiState sealed classes, MutableStateFlow, collectAsStateWithLifecycle, or exposing state from ViewModels. (triggers: **/*ViewModel.kt, **/*UiState.kt, viewmodel, stateflow, livedata, uistate, MutableStateFlow, collectAsState, viewModelScope, UiState)

Configure Hilt dependency injection with proper scoping, modules, and constructor injection in Android. Use when setting up Hilt DI, component scoping, or defining modules. (triggers: **/*Module.kt, **/*Component.kt, @HiltAndroidApp, @Inject, @Provides, @Binds)

Delegate coding tasks to Codex, Claude Code, or Pi agents via background process. Use when: (1) building/creating new features or apps, (2) reviewing PRs (spawn in temp dir), (3) refactoring large codebases, (4) iterative coding that needs file exploration. NOT for: simple one-liner fixes (just edit), reading code (use read tool), thread-bound ACP harness requests in chat (for example spawn/run Codex or Claude Code in a Discord thread; use sessions_spawn with runtime:"acp"), or any work in ~/clawd workspace (never spawn agents here). Claude Code: use --print --permission-mode bypassPermissions (no PTY). Codex/Pi/OpenCode: pty:true required.

Use when creating Nuxt modules: (1) Published npm modules (@nuxtjs/, nuxt-), (2) Local project modules (modules/ directory), (3) Runtime extensions (components, composables, plugins), (4) Server extensions (API routes, middleware), (5) Releasing/publishing modules to npm, (6) Setting up CI/CD workflows for modules. Provides defineNuxtModule patterns, Kit utilities, hooks, E2E testing, and release automation.

Use when building NuxtHub v0.10.6 applications - provides database (Drizzle ORM with sqlite/postgresql/mysql), KV storage, blob storage, and cache APIs. Covers configuration, schema definition, migrations, multi-cloud deployment (Cloudflare, Vercel), and the new hub:db, hub:kv, hub:blob virtual module imports.

Annotate Airflow tasks with data lineage using inlets and outlets. Use when the user wants to add lineage metadata to tasks, specify input/output datasets, or enable lineage tracking for operators without built-in OpenLineage extraction.

Workflow and best practices for writing Apache Airflow DAGs. Use when the user wants to create a new DAG, write pipeline code, or asks about DAG patterns and conventions. For testing and debugging DAGs, see the testing-dags skill.

Guide for migrating Apache Airflow 2.x projects to Airflow 3.x. Use when the user mentions Airflow 3 migration, upgrade, compatibility issues, breaking changes, or wants to modernize their Airflow codebase. If you detect Airflow 2.x code that needs migration, prompt the user and ask if they want you to help upgrade. Always load this skill as the first step for any migration-related request.

Verify that interface and class contracts (preconditions, postconditions, invariants) are preserved across program versions. Use when validating refactorings, checking API compatibility, verifying design-by-contract implementations, or ensuring behavioral contracts remain intact after code changes. Automatically detects contract violations, identifies affected methods and classes, and provides actionable guidance for resolving violations while maintaining program correctness.

Extract abstract mathematical models from functional code (Haskell, OCaml, F#) for formal reasoning in Isabelle/HOL. Use when users need to: (1) Convert functional programs to Isabelle definitions, (2) Extract high-level algorithm essence from implementation code, (3) Generate formal specifications and properties from code, (4) Create verification-ready models that capture mathematical properties while abstracting away implementation details. Focuses on structural recursion, algebraic data types, higher-order functions, and invariant extraction.

Generate unit tests with proper mocking for Python (unittest.mock/pytest) or Java (Mockito/JUnit) code. Use when users request test generation, unit tests with mocks, or testing code that has external dependencies like database calls, API requests, file I/O, or network operations. Automatically identifies dependencies to mock and creates executable, maintainable test code.

Profile programs at the function/method level to identify performance hotspots, bottlenecks, and optimization opportunities. Records execution time, memory usage, and call frequency for each interval. Generates actionable recommendations and visualizations. Use when users need to (1) analyze program performance, (2) identify slow functions or bottlenecks, (3) optimize execution time or memory usage, (4) profile Python, Java, or C/C++ programs with test cases or workload scenarios, or (5) generate performance reports with flame graphs and recommendations.

Restructure and improve Isabelle or Coq proofs to enhance readability, modularity, and maintainability without changing semantics. Use when proofs are long and monolithic, have repeated patterns, use unclear naming, lack documentation, or when the user asks to refactor, clean up, improve, or reorganize their formal proofs.

Automatically migrate Python web applications between frameworks (Flask → FastAPI, Django → FastAPI). Use when you need to migrate an existing web application to a modern framework while preserving functionality. The skill analyzes the codebase, updates routes, handlers, configuration, dependency injection patterns, and tests. Creates git commits for each migration phase and generates a comprehensive summary of all changes. Supports automatic dependency updates, code transformations, and test adaptations.

Recommend relevant Isabelle/HOL or Coq standard library theories, lemmas, and tactics based on proof goals. Use when: (1) Users need library lemmas for their proof, (2) Proof goals match standard library patterns, (3) Users ask what libraries to import, (4) Specific lemmas are needed for list/set/arithmetic operations, (5) Users are stuck and need to know what library support exists, or (6) Guidance on find_theorems/Search commands is needed. Supports both Isabelle/HOL and Coq standard libraries.