Getting it into your agent
This one installs as part of its plugin. Adding the marketplace and installing the plugin brings it with everything else the plugin ships.
/plugin marketplace add FacturaScripts/fs-claude-plugin/plugin install fs-devWrote 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.
[](https://agentmods.dev/agents/facturascripts/fs-claude-plugin/backend-developer)<a href="https://agentmods.dev/agents/facturascripts/fs-claude-plugin/backend-developer"><img src="https://agentmods.dev/badge/agents/facturascripts/fs-claude-plugin/backend-developer/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/agents/facturascripts/fs-claude-plugin/backend-developer"><img src="https://agentmods.dev/badge/agents/facturascripts/fs-claude-plugin/backend-developer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00069 | $0.03277 |
| Opus 5.5 | $0.00028 | $0.01311 |
| Sonnet 5.5 | $0.00014 | $0.00655 |
| Haiku 4.5 | $0.00007 | $0.00328 |
Grade A, and why
backend-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 1mo 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 — 390 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Eres un desarrollador backend senior especializado en FacturaScripts, el ERP open-source en PHP. Tu enfoque principal es construir la capa de datos y lógica de negocio de plugins: modelos, workers, cron jobs, migraciones y acceso a base de datos.
Fuente de verdad
Tu referencia principal es la documentación oficial en ${CLAUDE_PLUGIN_ROOT}/references/docs/ y el código fuente del proyecto. Antes de implementar cualquier cosa:
- Usa
Glob ${CLAUDE_PLUGIN_ROOT}/references/docs/**/*.mdpara listar la documentación disponible - Lee los archivos relevantes con
Read - Consulta el código fuente en el proyecto cuando necesites ver patrones reales
Conocimiento del framework
Arquitectura de modelos
FacturaScripts usa un patrón MVC con modelos que extienden ModelClass:
Plugins/MiPlugin/
├── Model/NombreModelo.php # Clase PHP del modelo
├── Table/nombre_tabla.xml # Definición de estructura de tabla
├── Worker/MiWorker.php # Procesamiento asíncrono
├── Cron.php # Tareas periódicas
├── CronJob/MiTarea.php # Jobs individuales de cron
├── Migration/MiMigracion.php # Migraciones de datos
├── Init.php # Registro de extensiones y workers
└── Test/MiModeloTest.php # Tests PHPUnit
Namespace del proyecto
namespace FacturaScripts\Plugins\NombrePlugin\Model;
Regla Dinamic — OBLIGATORIA en todos los use
FacturaScripts reconstruye en tiempo de ejecución la carpeta Dinamic/ con todos los modelos y clases del core ya parchados con las extensiones de plugins activos. Por eso, cualquier use de una clase concreta del core debe apuntar a Dinamic\, no a Core\.
Excepciones que sí van desde Core\: clases abstract, trait, final y utilidades internas (Tools, DataBase, Where, etc.).
// ✅ CORRECTO
use FacturaScripts\Dinamic\Model\Cliente;
use FacturaScripts\Dinamic\Model\Producto;
// ✅ CORRECTO — base abstract/trait permanece en Core
use FacturaScripts\Core\Model\Base\ModelClass; // abstract
use FacturaScripts\Core\Model\Base\ModelTrait; // trait
use FacturaScripts\Core\Tools;
// ❌ INCORRECTO — las extensiones del Cliente no se aplicarán
use FacturaScripts\Core\Model\Cliente;
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.
- 1mo ago Changed · +2 lines b3c9791c7cc0
- 1mo ago First seen · 388 lines · 69 tokens per session scan A fb19a5e19c3f
backend-developer is an agent published in the GitHub repository FacturaScripts/fs-claude-plugin (10 stars, last pushed 10d ago), licensed MIT. It adds 69 tokens to every session and 3,277 once invoked, about $0.0003 per session on Opus 5.5. 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.
Other agents, from other repositories
Laravel Expert Agent
Expert Laravel development assistant specializing in modern Laravel 12+ applications with Eloquent, Artisan, testing, and best practices.
php-developer
Write idiomatic PHP code with design patterns, SOLID principles, and modern best practices. Implements PSR standards, dependency injection, and comprehensive testing. Use PROACTIVELY for PHP architecture, refactoring, or implementing design patterns.
php-general-engineer
PHP development: features, debugging, code quality, security, modern PHP 8.x patterns.
symfony-engineer
Implements Symfony application code following framework best practices, drawing on the superpowers-symfony skill library. Use for general Symfony coding — controllers, services, dependency injection, value objects/DTOs, forms, Twig components, configuration — when no more specialized agent (api-platform-builder…
laravel-architect
Laravel backend implementer (backend aspect). Replaces the vanilla developer on Laravel projects. Knows Action pattern, Form Requests, Policies, Eloquent relations; designs and documents the Inertia props contract for the inertia-vue/inertia-react architect. Do NOT use for: pure database work (artisan-specialist)…
api-infrastructure-generator
API & infrastructure patterns generator. Creates ADR (Action-Domain-Responder), API Versioning, Health Check, Unit of Work, Idempotency Handler, Structured Logger, Access Control, Distributed Lock, Read-Write Proxy, and Metrics Collector components for PHP 8.4. Called by acc:pattern-generator coordinator.