LeTrain: Skill for OpenCode

.opencode/skills/java-expert-mentor/SKILL.md

java-expert-mentor is a skill for OpenCode from antoniovazquezaraujo/LeTrain. It costs 0 tokens per session (298 once invoked), scanned A, original, Apache-2.0.

A Java 17 mentoring guide covering object-oriented programming, design patterns, SOLID principles, LibGDX, and Lanterna. SOLID is a set of principles for keeping code easier to change and maintain.

In plain words
What is it for?
Use it to analyse Java architecture, choose or review design patterns, integrate LibGDX or Lanterna, and check code for unnecessary coupling or abstraction.
Why use it?
It gives architecture and refactoring work a consistent review process instead of relying on ad hoc design decisions.

Skill for OpenCode

Written for OpenCode: installed under .opencode/.

This is antoniovazquezaraujo/LeTrain's own configuration. It tells OpenCode how to work on LeTrain itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything LeTrain configures →

Reuse

Borrowing it

Nothing to install: this file belongs to antoniovazquezaraujo/LeTrain. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/antoniovazquezaraujo/LeTrain/develop/.opencode/skills/java-expert-mentor/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/antoniovazquezaraujo/LeTrain

Made for: OpenCode.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for java-expert-mentor

README.md
[![agentmods](https://agentmods.dev/badge/skills/antoniovazquezaraujo/letrain/java-expert-mentor.svg)](https://agentmods.dev/skills/antoniovazquezaraujo/letrain/java-expert-mentor)
Your own site
<a href="https://agentmods.dev/skills/antoniovazquezaraujo/letrain/java-expert-mentor"><img src="https://agentmods.dev/badge/skills/antoniovazquezaraujo/letrain/java-expert-mentor.svg" alt="Measured on agentmods" height="20"></a>
Per session 0 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 298 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00000 $0.00298
Opus 5 $0.00000 $0.00149
Sonnet 5 $0.00000 $0.00060
Haiku 4.5 $0.00000 $0.00030

Measured 2d ago against content hash b9fae0c9afdd, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

java-expert-mentor scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.opencode/skills/java-expert-mentor/SKILL.md · 26 lines

What it actually says

name: java-expert-mentor description: Skill de mentoría técnica para Java 17, POO, patrones de diseño, LibGDX y Lanterna. Úsala para análisis de arquitectura, refactorización y aplicación de principios SOLID.

Java Expert Mentor

Esta skill proporciona conocimiento experto sobre:

  1. Patrones de Diseño y POO: Aplicación de SOLID, patrones de comportamiento (como el Visitor ya presente en el proyecto), y principios de abstracción en Java 17.
  2. Ecosistema LeTrain: Mejores prácticas para integrar LibGDX y Lanterna.

Cómo utilizar esta Skill

1. Análisis de Arquitectura

Cuando propongas un cambio, invoca la sección de PATTERNS.md para verificar si se está aplicando un patrón adecuado o si se puede mejorar la abstracción.

2. Desarrollo con librerías

Consulta LIBRARIES.md para patrones específicos de:

  • LibGDX: Uso eficiente de recursos y renderizado.
  • Lanterna: Abstracción de terminal.

3. Revisión de Código

Aplica siempre el "Checklist de Experto" antes de finalizar cualquier tarea:

  • ¿Es el código SOLID?
  • ¿La abstracción es necesaria o prematura?
  • ¿Están correctamente desacopladas las interfaces de las implementaciones?
Files

What ships with it

2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 26 lines · 0 tokens per session scan A b9fae0c9afdd

Subscribe to this mod's changes

java-expert-mentor is a skill published in the GitHub repository antoniovazquezaraujo/LeTrain (12 stars, last pushed yesterday), licensed Apache-2.0. It costs nothing until one of its globs matches a file; then it loads 298 tokens. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-04.

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