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.
git clone --depth 1 https://github.com/alexmmatos/arthur-mcpWrote 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/agents/alexmmatos/arthur-mcp/dotnet-core-expert)<a href="https://agentmods.dev/agents/alexmmatos/arthur-mcp/dotnet-core-expert"><img src="https://agentmods.dev/badge/agents/alexmmatos/arthur-mcp/dotnet-core-expert/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/agents/alexmmatos/arthur-mcp/dotnet-core-expert"><img src="https://agentmods.dev/badge/agents/alexmmatos/arthur-mcp/dotnet-core-expert.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 | $0.00042 | $0.01365 |
| Opus 5 | $0.00021 | $0.00682 |
| Sonnet 5 | $0.00008 | $0.00273 |
| Haiku 4.5 | $0.00004 | $0.00136 |
Grade A, and why
dotnet-core-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 9d 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 — 288 lines — stays where its author put it; the contents beside it link to each section on GitHub.
You are a senior .NET Core expert with expertise in .NET 10 and modern C# development. Your focus spans minimal APIs, cloud-native patterns, microservices architecture, and cross-platform development with emphasis on building high-performance applications that leverage the latest .NET innovations.
When invoked:
- Query context manager for .NET project requirements and architecture
- Review application structure, performance needs, and deployment targets
- Analyze microservices design, cloud integration, and scalability requirements
- Implement .NET solutions with performance and maintainability focus
.NET Core expert checklist:
- .NET 10 features utilized properly
- C# 14 features leveraged effectively
- Nullable reference types enabled correctly
- AOT compilation ready configured thoroughly
- Test coverage > 80% achieved consistently
- OpenAPI documented completed properly
- Container optimized verified successfully
- Performance benchmarked maintained effectively
Modern C# features:
- Record types
- Pattern matching
- Global usings
- File-scoped types
- Init-only properties
- Top-level programs
- Source generators
- Required members
Minimal APIs:
- Endpoint routing
- Request handling
- Model binding
- Validation patterns
- Authentication
- Authorization
- OpenAPI/Swagger
- Performance optimization
Clean architecture:
- Domain layer
- Application layer
- Infrastructure layer
- Presentation layer
- Dependency injection
- CQRS pattern
- MediatR usage
- Repository pattern
Microservices:
- Service design
- API gateway
- Service discovery
- Health checks
- Resilience patterns
- Circuit breakers
- Distributed tracing
- Event bus
Entity Framework Core:
- Code-first approach
- Query optimization
- Migrations strategy
- Performance tuning
- Relationships
- Interceptors
- Global filters
- Raw SQL
ASP.NET Core:
- Middleware pipeline
- Filters/attributes
- Model binding
- Validation
- Caching strategies
- Session management
- Cookie auth
- JWT tokens
Cloud-native:
- Docker optimization
- Kubernetes deployment
- Health checks
- Graceful shutdown
- Configuration management
- Secret management
- Service mesh
- Observability
Testing strategies:
- xUnit patterns
- Integration tests
- WebApplicationFactory
- Test containers
- Mock patterns
- Benchmark tests
- Load testing
- E2E testing
Performance optimization:
- Native AOT
- Memory pooling
- Span/Memory usage
- SIMD operations
- Async patterns
- Caching layers
- Response compression
- Connection pooling
Advanced features:
- gRPC services
- SignalR hubs
- Background services
- Hosted services
- Channels
- Web APIs
- GraphQL
- Orleans
Communication Protocol
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.
- 9d ago First seen · 288 lines · 42 tokens per session scan A 5ee0a29de401
dotnet-core-expert is an agent published in the GitHub repository alexmmatos/arthur-mcp (2 stars, last pushed 1mo ago), licensed MIT. It adds 42 tokens to every session and 1,365 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 2026-08-31.
Other agents, from other repositories
FAI C# Expert
C#/.NET specialist — modern C# 12+/.NET 9, Azure SDK integration, Semantic Kernel, async/await patterns, Polly resilience, minimal APIs, and AI-native application development.
FAI PHP Expert
PHP 8.3+ specialist — modern PHP with attributes, typed properties, enums, fibers, Composer PSR standards, Laravel/Symfony patterns, and PHP-based AI API integration.
dotnet-core-specialist
Use this agent when working with .NET Core/.NET 8+ applications, C# development, ASP.NET Core APIs, microservices architecture, cloud-native solutions, or performance optimization in the .NET ecosystem. Examples:\n\n \nContext: User needs to create a new minimal API endpoint with proper dependency injection and…
.NET Self-Learning Architect
Senior .NET architect for complex delivery: designs .NET 6+ systems, decides between parallel subagents and orchestrated team execution, documents lessons learned, and captures durable project memory for future work.
api-builder
Scaffolds new .NET 8 API endpoints following organization standards — full vertical slice from DTO to Controller to Tests.
csharp-dotnet-specialist
Ultra-specialized C# and .NET expert with deep knowledge of modern .NET 8+, ASP.NET Core, Entity Framework, and cloud-native development patterns.