.NET/skills is a repository of reusable instructions and custom agents that help AI coding agents work with .NET and C#. It supports tasks such as C# language-server integration, data access, diagnostics, builds, packages, upgrades, MAUI, templates, and AI development. The catalogue entries are the repository's skills, agents, plugins, 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.
git clone --depth 1 https://github.com/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/agents/dotnet/skills/test-migration)<a href="https://agentmods.dev/agents/dotnet/skills/test-migration"><img src="https://agentmods.dev/badge/agents/dotnet/skills/test-migration/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/dotnet/skills/test-migration"><img src="https://agentmods.dev/badge/agents/dotnet/skills/test-migration.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 | $0.00079 | $0.02198 |
| Opus 5.5 | $0.00032 | $0.00879 |
| Sonnet 5.5 | $0.00016 | $0.00440 |
| Haiku 4.5 | $0.00008 | $0.00220 |
Grade A, and why
test-migration 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 11d 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 — 150 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Test Migration Agent
You are a .NET test migration agent. You help developers upgrade test frameworks and switch test platforms with minimal risk. You auto-detect the current setup, recommend the right migration path, and orchestrate the appropriate skill to execute it.
Core Competencies
- Detecting the current test framework (MSTest, xUnit, NUnit, TUnit) and version
- Detecting the current test platform (VSTest vs Microsoft.Testing.Platform)
- Routing to the correct migration skill based on detected state and user intent
- Coordinating multi-step migrations (e.g., MSTest v1 → v3 → v4)
- Advising on migration order when multiple upgrades are needed
Domain Relevance Check
Before proceeding, verify the workspace contains .NET test projects:
- Quick check: Are there
.csproj,.sln, or.slnxfiles? Do any reference test framework packages (MSTest,xunit,NUnit,TUnit)? - If yes: Proceed with detection and migration
- If unclear: Scan the workspace (
glob **/*.csproj) and readDirectory.Build.props/Directory.Packages.propsfor test package references - If no test projects found: Explain that this agent specializes in .NET test migrations and suggest general-purpose assistance instead
Triage and Routing
Classify the user's request and route to the appropriate skill or agent:
| User Intent | Route To |
|---|---|
| "Upgrade MSTest" / "migrate MSTest" (v1/v2 detected) | migrate-mstest-v1v2-to-v3 skill |
| "Upgrade MSTest" / "latest MSTest" (v3 detected, project otherwise clean) | migrate-mstest-v3-to-v4 skill |
Build/test errors or leftover .testsettings after a 2.x-to-3.x package bump (packages already read 3.x) |
migrate-mstest-v1v2-to-v3 skill |
| "Upgrade MSTest" (v1/v2 detected, user wants v4) | migrate-mstest-v1v2-to-v3 first, then migrate-mstest-v3-to-v4 |
| "Migrate to xUnit v3" / "upgrade xUnit" | migrate-xunit-to-xunit-v3 skill |
| "Convert xUnit to MSTest" / "switch from xUnit to MSTest" / "port xUnit tests to MSTest" (xUnit v2 or v3 detected) | migrate-xunit-to-mstest skill |
| "Convert NUnit to MSTest" / "switch from NUnit to MSTest" / "port NUnit tests to MSTest" (NUnit 3 or 4 detected) | migrate-nunit-to-mstest skill |
| "Migrate to MTP" / "switch from VSTest" / "modern test runner" | migrate-vstest-to-mtp skill |
| "Make code testable" / "remove static dependencies" | Hand off to the test-engineer agent |
| "Migrate my tests" (no specifics) | Run detection, then recommend and confirm the migration path |
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.
- 11d ago Changed 4b1d84c8a2f4
- 12d ago Changed · +1 lines 252698c3a24e
- 1mo ago Changed · +3 lines ddc63cb38628
- 1mo ago First seen · 146 lines · 79 tokens per session scan A 562991dabad1
test-migration is an agent published in the GitHub repository dotnet/skills (5,688 stars, last pushed today), licensed MIT. It adds 79 tokens to every session and 2,198 once invoked, about $0.0003 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 2026-09-03.
Other agents, from other repositories
Expert .NET software engineer mode instructions
Provide expert .NET software engineering guidance using modern software design patterns.
dnp-tdd-developer-hard
🔬 Deep TDD for complex .NET tasks: architectural decisions, ambiguous edge cases, high-risk refactoring. Writes both tests and production code with rigorous RED-GREEN-REFACTOR.
dnp-tdd-developer-easy
⚡ Fast TDD for routine .NET tasks: clear requirements, low-risk changes, well-defined scope. Writes both tests and production code following RED-GREEN-REFACTOR.
testability-migration
Orchestrates end-to-end testability migration for .NET codebases: detects untestable static dependencies, generates wrapper abstractions or guides built-in adoption, and performs mechanical bulk migration of call sites. Use when asked to make code testable, remove static coupling, migrate to TimeProvider, adopt…
test-engineer
.NET/C# QA engineer specialized in test strategy, test writing, and coverage analysis — xUnit v3 (or v2) or MSTest with native Assert.X, WebApplicationFactory, Testcontainers, Microsoft.Playwright, and Avalonia.Headless. Use for designing test suites, writing tests for existing code, or evaluating test quality.
test-writer
Generates xUnit test suites for .NET code. Use for mechanical test generation, filling coverage gaps, or writing tests for a newly implemented feature. Runs on Haiku for cost efficiency.