Andes.Extensions.AI: Skill for Claude Code

.claude/skills/ef-core/SKILL.md

ef-core is a skill for Claude Code from Andes-Software-Solutions/Andes.Extensions.AI. It costs 10 tokens per session (499 once invoked), scanned A, a copy of ef-core, MIT.

A guide to best practices for Entity Framework Core, a .NET library that maps application code to database data. It covers data contexts, entities, relationships, queries, performance, and migrations.

In plain words
What is it for?
Use it when designing database models, configuring relationships, writing queries, improving performance, or creating database migrations in Entity Framework Core.
Why use it?
It helps prevent common database-design and query problems, such as unnecessary data loading and inefficient repeated queries.

Skill for Claude Code

Written for Claude Code: installed under .claude/.

This is Andes-Software-Solutions/Andes.Extensions.AI's own configuration. It tells Claude Code how to work on Andes.Extensions.AI 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 Andes.Extensions.AI configures →

Reuse

Borrowing it

Nothing to install: this file belongs to Andes-Software-Solutions/Andes.Extensions.AI. 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/Andes-Software-Solutions/Andes.Extensions.AI/main/.claude/skills/ef-core/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/Andes-Software-Solutions/Andes.Extensions.AI

Made for: Claude Code.

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 ef-core

README.md
[![agentmods](https://agentmods.dev/badge/skills/andes-software-solutions/andes.extensions.ai/ef-core.svg)](https://agentmods.dev/skills/andes-software-solutions/andes.extensions.ai/ef-core)
Your own site
<a href="https://agentmods.dev/skills/andes-software-solutions/andes.extensions.ai/ef-core"><img src="https://agentmods.dev/badge/skills/andes-software-solutions/andes.extensions.ai/ef-core.svg" alt="Measured on agentmods" height="20"></a>
Per session 10 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 499 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 100% copy Near-identical to another mod 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 $0.00010 $0.00499
Opus 5 $0.00005 $0.00249
Sonnet 5 $0.00002 $0.00100
Haiku 4.5 $0.00001 $0.00050

Measured 8d ago against content hash cab5bc6e7168, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

ef-core 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 8d 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.

Origin

This is a copy

100% identical to ef-core — 1 line differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

.claude/skills/ef-core/SKILL.md · 75 lines

How it starts

The opening of the file, as written. The whole thing — 75 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Entity Framework Core Best Practices

Your goal is to help me follow best practices when working with Entity Framework Core.

Data Context Design

  • Keep DbContext classes focused and cohesive
  • Use constructor injection for configuration options
  • Override OnModelCreating for fluent API configuration
  • Separate entity configurations using IEntityTypeConfiguration
  • Consider using DbContextFactory pattern for console apps or tests

Entity Design

  • Use meaningful primary keys (consider natural vs surrogate keys)
  • Implement proper relationships (one-to-one, one-to-many, many-to-many)
  • Use data annotations or fluent API for constraints and validations
  • Implement appropriate navigational properties
  • Consider using owned entity types for value objects

Performance

  • Use AsNoTracking() for read-only queries
  • Implement pagination for large result sets with Skip() and Take()
  • Use Include() to eager load related entities when needed
  • Consider projection (Select) to retrieve only required fields
  • Use compiled queries for frequently executed queries
  • Avoid N+1 query problems by properly including related data

Migrations

  • Create small, focused migrations
  • Name migrations descriptively
  • Verify migration SQL scripts before applying to production
  • Consider using migration bundles for deployment
  • Add data seeding through migrations when appropriate

Querying

  • Use IQueryable judiciously and understand when queries execute
  • Prefer strongly-typed LINQ queries over raw SQL
  • Use appropriate query operators (Where, OrderBy, GroupBy)
  • Consider database functions for complex operations
  • Implement specifications pattern for reusable queries

Change Tracking & Saving

  • Use appropriate change tracking strategies
  • Batch your SaveChanges() calls
  • Implement concurrency control for multi-user scenarios
  • Consider using transactions for multiple operations
  • Use appropriate DbContext lifetimes (scoped for web apps)

Security

  • Avoid SQL injection by using parameterized queries
  • Implement appropriate data access permissions
  • Be careful with raw SQL queries
  • Consider data encryption for sensitive information
  • Use migrations to manage database user permissions

Read the full file on GitHub · 75 lines

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. 8d ago First seen · 75 lines · 10 tokens per session scan A cab5bc6e7168

Subscribe to this mod's changes

ef-core is a skill published in the GitHub repository Andes-Software-Solutions/Andes.Extensions.AI (9 stars, last pushed 5d ago), licensed MIT. It adds 10 tokens to every session and 499 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. It is 100% identical to ef-core, differing in 1 line, and is treated as a copy.

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