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~/skills/framework/ ls

Camel Route Developer

Apache Camel route development guidance from a Camel committer, covering route design, integration patterns, endpoint configuration, and practical implementation checks for JVM integration applications.

by Zineb Bendhiba
java
apache-camel
camelintegrationroutesenterprise-integration-patterns

Dr-JSkill Spring Boot Scaffolding

Scaffold Spring Boot projects via start.spring.io with fullstack frontend support (Vue, React, Angular, vanilla JS), PostgreSQL, Docker Compose, and Testcontainers. Follows Julien Dubois' defaults.

by Julien Dubois
kotlinjava
spring-boot
spring-bootscaffoldingproject-structurebootstrapping

Gemini Java SDK

Typed Gemini Java SDK usage from the SDK author, with Java examples and SDK-native interaction patterns rather than generic REST operations.

by Guillaume Laforge
java
geminijava-sdk
aisdkgeminijava

jabrena JVM Collection

Curated JVM skill collection covering Quarkus, Micronaut, modern Java, Maven, testing, observability, profiling, and related framework practices. Uses self-contained skill directories with co-located references and verified APIs.

by Juan Antonio Breña
java
quarkusmicronautmaventestingobservability
javaframeworkcollectionquarkusmicronautmaven

Jakarta EE / MicroProfile Server

Adam Bien's guidance for building Jakarta EE and MicroProfile servers, filling the directory's Jakarta EE gap with concise, practical JVM server conventions.

by Adam Bien
java
jakarta-eemicroprofile
jakarta-eemicroprofileserverjava

Native Firebase in KMP

Kotlin Multiplatform Firebase integration using native Android and iOS SDKs through an interface-injection pattern, avoiding third-party KMP wrappers while keeping shared contracts clean.

by dyor
kotlin
kotlin-multiplatformfirebase
kmpfirebaseandroidiosarchitecture

Project Reactor

Expert guidance for Project Reactor on the JVM: operator selection (Mono, Flux, flatMap vs concatMap, switchMap, zip, expand), schedulers and threading, backpressure tuning, Reactor Context propagation (MDC, Micrometer, Spring Security), blocking-to-reactive bridging, R2DBC patterns and reactive transactions, WebClient/reactor-netty configuration, Kotlin coroutine/Flow interop, testing with StepVerifier, and debugging with checkpoint/log/ReactorDebugAgent/BlockHound.

by Aditya Parikh
javakotlin
reactorreactivewebfluxmonofluxr2dbcwebclient

Quarkus Extension Development

Quarkus extension development guidance with build-time/runtime separation, extension structure, version-specific behavior, and verified LTS deltas.

by Zineb Bendhiba
java
quarkus
quarkusextensionsbuild-timeruntime

Quarkus + LangChain4j Scaffolding

Quarkus and LangChain4j scaffolding guidance with real in-directory templates for building JVM agentic applications on Quarkus.

by Elder Moraes
java
quarkuslangchain4j
quarkuslangchain4jagentsscaffolding

Restart Spring Boot

Restart the app via IntelliJ run configuration and wait until ready. Skips restart for template changes where LiveReload handles it automatically.

by jvm-skills
kotlinjava
spring-boot
spring-bootdevelopmenthot-reload

Spring Batch 6 Migration

Version-pinned Spring Batch 6 guidance for writing new batch jobs, migrating from 5.x, reviewing API changes, and debugging Spring Batch applications.

by Anton Arhipov
javakotlin
spring-batchspring-framework
spring-batchmigrationbatchspring

Spring Boot 4 Migration

Migrates Spring Boot 3.x applications to 4.x and tracks 4.x minor-version changes. Covers build/starter changes, Jackson 3, Spring Security 7, Spring Framework 7, observability (OpenTelemetry/Micrometer), property and package relocations, testing (JUnit 6, Testcontainers 2, MockitoBean), HTTP clients, resilience, AOT/native, and API versioning. Includes all-at-once and gradual upgrade strategies with compatibility bridges and a verification script.

by Aditya Parikh
javakotlingroovy
spring-bootmigrationspring-frameworkspring-securityjackson

Spring Boot 3.x Enterprise

Enterprise Spring Boot 3.x patterns: layered architecture with constructor injection, Spring Security with OAuth2, Spring Data JPA repositories, Actuator health checks, and integration testing with @SpringBootTest.

by Piotr Minkowski
java
spring-bootspring-securityspring-data
spring-bootrest-apispring-securityspring-datamicroservicesactuator

Spring Boot 4.x (SivaLabs scaffolding)

Opinionated Spring Boot 4.x modular-monolith scaffolding (SivaLabs style): package-by-feature + Spring Modulith boundaries, Thymeleaf server-side rendering, ArchUnit/Taikai architecture tests, Docker Compose dev services, and a Maven build-quality setup (Spotless, JaCoCo gate, buildpacks). Maven-only, Boot 4.x.

by K. Siva Prasad Reddy
javakotlin
spring-bootspring-datathymeleafmavendocker
spring-bootspring-mvcspring-dataspring-moduliththymeleaftestingarchunitdocker-compose

Spring Boot Version-Aware Development

Version-aware Spring Boot coding across the 3.5.x↔4.0.x boundary — detects Boot/Java versions and applies the right APIs (Jackson 2/3, @MockitoBean vs @MockBean, built-in @GetMapping versioning), plus virtual-thread discipline, JSpecify/NullAway build wiring (Maven + Gradle), and Micrometer/OpenTelemetry observability. Delegates deep migration/JSpecify to sibling skills.

by Aditya Parikh
java
spring-bootspringversion-detectionvirtual-threadsnullawayobservabilitybackend

~/skills/language/ ls

Java 21 Best Practices

Comprehensive Java 21 best-practices guidance with verified APIs, opinionated implementation rules, and a broad pattern catalog that supersedes weaker code-quality and design-pattern listings.

by Stephan Janssen
java
java-21
javabest-practicescode-qualitydesign-patternsrefactoring

Java 25 Conventions

Dense, opinionated Java 25 coding conventions for modern Java applications, including concrete style, API, and implementation rules from Adam Bien.

by Adam Bien
java
java-25
javaconventionsclean-codestyle

Java LTS Upgrade Guides 8→25

A curated bundle of Java LTS upgrade guides covering 8→11, 11→17, 17→21, and 21→25 with JEP-by-JEP migration guidance and worked code examples.

by Bruno Borges
java
java-8java-11java-17java-21java-25
javaupgrademigrationltsjep

Kotlin API Design Review

Kotlin API design and binary-compatibility review guidance, including default-argument ABI behavior, @JvmOverloads limits, @PublishedApi, explicit API mode, and compatibility validation.

by Baruch Sadogursky
kotlin
kotlin
kotlinapi-designbinary-compatibilitycode-review

Kotlin 2.2/2.3 Language Features

Kotlin language-feature guidance covering recent Kotlin 2.2 and 2.3 behavior, with verified feature details and practical usage advice for modern Kotlin/JVM code.

by Anton Arhipov
kotlin
kotlin-2
kotlinlanguage-featuresmigrationkotlin-2

Java Logging Patterns

Logging best practices with SLF4J, structured JSON logging, and MDC for request tracing. Includes AI-friendly log formats optimized for Claude Code debugging and correlation ID patterns.

by Piotr Minkowski
java
slf4j
loggingslf4jstructured-loggingmdcjson-loggingdebugging

Java Optional Skill

Java Optional best practices for implementation, review, and cleanup. Covers Optional shape selection, isPresent()+get() and orElse(null) antipatterns, lazy fallback with orElseGet(...), primitive Optionals, stream interop, findFirst()/findAny() semantics, and checked-IO boundaries.

by François Martin
java
optionalnull-safetyfunctional-programmingcode-reviewrefactoringclean-code

POJO to Data-Class Refactor Safety

Kotlin refactoring guidance for safely converting Java POJOs to data classes, including componentN ordering, public API compatibility, sensitive toString exposure, and field-order hazards.

by Baruch Sadogursky
javakotlin
kotlin
kotlinrefactoringdata-classjava

Java Streams Skill

Java Streams, Collectors, and Gatherers best practices for implementation, review, and cleanup. Covers terminal operation choice, ordering and null behavior, collector semantics, primitive streams, duplicate-key and comparator pitfalls, Java-version-specific APIs, and when parallelStream() is actually appropriate.

by François Martin
java
streamscollectorsfunctional-programmingcode-reviewrefactoringclean-codeparallel-streams

~/skills/database/ ls

Design PostgreSQL Tables

Comprehensive reference covering PostgreSQL table design, data types, indexing strategies, constraints, JSONB patterns, partitioning, and PostgreSQL-specific best practices. Covers update-heavy, upsert-heavy, and OLTP-style table patterns.

by TimescaleDB
kotlinjava
postgresql
postgresschematable-designindexingjsonbconstraintspartitioning

Hibernate JPA Validator

Reviews Hibernate/JPA code in the spirit of Hypersistence Optimizer: identifier strategies, entity mappings, association and fetch design, N+1 detection, query optimization, batch processing, transactions and locking, Spring Data JPA anti-patterns, schema migrations, and Hibernate 6 features. Runs the full checklist on every entity review.

by Aditya Parikh
java
hibernatejpaormdatabaseperformancevalidation

jOOQ Best Practices

Comprehensive jOOQ DSL best practices for Kotlin/Java. Expert knowledge base covering SQL patterns, transactions, multiset nesting, code generation, Spring Boot integration, and PostgreSQL-specific features.

by jvm-skills
kotlinjava
spring-bootjooqpostgresql
jooqsqldsldatabasepostgrestransactionsmultiset

Oracle OKafka Java Clients

Oracle OKafka Java-client guidance with JVM-specific client configuration, examples, and integration patterns for Oracle Database-backed Kafka APIs.

by Anders Swanson
java
oracle-databaseokafka
oraclekafkadatabasejava-client

pgvector Semantic Search

Setting up vector similarity search with pgvector for AI/ML embeddings, RAG applications, or semantic search. Covers halfvec storage, HNSW index configuration, quantization strategies, filtered search, and performance tuning.

by TimescaleDB
kotlinjava
postgresqlpgvector
pgvectorembeddingssemantic-searchvector-similarityhnswragllm

PostgreSQL Hybrid Text Search

Implementing hybrid search combining BM25 keyword search with semantic vector search using Reciprocal Rank Fusion (RRF). Covers pg_textsearch BM25 index setup, parallel query patterns, client-side RRF fusion, and optional ML reranking.

by TimescaleDB
kotlinjava
postgresqlbm25
hybrid-searchbm25pg_textsearchrrfkeyword-searchfull-text-searchreranking

~/skills/testing/ ls

Compose Desktop UI Testing

Compose Desktop UI testing through an HTTP control server, using a real Maven Central library and reusable testing patterns without project-specific Release Wizard coupling.

by Mr3zee
kotlin
compose-desktopui-testing
composedesktoptestingui

Kover Gradle Coverage

Run Kover coverage via Gradle, identify packages and classes below coverage thresholds, and generate a prioritized test improvement plan.

by jvm-skills
kotlinjava
gradlekover
gradlekovercoveragetest-analysis

JDB Agentic Debugger

Multi-agent debugger orchestrator that drives JDB CLI to set breakpoints, step through code, and collect thread dumps. Each capability is packaged as a reusable agent skill, making the toolkit readily callable from AI coding agents.

by Bruno Borges
kotlinjava
jdb
debuggingjdbbreakpointsthread-dumps

Kotest

Write a new Kotlin test, or modernize an existing one, using Kotest matchers and idiomatic Kotlin test style — backticked names, apply/assertSoftly blocks, and existing object mothers and helpers. Preserves assertion semantics when modernizing, and verifies with a focused test command. Framework-neutral — project-specific context (base classes, test annotations, single-test command) plugs in via a local `references/project.md` overlay.

by Urs Peter
kotlin
kotestjunitassertj
kotlintestingkotesttest-authoringmodernization

Mutation Testing (pitest)

Bootstrap pitest via the info.solidsoft.pitest Gradle plugin with Kotlin-sane defaults, run scoped mutation tests derived from git diff, interpret surviving mutants from mutations.xml, triage likely-equivalent mutants (logger gates, unreachable loop bounds, null-elvis on non-nullable values) into a separate bucket, and drive a kill-survivor workflow that hands each likely-killable survivor to /tdd-task. Non-intrusive — mutates bytecode, no production-code changes required.

by jvm-skills
kotlinjava
gradlepitestjunit5
mutation-testingpitesttest-qualitytdd

Ralph Coverage

Run an autonomous Ralph loop that improves test coverage by iteratively picking the least-covered class, writing meaningful tests for it, and committing — one class per iteration until a target threshold is reached. Ships a single-run script and a headless N-iteration loop.

by jvm-skills
kotlinjava
gradlekoverralph
coverageralphautonomoustdd

TDD Task

Implement a feature or fix a bug using strict TDD — plan a todolist, clarify ambiguities before coding, write a failing test first, then implement the minimum to pass, refactor, verify (with an E2E test for user-observable changes), and commit. Enforces red-green-refactor with mandatory gates.

by jvm-skills
kotlinjava
spring-boot
tddtestingred-green-refactorworkflow

Gradle Test Runner

Run Gradle tests headlessly with optional filter patterns. Returns raw failure output to the caller — does NOT fix failures. Fix-or-report separation keeps test runs cheap and predictable.

by jvm-skills
kotlinjavagroovy
gradle
gradletestingtddtest-runner

UI Review

Verify UI/UX by running Playwright tests and reviewing screenshots. Spawns a ui-review subagent to check layouts, user flows, and visual correctness. Iterates until the page looks right.

by jvm-skills
kotlinjavagroovy
playwright
uitestingscreenshotsvisual-review

~/skills/fullstack/ ls

Fullstack Fix

TDD-driven bug fixing: write a failing test first, implement the fix, refactor, then verify. Automatically picks the right test type — integration with DB, mocks/stubs, or end-to-end browser.

by jvm-skills
kotlinjava
spring-boot
tddspring-boottestingbug-fixing

~/skills/web/ ls

Frontend Design

Break out of generic AI-generated UIs. Opinionated design system covering typography scales, color themes, motion choreography, spatial composition, and layered background effects.

by Anthropic
html
frontenddesignuiuxanimationstypographycss

Web Performance Optimization

Optimize web performance for faster loading and better user experience. Covers Core Web Vitals, critical rendering path, image optimization, font loading strategies, caching, and third-party script management.

by Addy Osmani
html
performancewebcore-web-vitalsoptimization

~/skills/workflow/ ls

Commit

Group uncommitted changes into logical feature commits with concise, action-oriented messages. Avoids conventional commit prefixes.

by jvm-skills
kotlinjavagroovy
gitcommitversion-control

Feature Interview

Interview user relentlessly about a plan or design until reaching shared understanding, resolving each branch of the decision tree. Outputs a spec with user stories that cover all roles, entry points, and edge cases.

by jvm-skills
kotlinjava
planninginterviewuser-storiesrequirements
\n

Rebase Commit

Rebase non-pushed commits and uncommitted changes into clean logical feature commits using vertical-slice grouping. Preserves incremental slices as separate commits while merging related fixes.

by jvm-skills
kotlinjavagroovy
gitrebasecommitversion-control

Spec-Driven Development Bundle

Six-step spec-driven development workflow bundle for turning a proposal into acceptance criteria, rules, review, task plans, and execution checkpoints. Listed as a cohesive workflow bundle rather than isolated generic workflow singles.

by Anton Arhipov
javakotlin
specificationacceptance-criteriaworkflowplanningimplementation

Spec

Generate a feature spec with user stories from conversation context and codebase exploration. Proactively resolves unknowns by mining conversation, exploring code, and reading docs — no interview needed.

by jvm-skills
kotlinjavagroovy
specplanninguser-storiesrequirements

~/skills/tool/ ls

Agent Browser

Browser automation CLI for AI agents. Navigate, fill forms, click, take screenshots, scrape data, and run exploratory QA via Chrome/Chromium over CDP. Covers browsers, Electron apps, Slack, and cloud browser backends.

by Vercel Labs
javascripttypescript
browserautomationtestingqascreenshotsscraping

Java 25 Single-File Scripting

Zero-dependency Java 25 single-file scripting guidance with shebang execution, PATH installation, and practical CLI patterns without a build tool.

by Adam Bien
java
java-25
javacliscriptingsingle-file

JFR Recording Analysis

Java Flight Recorder analysis workflow for offline .jfr recordings, covering event-type semantics, native jfr CLI usage, lock contention, allocation, GC, and noise-filtering strategies.

by Victor Rentea
java
jfrjvm
profilingjfrperformancediagnostics

JSpecify Nullability

JSpecify provides annotations to explicitly declare nullness expectations of Java code. Adds jspecify dependency and configures Maven or Gradle builds with ErrorProne/NullAway for compile-time nullability checking. Helps prevent NullPointerExceptions.

by K. Siva Prasad Reddy
java
jspecifyerrorprone
nullabilityerrorpronenullawaynpe-prevention

jstall JVM Live Diagnostics

JVM live diagnostics with jstall: deadlock detection, flame graphs, GC and classloader analysis, JIT queue inspection, and focused commands for investigating running Java processes.

by Johannes Bechberger
java
jstalljvm
diagnosticsprofilingdeadlocksflamegraphsgc

Kotlin REPL Prototyping

Kotlin REPL prototyping workflow using kotlinc -Xrepl and focused experimentation techniques for Kotlin/JVM code before committing changes.

by Simon Vergauwen
kotlin
kotlinrepl
kotlinreplprototypingexperimentation

MavenToGradle

Migrates Maven JVM projects to Gradle Kotlin DSL with version catalogs, covering single-module and multi-module builds, Spring Boot parent POMs, Maven profiles, dependency scope mapping, BOM imports, annotation processors, plugin mappings, and dual-build overlay mode.

by Aditya Parikh
kotlinjava
buildmavengradle

Konveyor MTA Migration Analysis

Java codebase migration assessment using Konveyor MTA and kantra, including custom rules, target platform analysis, blocker detection, and effort estimation for JVM migrations.

by sshaaf
java
konveyormtakantra
migrationanalysisjava-eequarkusspring-boot

macOS Notarization for JavaFX and jpackage

Transferable macOS signing and notarization workflow for JavaFX/jpackage applications, including jlink, notarytool, and JVM-native crash-diagnostic considerations.

by Bruno Borges
java
javafxjpackagemacos
notarizationsigningjavafxjpackagemacos

qs-kotlin

Guidance for using the qs-kotlin query-string library with its verified defaults and source-backed API behavior, focused on Kotlin/JVM request serialization and parsing.

by Techouse
kotlin
qs-kotlin
kotlinquery-stringserializationhttp

Malicious PDF Validation

JVM PDF security validation with Apache PDFBox, covering attachments, XFA, JavaScript, launch and GoToR links, import actions, concatenation detection, and file-size safeguards.

by Dominique Righetto
java
pdfbox
securitypdfpdfboxvalidation

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One-liner bootstrap

curl -fsSL jvmskills.com/install | sh — auto-detects your stack from build files, picks matching skills, and generates AI config. Zero dependencies.

Compose, don't duplicate

Skills compose from a base + language/database overlays. Detect jOOQ + Kotlin + PostgreSQL? You get the base skill plus only the overlays that matter.

Every AI tool

Claude Code is the v1 target. The same skill content compiles to Cursor, Copilot, Windsurf, Aider, and Codex formats — one source of truth, every editor.