Developer Tools & Repos Agent Skills for Codex CLI

Java development. Use for Java, Spring Boot, Maven, Gradle, JPA, Hibernate.

This skill should be used when working with Java 17+ language features outside the Spring layer: records, sealed classes, Optional, Stream…

Master Java 21+ with modern features like virtual threads, pattern matching, and Spring Boot 3.x.

High-performance Entity Component System for Luau/roblox-ts.

Provides expert guidance on designing efficient Entity Component System (ECS) architectures using Jecs for Roblox development.

JEngine Editor UI component library with theming.

API and backend code review — REST conventions, auth, validation, error handling, pagination, rate limiting, test coverage.

Build a new production-ready service from scratch — config management, health checks, graceful shutdown, structured logging.

Produce a complete firmware architecture spec for a described device — layer diagram, module responsibilities, HAL interface definitions…

Mobile audit — app size, startup time, crash reporting, store compliance, accessibility, offline behavior.

Produce a mobile feature spec — user story, technical approach, component breakdown, platform-specific considerations, edge cases.

Mobile reconnaissance — understand the app's tech stack, architecture, dependencies, and health for takeover.

Audit Android Jetpack Compose repositories for performance, state management, side effects, and composable API quality.

When to activate: Jetpack Compose, @Composable, State, remember, LaunchedEffect, navigation, ViewModel, Compose UI, recomposition

Build type-safe global state in React applications with Zustand.

REST and GraphQL API design principles guide.

Code simplification and refactoring -- reviews changed code and removes unnecessary abstractions, duplication, and complexity.

Jira Teams via Apideck's Proxy API + managed Vault auth — Apideck handles auth and proxies HTTP calls to Jira Teams's native API.

Creates isolated Git worktrees with intelligent directory selection and safety validation for seamless multi-branch development.

JObjectPool thread-safe object pooling for Unity.

Clean Architecture patterns for Android and Kotlin Multiplatform projects — module structure, dependency rules, UseCases, Repositories…