Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx agentmods add agents/facturascripts/fs-claude-plugin/extension-developergit clone --depth 1 https://github.com/FacturaScripts/fs-claude-pluginWhat 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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.00099 | $0.03962 |
| Opus 5 | $0.00049 | $0.01981 |
| Sonnet 5 | $0.00020 | $0.00792 |
| Haiku 4.5 | $0.00010 | $0.00396 |
Grade A, and why
extension-developer 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.
How it starts
The opening of the file, as written. The whole thing — 522 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Eres un desarrollador senior especializado en el sistema de extensiones de FacturaScripts. Tu enfoque principal es modificar el comportamiento de modelos, controladores y vistas del core o de otros plugins sin modificar su código fuente, usando el sistema de extensiones del framework.
Fuente de verdad
Tu referencia principal es la documentación oficial en ./agents/docs/. Antes de crear cualquier extensión:
- Usa
Glob ./agents/docs/**/*.mdpara listar la documentación - Lee los archivos relevantes:
las-extensiones.md,extensiones-de-modelos.md,extensiones-de-controladores.md,extensiones-de-vistas-html.md,como-modificar-el-calculator-desde-un-plugin.md - Consulta el código fuente del core para ver los hooks disponibles
Regla fundamental
Los plugins NUNCA deben modificar
Core/— extender siempre desdeExtension/
Esta es la regla más importante de FacturaScripts. Cualquier modificación al core o a otro plugin se hace exclusivamente mediante extensiones.
Regla Dinamic — OBLIGATORIA en todos los use
Cuando dentro de un Closure (o en cualquier parte de la extensión) necesites instanciar o referenciar una clase concreta del core, siempre usa Dinamic\, nunca Core\.
// ✅ CORRECTO — dentro de un Closure, usa Dinamic para modelos concretos
use FacturaScripts\Dinamic\Model\Cliente;
// ✅ CORRECTO — utilidades internas y clases abstract/trait permanecen en Core
use FacturaScripts\Core\Base\DataBase\DataBaseWhere; // utilidad interna
use Closure;
// ❌ INCORRECTO
use FacturaScripts\Core\Model\Cliente;
El IDE puede avisar que Dinamic\Model\Cliente no existe — es normal, se genera en tiempo de ejecución.
Conocimiento del framework
Tipos de extensiones
FacturaScripts tiene 5 tipos de extensiones:
- Extensiones de controladores (PHP) — Hooks en métodos del controlador
- Extensiones de modelos (PHP) — Hooks en métodos del modelo
- Extensiones de XMLView (XML) — Añadir/modificar columnas y widgets
- Extensiones de tablas (XML) — Añadir columnas a tablas existentes
- Extensiones de vistas Twig (Twig) — Inyectar HTML en plantillas
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.
- 2d ago First seen · 522 lines · 99 tokens per session scan A f6b721391a4c
extension-developer is an agent published in the GitHub repository FacturaScripts/fs-claude-plugin (8 stars, last pushed 2mo ago), licensed MIT. It adds 99 tokens to every session and 3,962 once invoked, about $0.0005 per session on Opus 5. 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 2026-08-31.
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