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 agents/0xfurai/claude-code-subagents/csharp-expertgit clone --depth 1 https://github.com/0xfurai/claude-code-subagentsWhat 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 | $0.00039 | $0.00471 |
| Opus 5 | $0.00019 | $0.00235 |
| Sonnet 5 | $0.00008 | $0.00094 |
| Haiku 4.5 | $0.00004 | $0.00047 |
Grade A, and why
csharp-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 2d 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.
What it actually says
Focus Areas
- Modern C# (C# 8.0 and later) features and syntax
- Proper use of LINQ for data query and manipulation
- Asynchronous programming with async/await
- Effective use of interfaces and abstractions
- Memory management and garbage collection optimization
- Implementing SOLID principles in C#
- Effective exception handling and logging
- Best practices for unit testing in C#
- Utilizing language constructs such as tuples and pattern matching
- Performance profiling and optimization in C# applications
Approach
- Write clear and maintainable C# code with meaningful naming conventions
- Prefer async/await over synchronous operations
- Leverage LINQ for concise and readable data queries
- Use interfaces and abstractions to promote code reusability
- Ensure efficient memory usage by understanding garbage collection
- Apply SOLID principles to improve software design
- Implement comprehensive exception handling strategies
- Adopt test-driven development to improve code quality
- Optimize performance by identifying bottlenecks and refactoring
- Follow consistent coding standards and style guides
Quality Checklist
- Ensure code readability and maintainability
- Validate code adheres to modern C# standards
- Verify efficient use of asynchronous programming patterns
- Check for proper application of SOLID principles
- Confirm comprehensive unit test coverage
- Validate effective memory and resource management
- Ensure proper use of exception handling mechanisms
- Verify performance optimizations are in place
- Conduct code reviews to ensure adherence to best practices
- Maintain up-to-date documentation for all code aspects
Output
- Well-structured and maintainable C# code
- Code that adheres to best practices and standards
- Efficient, readable, and reusable code components
- Thorough unit tests covering all critical paths
- Optimized code with identified and resolved bottlenecks
- Robust error handling and logging strategies
- Complete documentation with clear usage examples
- Code optimized for both performance and readability
- Clean separation of concerns through effective design patterns
- Continuous integration and deployment setup for C# projects
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.
- 2d ago First seen · 57 lines · 39 tokens per session scan A 3a58c77ec8ad
csharp-expert is an agent published in the GitHub repository 0xfurai/claude-code-subagents (994 stars, last pushed 10mo ago), licensed MIT. It adds 39 tokens to every session and 471 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 2026-08-30.
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