A coding agent focused on C# and the .NET platform. It covers code design, asynchronous programming, performance, errors, and newer C# features.

Use it to design or review C# applications, apply SOLID principles and design patterns, handle asynchronous code and errors, improve performance, and use modern C# features.

It helps when you need .NET code that follows established design and maintenance practices.

How AndreasKarz/Vibe-Coding-Dev-Setup configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to AndreasKarz/Vibe-Coding-Dev-Setup. 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/AndreasKarz/Vibe-Coding-Dev-Setup/main/.github/agents/CSharpExpert.agent.md

Clone the repo

git clone --depth 1 https://github.com/AndreasKarz/Vibe-Coding-Dev-Setup

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.

README.md

[![agentmods](https://agentmods.dev/badge/agents/andreaskarz/vibe-coding-dev-setup/csharpexpert/github.svg)](https://agentmods.dev/agents/andreaskarz/vibe-coding-dev-setup/csharpexpert)

Your own site

<a href="https://agentmods.dev/agents/andreaskarz/vibe-coding-dev-setup/csharpexpert"><img src="https://agentmods.dev/badge/agents/andreaskarz/vibe-coding-dev-setup/csharpexpert/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.

Your own site · 80×15

<a href="https://agentmods.dev/agents/andreaskarz/vibe-coding-dev-setup/csharpexpert"><img src="https://agentmods.dev/badge/agents/andreaskarz/vibe-coding-dev-setup/csharpexpert.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 44 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.

When invoked 1,399 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 unknown 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.

Model	Per session	Once invoked
Fable 5.1	$0.00044	$0.01399
Opus 5.5	$0.00018	$0.00560
Sonnet 5.5	$0.00009	$0.00280
Haiku 4.5	$0.00004	$0.00140

Measured 2mo ago against content hash 172c95ff102b, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

C# Expert 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 2mo 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.

.github/agents/CSharpExpert.agent.md · 132 lines

The source is not reproduced here

A licence we could not identify

The repository carries a LICENSE file, but it is custom or dual enough that GitHub cannot name it and neither can this catalogue. Unknown terms are not permission, so the body is not copied here. Read the licence at the source and decide for yourself.

Read it on GitHub

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.

2mo ago First seen · 132 lines · 44 tokens per session scan A 172c95ff102b

Subscribe to this mod's changes

C# Expert is an agent published in the GitHub repository AndreasKarz/Vibe-Coding-Dev-Setup (7 stars, last pushed 8mo ago), with no licence file. It adds 44 tokens to every session and 1,399 once invoked, about $0.0002 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.

C# and .NET Languages agentic-coding copilot-agents copilot-instructions copilot-prompts copilot-skills vibe-coding

C# Expert next to 6 agents from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
C# ExpertAndreasKarz/Vibe-Coding-Dev-Setup	Agent	7	8mo ago	none	A	44	Claude Code
Technical Program Managerandreaswasita/copilot-agents-dojo	Agent	54	2mo ago	MIT	A	53	Claude Code
Architectandreaswasita/copilot-agents-dojo	Agent	54	2mo ago	MIT	A	46	Claude Code
Business Architectandreaswasita/copilot-agents-dojo	Agent	54	2mo ago	MIT	A	45	Claude Code
Platform Architectandreaswasita/copilot-agents-dojo	Agent	54	2mo ago	MIT	A	57	Claude Code
Solution Architectandreaswasita/copilot-agents-dojo	Agent	54	2mo ago	MIT	A	46	Claude Code
Security Engineerandreaswasita/copilot-agents-dojo	Agent	54	2mo ago	MIT	A	15	Claude Code

Vibe-Coding-Dev-Setup: Agent for Claude Code