.NET Skills is an AI coding plugin that provides skills and specialized guidance for professional .NET development, covering areas such as C#, Akka.NET, Aspire, Entity Framework Core, testing, and performance. .NET developers use it with coding assistants to apply production-oriented patterns while building and maintaining applications. The catalogue contains the plugin’s skills, agents, and instructions.
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 instructions/aaronontheweb/dotnet-skills/agents-mdgit clone --depth 1 https://github.com/Aaronontheweb/dotnet-skillsWrote 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/instructions/aaronontheweb/dotnet-skills/agents-md)<a href="https://agentmods.dev/instructions/aaronontheweb/dotnet-skills/agents-md"><img src="https://agentmods.dev/badge/instructions/aaronontheweb/dotnet-skills/agents-md.svg" alt="Measured on agentmods" 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 | $0.01291 | $0.01291 |
| Opus 5 | $0.00646 | $0.00646 |
| Sonnet 5 | $0.00258 | $0.00258 |
| Haiku 4.5 | $0.00129 | $0.00129 |
Grade A, and why
dotnet-skills AGENTS.md 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 6d 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 — 130 lines — stays where its author put it; the contents beside it link to each section on GitHub.
AGENTS.md
This file provides guidance to AI coding agents (Claude Code, Codex, OpenCode, and others) when working in this repository. It is the canonical file; CLAUDE.md is a symlink to it.
Repository Purpose
Canonical repository: https://github.com/Aaronontheweb/dotnet-skills
This is the official marketplace for .NET development skills and agents, covering the entire .NET ecosystem: C#, F#, MSBuild, NuGet, Aspire, testing frameworks, and specialized tools like DocFX and BenchmarkDotNet.
This is a knowledge base repository - not a traditional code project. There is no build system, tests, or compiled output.
Structure
dotnet-skills/
├── .claude-plugin/
│ ├── marketplace.json # Claude Code marketplace catalog
│ └── plugin.json # Claude Code plugin metadata + skill/agent registry
├── .codex-plugin/
│ └── plugin.json # Codex plugin metadata (skills auto-discovered from ./skills/)
├── .agents/
│ └── plugins/
│ └── marketplace.json # Codex marketplace
├── skills/ # Flat structure for Copilot compatibility
│ ├── akka-best-practices/SKILL.md
│ ├── aspire-integration-testing/SKILL.md
│ ├── csharp-coding-standards/SKILL.md
│ ├── testcontainers/SKILL.md
│ └── ...
├── agents/ # Agent definitions (flat .md files, Claude Code only)
└── scripts/ # Validation and sync scripts
Skill Naming Convention
Skills use a flat directory structure with prefixes for framework-specific skills:
akka-*- Akka.NET skillsaspire-*- .NET Aspire skillscsharp-*- C# language skillsmicrosoft-extensions-*- Microsoft.Extensions.* packagesplaywright-*- Playwright-specific skills- No prefix for general .NET skills (e.g.,
testcontainers,efcore-patterns)
File Formats
Skills are folders with SKILL.md:
---
name: skill-name
description: Brief description used for matching
---
Agents are markdown files with YAML frontmatter:
---
name: agent-name
description: Brief description used for matching
model: sonnet # sonnet, opus, or haiku
color: purple # optional
---
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.
- 6d ago First seen · 130 lines · 1,291 tokens per session scan A c9de7cb5d17c
dotnet-skills AGENTS.md is an instructions file published in the GitHub repository Aaronontheweb/dotnet-skills (1,140 stars, last pushed 29d ago), licensed MIT. It adds 1,291 tokens to every session, about $0.0065 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 2026-08-30.
Other instructions, from other repositories
maui performance-hotpaths.instructions.md
Instructions for dotnet/maui, covering performance-critical path rules, hot paths in maui, allocation avoidance, caching and invalidation and collection iteration.
maui-labs testing.instructions.md
Instructions for dotnet/maui-labs, covering testing guide, test framework, test projects, running tests and all tests.
Kucoin.Net copilot-instructions.md
Copilot instructions for JKorf/Kucoin.Net, covering copilot instructions for kucoin.net, use kucoin.net, not raw http, client setup, result handling and api structure.
coinex-net
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MonorailCss.Framework CLAUDE.md
Claude Code instructions for monorailcss/MonorailCss.Framework, covering monorailcss, architecture overview, core components, key design patterns and project structure.
unity-code-style-guide AGENTS.md
Instructions for krogh-jacobsen/unity-code-style-guide, covering agents.md — unity 6 c, project setup — edit this block, never do these — they corrupt the project, deprecated in unity 6 and if you read nothing else.