neo-csharp

neo-csharp is a skill for Claude Code, Codex from Benknightdark/neo-skills. It costs 65 tokens per session (1,329 once invoked), scanned A, original, MIT.

A set of instructions for writing, reviewing, debugging, and updating C# code in .NET projects. It checks the project’s .NET version so the code uses language features that the project supports.

In plain words
What is it for?
Use it for C# files, .csproj projects, .NET 6 or newer applications, and code modernization or review work.
Why use it?
It helps avoid incompatible syntax and gives consistent guidance for modern C# features such as nullable references, records, pattern matching, and asynchronous code.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it for C# files, .csproj projects, .NET 6 or newer applications, and code modernization or review work.

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Install with agentmods
npx agentmods add skills/benknightdark/neo-skills/neo-csharp
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 Benknightdark/neo-skills --skill neo-csharp
Clone the repo
git clone --depth 1 https://github.com/Benknightdark/neo-skills

Made for: Claude Code, 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 neo-csharp

README.md
[![agentmods](https://agentmods.dev/badge/skills/benknightdark/neo-skills/neo-csharp/github.svg)](https://agentmods.dev/skills/benknightdark/neo-skills/neo-csharp)
Your own site
<a href="https://agentmods.dev/skills/benknightdark/neo-skills/neo-csharp"><img src="https://agentmods.dev/badge/skills/benknightdark/neo-skills/neo-csharp/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.

agentmods 80×15 button for neo-csharp

Your own site · 80×15
<a href="https://agentmods.dev/skills/benknightdark/neo-skills/neo-csharp"><img src="https://agentmods.dev/badge/skills/benknightdark/neo-skills/neo-csharp.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 65 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,329 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 $0.00065 $0.01329
Opus 5 $0.00032 $0.00665
Sonnet 5 $0.00013 $0.00266
Haiku 4.5 $0.00006 $0.00133

Measured 10d ago against content hash f093c0fed7e5, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

neo-csharp 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 10d 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.

skills/neo-csharp/SKILL.md · 93 lines

How it starts

The opening of the file, as written. The whole thing — 93 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Modern C# (10+) Expert Skill

Trigger On

  • The user asks to write, debug, refactor, or review C# code.
  • The project directory contains *.cs, *.csproj, or single-file C# scripts.
  • The target framework is .NET 6.0 (LTS) and above.
  • Code modernization is needed (e.g., converting legacy nested namespaces to File-scoped namespaces).

Workflow

  1. Perceive (Version Awareness):
    • Check .csproj to identify TargetFramework and determine the syntax upper limit:
      • net6.0: C# 10 (File-scoped namespaces, Global usings).
      • net7.0: C# 11 (Raw string literals, Required members).
      • net8.0: C# 12 (Primary Constructors, Collection Expressions).
      • net9.0: C# 13 (params collections, Lock object).
      • net10.0: C# 14 (Extension members, field keyword).
  2. Reason (Planning Phase):
    • Evaluate the modernization level of the current code to determine the refactoring strategy.
    • In lower version environments (like .NET 6), avoid using higher version syntax (like Primary Constructors), but prioritize using File-scoped namespaces.
    • In higher version environments, actively adopt new features to reduce boilerplate code.
  3. Act (Execution Phase):
    • Write high-quality code, prioritizing "syntactic sugar" to improve readability.
    • Implement strong typing and immutable data structures (record, record struct).
    • Utilize Interpolated string handlers and Span to optimize performance-sensitive paths.
  4. Validate (Standard Validation):
    • Validate the safety of NRT (Nullable Reference Types).
    • Check if asynchronous operations correctly handle cancellation tokens (CancellationToken).
    • Ensure naming conventions comply with official .NET recommendations.

Feature Roadmap (C# 10 - 14)

C# 10 & 11 (Foundation)

  • File-scoped Namespaces: Reduce indentation levels.
  • Global Using Directives: Centralize common namespaces management.
  • Raw String Literals: """...""" easily handle multi-line and special characters.
  • Required Members: Ensure required properties during object initialization.
  • List Patterns: if (list is [1, 2, ..]) powerful collection matching.

Read the full file on GitHub · 93 lines

Files

What ships with it

3 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. 10d ago First seen · 93 lines · 65 tokens per session scan A f093c0fed7e5

Subscribe to this mod's changes

neo-csharp is a skill published in the GitHub repository Benknightdark/neo-skills (7 stars, last pushed 4d ago), licensed MIT. It adds 65 tokens to every session and 1,329 once invoked, about $0.0003 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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