software-csharp-backend

software-csharp-backend is a skill for Codex from vasilyu1983/AI-Agents-public. It costs 34 tokens per session (3,435 once invoked), scanned A, original, MIT.

A guide to building backend applications with C# and .NET, covering APIs, databases, background workers, resilience, documentation, and security.

In plain words
What is it for?
Use it when designing ASP.NET Core APIs, choosing EF Core or Dapper, adding workers and retries, or planning .NET data access.
Why use it?
It helps developers make consistent technology and architecture choices for .NET services and avoid common reliability problems.

Skill for Codex

Written for Codex: agents/openai.yaml present. Also seen: mentions Claude Code; mentions Codex; $skill-name invocation.

Good fit Use it when designing ASP.NET Core APIs, choosing EF Core or Dapper, adding workers and retries, or planning .NET data access.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/vasilyu1983/ai-agents-public/software-csharp-backend
Install

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.

Any agent
npx skills add vasilyu1983/AI-Agents-public --skill software-csharp-backend
Clone the repo
git clone --depth 1 https://github.com/vasilyu1983/AI-Agents-public

Made for: Codex.

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 software-csharp-backend

README.md
[![agentmods](https://agentmods.dev/badge/skills/vasilyu1983/ai-agents-public/software-csharp-backend.svg)](https://agentmods.dev/skills/vasilyu1983/ai-agents-public/software-csharp-backend)
Your own site
<a href="https://agentmods.dev/skills/vasilyu1983/ai-agents-public/software-csharp-backend"><img src="https://agentmods.dev/badge/skills/vasilyu1983/ai-agents-public/software-csharp-backend.svg" alt="Measured on agentmods" height="20"></a>
Per session 34 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,435 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. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
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 $0.00034 $0.03435
Opus 5 $0.00017 $0.01717
Sonnet 5 $0.00007 $0.00687
Haiku 4.5 $0.00003 $0.00344

Measured 4d ago against content hash fdefea813e3d, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

software-csharp-backend 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 4d 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.

frameworks/shared-skills/skills/software-csharp-backend/SKILL.md · 215 lines

How it starts

The opening of the file, as written. The whole thing — 215 lines — stays where its author put it; the contents beside it link to each section on GitHub.

C# Backend Engineering

Quick Reference

Decision Default Notes
Runtime .NET 10 + C# 14 (LTS, GA Nov 2025, supported through ~Nov 2028) .NET 8 LTS ends Nov 10, 2026 — verify current dates at dotnet support policy; treat continued .NET 8 targeting as a tracked migration, not a comfortable steady state
API style Minimal API for new endpoints Controllers for large CQRS surface with many filters/action results
Persistence (SQL, write-heavy) EF Core Use Dapper when query shapes are complex and hand-tuned SQL wins
Persistence (SQL, query-heavy) Dapper Pair with EF Core for write path if aggregates exist
Persistence (document) MongoDB driver Use when schema variability is genuine, not habitual
Background worker IHostedService / BackgroundService Add lease, graceful shutdown, and poison-message handling from day one
Resilience Microsoft.Extensions.Resilience (Polly v8) Standard pipeline: retry → circuit breaker → timeout
OpenAPI Built-in ASP.NET Core OpenAPI (Microsoft.AspNetCore.OpenApi) Do not add Swashbuckle unless repo already uses it

Route other tasks:

  • NUnit fixture design, WireMock/Testcontainers setup, or flake reduction → $qa-testing-nunit
  • nuke/Build.cs, CI target sequencing, or artifact publication → $ops-nuke-cicd
  • Legacy ILogger or Serilog rewrite automation → $dev-structured-logs

When to Use This Skill

  • Building or reviewing C# / .NET backend services
  • Choosing between ASP.NET Core API styles (controller, minimal API, background worker)
  • Implementing data access with EF Core, Dapper, or MongoDB
  • Adding resilience, observability, or security baselines to .NET services
  • Refactoring .NET backend code or detecting common anti-patterns

When NOT to Use This Skill

Read the full file on GitHub · 215 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. 4d ago First seen · 215 lines · 34 tokens per session scan A fdefea813e3d

Subscribe to this mod's changes

software-csharp-backend is a skill published in the GitHub repository vasilyu1983/AI-Agents-public (86 stars, last pushed 5d ago), licensed MIT. It adds 34 tokens to every session and 3,435 once invoked, about $0.0002 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 2026-09-03.

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