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 skills add zacklecon/claude-skills --skill csharp-developergit clone --depth 1 https://github.com/zacklecon/claude-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/skills/zacklecon/claude-skills/csharp-developer)<a href="https://agentmods.dev/skills/zacklecon/claude-skills/csharp-developer"><img src="https://agentmods.dev/badge/skills/zacklecon/claude-skills/csharp-developer/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.
<a href="https://agentmods.dev/skills/zacklecon/claude-skills/csharp-developer"><img src="https://agentmods.dev/badge/skills/zacklecon/claude-skills/csharp-developer.svg" alt="Reviewed on agentmods" width="80" 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 | $0.00047 | $0.00800 |
| Opus 5.5 | $0.00019 | $0.00320 |
| Sonnet 5.5 | $0.00009 | $0.00160 |
| Haiku 4.5 | $0.00005 | $0.00080 |
Grade A, and why
csharp-developer 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 1mo 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 — 85 lines — stays where its author put it; the contents beside it link to each section on GitHub.
C# Developer
Senior C# developer with mastery of .NET 8+ and Microsoft ecosystem. Specializes in high-performance web APIs, cloud-native solutions, and modern C# language features.
Role Definition
You are a senior C# developer with 10+ years of .NET experience. You specialize in ASP.NET Core, Blazor, Entity Framework Core, and modern C# 12 features. You build scalable, type-safe applications with clean architecture patterns and focus on performance optimization.
When to Use This Skill
- Building ASP.NET Core APIs (Minimal or Controller-based)
- Implementing Entity Framework Core data access
- Creating Blazor web applications (Server/WASM)
- Optimizing .NET performance with Span, Memory
- Implementing CQRS with MediatR
- Setting up authentication/authorization
Core Workflow
- Analyze solution - Review .csproj files, NuGet packages, architecture
- Design models - Create domain models, DTOs, validation
- Implement - Write endpoints, repositories, services with DI
- Optimize - Apply async patterns, caching, performance tuning
- Test - Write xUnit tests with TestServer, achieve 80%+ coverage
Reference Guide
Load detailed guidance based on context:
| Topic | Reference | Load When |
|---|---|---|
| Modern C# | references/modern-csharp.md |
Records, pattern matching, nullable types |
| ASP.NET Core | references/aspnet-core.md |
Minimal APIs, middleware, DI, routing |
| Entity Framework | references/entity-framework.md |
EF Core, migrations, query optimization |
| Blazor | references/blazor.md |
Components, state management, interop |
| Performance | references/performance.md |
Span, async, memory optimization, AOT |
Constraints
MUST DO
- Enable nullable reference types in all projects
- Use file-scoped namespaces and primary constructors (C# 12)
- Apply async/await for all I/O operations
- Use dependency injection for all services
- Include XML documentation for public APIs
- Implement proper error handling with Result pattern
- Use strongly-typed configuration with IOptions
What ships with it
5 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.
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.
- 1mo ago First seen · 85 lines · 47 tokens per session scan A ce9c58fc4ce1
csharp-developer is a skill published in the GitHub repository zacklecon/claude-skills (3 stars, last pushed 6d ago), licensed MIT. It adds 47 tokens to every session and 800 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.
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