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Reference data for detecting the test platform (VSTest vs Microsoft.Testing.Platform) and test framework (MSTest, xUnit, NUnit, TUnit) from project files.
Install Platform Detection
$ npx skills add microsoft/testfx --skill platform-detection -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install microsoft/testfx platform-detection --agent claude-codeProject scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).
$ git clone --depth 1 https://github.com/microsoft/testfx.git skills-src && mkdir -p .claude/skills && cp -r skills-src/.agents/skills/platform-detection .claude/skills/platform-detection && rm -rf skills-srcUse ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.
Claude Code skills documentation · loads skills from .claude/skills/
Install the "platform-detection" agent skill from https://github.com/microsoft/testfx/tree/main/.agents/skills/platform-detection into .claude/skills/platform-detection/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "platform-detection", then confirm the skill loads.Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$skill-installer install https://github.com/microsoft/testfx/tree/main/.agents/skills/platform-detectionType this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.
$ npx skills add microsoft/testfx --skill platform-detection -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install microsoft/testfx platform-detection --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/microsoft/testfx.git skills-src && mkdir -p .agents/skills && cp -r skills-src/.agents/skills/platform-detection .agents/skills/platform-detection && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "platform-detection" agent skill from https://github.com/microsoft/testfx/tree/main/.agents/skills/platform-detection into .agents/skills/platform-detection/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "platform-detection", then confirm the skill loads.Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add microsoft/testfx --skill platform-detection -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install microsoft/testfx platform-detection --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/microsoft/testfx.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/.agents/skills/platform-detection .cursor/skills/platform-detection && rm -rf skills-srcUse ~/.cursor/skills/ instead of .cursor/skills for a personal install.
Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/
Install the "platform-detection" agent skill from https://github.com/microsoft/testfx/tree/main/.agents/skills/platform-detection into .cursor/skills/platform-detection/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "platform-detection", then confirm the skill loads.Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gemini skills install https://github.com/microsoft/testfx.git --path .agents/skills/platform-detection--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.
$ npx skills add microsoft/testfx --skill platform-detection -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install microsoft/testfx platform-detection --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/microsoft/testfx.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/.agents/skills/platform-detection .gemini/skills/platform-detection && rm -rf skills-srcUse ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.
Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/
Install the "platform-detection" agent skill from https://github.com/microsoft/testfx/tree/main/.agents/skills/platform-detection into .gemini/skills/platform-detection/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "platform-detection", then confirm the skill loads.Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gh skill install microsoft/testfx platform-detectionInstalls for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).
$ npx skills add microsoft/testfx --skill platform-detection -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/microsoft/testfx.git skills-src && mkdir -p .github/skills && cp -r skills-src/.agents/skills/platform-detection .github/skills/platform-detection && rm -rf skills-srcUse ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.
GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/
Install the "platform-detection" agent skill from https://github.com/microsoft/testfx/tree/main/.agents/skills/platform-detection into .github/skills/platform-detection/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "platform-detection", then confirm the skill loads.GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add microsoft/testfx --skill platform-detection -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install microsoft/testfx platform-detection --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/microsoft/testfx.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/.agents/skills/platform-detection .opencode/skills/platform-detection && rm -rf skills-srcUse ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.
OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/
Install the "platform-detection" agent skill from https://github.com/microsoft/testfx/tree/main/.agents/skills/platform-detection into .opencode/skills/platform-detection/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "platform-detection", then confirm the skill loads.OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
Facts
- Skill name
platform-detection- GitHub stars
- 1k
- Token cost
- ~886 tokens
- SKILL.md length
- 352 words
- Files
- 1
- Skills in repo
- 44
- Repo updated
- First seen
- Licence
- MIT
At a glance
Reference data for detecting the test platform (VSTest vs Microsoft.Testing.Platform) and test framework (MSTest, xUnit, NUnit, TUnit) from project files.
- Tasks that involve Unit testing
- SKILL.md covers Detecting the test framework and Detecting the test platform
- Calls dotnet
What it does
Platform Detection is an agent skill from microsoft/testfx, published by the product's own GitHub organization. Reference data for detecting the test platform (VSTest vs Microsoft.Testing.Platform) and test framework (MSTest, xUnit, NUnit, TUnit) from project files. DO NOT USE directly — loaded by run-tests, mtp-hot-reload, and migrate-vstest-to-mtp when they need detection logic.
Its SKILL.md is about 890 tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.
It sits in Testing & QA, covering Unit testing. It works with .NET. The repository describes itself as: This repository holds the source code of Microsoft.Testing.Platform (MTP), a lightweight alternative to VSTest, as well as MSTest adapter and framework. The licence is MIT.
When your agent uses it
- Tasks that involve Unit testing
Example prompts
- “/platform-detection”
What it can do on your machine
Read from SKILL.md and the folder at commit 44b9dcc. It shows what the files ask for, not the result of running them.
Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
Shell commands in SKILL.md call:
dotnet
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.
Context cost
Platform Detection loads about 886 tokens when it runs. Until then it costs about 73 tokens; SKILL.md has 352 words of instructions outside code blocks.
Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.
Safety
Auto-check passed
The automated check found no risky patterns in SKILL.md.
Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.
SKILL.md
The full file from microsoft/testfx at commit 44b9dcc, republished under its MIT licence (© microsoft). 352 words, ~886 tokens.
Download SKILL.mdSave it as
.claude/skills/platform-detection/SKILL.md (or your agent's skills folder).- name
- platform-detection
- description
- Reference data for detecting the test platform (VSTest vs Microsoft.Testing.Platform) and test framework (MSTest, xUnit, NUnit, TUnit) from project files. DO NOT USE directly — loaded by run-tests, mtp-hot-reload, and migrate-vstest-to-mtp when they need detection logic.
- user-invocable
- false
- license
- MIT
Test Platform and Framework Detection
Determine which test platform (VSTest or Microsoft.Testing.Platform) and which test framework (MSTest, xUnit, NUnit, TUnit) a project uses.
Detection files to always check (in order): global.json → .csproj → Directory.Build.props → Directory.Packages.props
Detecting the test framework
Read the .csproj file and Directory.Build.props / Directory.Packages.props (for centrally managed dependencies) and look for:
| Package or SDK reference | Framework |
|---|---|
MSTest (metapackage, recommended) or <Sdk Name="MSTest.Sdk"> | MSTest |
MSTest.TestFramework + MSTest.TestAdapter | MSTest (also valid for v3/v4) |
xunit, xunit.v3, xunit.v3.mtp-v1, xunit.v3.mtp-v2, xunit.v3.core.mtp-v1, xunit.v3.core.mtp-v2 | xUnit |
NUnit + NUnit3TestAdapter | NUnit |
TUnit | TUnit (MTP only) |
Detecting the test platform
The detection logic depends on the .NET SDK version. Run dotnet --version to determine it.
.NET SDK 10+
On .NET 10+, the global.json test.runner setting is the authoritative source:
- If
global.jsoncontains"test": { "runner": "Microsoft.Testing.Platform" }→ MTP - If
global.jsonhas"runner": "VSTest", or notestsection exists → VSTest
Important: On .NET 10+,
<TestingPlatformDotnetTestSupport>alone does not switch to MTP. Theglobal.jsonrunner setting takes precedence. If the runner is VSTest (or unset), the project uses VSTest regardless ofTestingPlatformDotnetTestSupport.
Show full SKILL.md (185 more words)Show less
.NET SDK 8 or 9
On older SDKs, check these signals in priority order:
1. Check the <TestingPlatformDotnetTestSupport> MSBuild property. Look in the .csproj, Directory.Build.props, and Directory.Packages.props. If set to true in any of these files, the project uses MTP.
Critical: Always read
Directory.Build.propsandDirectory.Packages.propsif they exist. MTP properties are frequently set there instead of in the.csproj, so checking only the project file will miss them.
2. Check project-level signals:
| Signal | Platform |
|---|---|
<Sdk Name="MSTest.Sdk"> as project SDK | MTP by default |
<UseMicrosoftTestingPlatformRunner>true</UseMicrosoftTestingPlatformRunner> | MTP runner (xUnit) |
<EnableMSTestRunner>true</EnableMSTestRunner> | MTP runner (MSTest) |
<EnableNUnitRunner>true</EnableNUnitRunner> | MTP runner (NUnit) |
Microsoft.Testing.Platform package referenced directly | MTP |
TUnit package referenced | MTP (TUnit is MTP-only) |
Note: The presence of
Microsoft.NET.Test.Sdkdoes not necessarily mean VSTest. Some frameworks (e.g., MSTest) pull it in transitively for compatibility, even when MTP is enabled. Do not use this package as a signal on its own — always check the MTP signals above first. Key distinction: VSTest is the classic platform that usesvstest.consoleunder the hood. Microsoft.Testing.Platform (MTP) is the newer, faster platform. Both can be invoked viadotnet test, but their filter syntax and CLI options differ.
© microsoft, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file
Files
Just SKILL.md in .agents/skills/platform-detection of microsoft/testfx.
Open the folder on GitHubat commit 44b9dcc
Compare with similar skills
Platform Detection next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.
| Skill | Stars | Used in | Tokens | Auto-check | Licence | Repo updated |
|---|---|---|---|---|---|---|
| Platform Detection this skillmicrosoft/testfx | 1k | — | ~886 | Automated safety check: Pass | MIT | |
| New Event Sourceaws/aws-lambda-dotnet | 1.7k | — | ~3k | Automated safety check: Pass | Apache-2.0 | |
| ScottPlot Test RunnerScottPlot/ScottPlot | 6.8k | — | ~308 | Automated safety check: Pass | MIT | |
| Aspire Integration TestingDevBetterCom/DevBetterWeb | 157 | 2 repos | ~2.3k | Automated safety check: Pass | None | |
| Vstest Build Testmicrosoft/vstest | 969 | — | ~1.9k | Automated safety check: Pass | MIT | |
| Coverage Analysisrunceel/ReactiveProperty | 944 | — | ~5.9k | Automated safety check: Warn | MIT |
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Related
Works with
Categories
Questions about Platform Detection
What does Platform Detection do?
Reference data for detecting the test platform (VSTest vs Microsoft.Testing.Platform) and test framework (MSTest, xUnit, NUnit, TUnit) from project files. Platform Detection is an agent skill from microsoft/testfx, published by the product's own GitHub organization.Platform) and test framework (MSTest, xUnit, NUnit, TUnit) from project files.
When should I use Platform Detection?
Platform Detection fits situations like: tasks that involve Unit testing.
How do I install Platform Detection in Claude Code?
Run `npx skills add microsoft/testfx --skill platform-detection -a claude-code`. Or copy the skill folder (.agents/skills/platform-detection in microsoft/testfx) into .claude/skills/platform-detection in your project. Claude Code loads it when a task matches its description.
How do I install Platform Detection in Codex?
Run `npx skills add microsoft/testfx --skill platform-detection -a codex`. Or copy the skill folder (.agents/skills/platform-detection in microsoft/testfx) into .agents/skills/platform-detection in your project. Codex loads it when a task matches its description.
Can I use Platform Detection in Cursor, Gemini CLI or GitHub Copilot?
Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add microsoft/testfx --skill platform-detection -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/platform-detection, .gemini/skills/platform-detection, .github/skills/platform-detection and .opencode/skills/platform-detection in your project.
What does Platform Detection need to run?
Going by SKILL.md and its folder, Platform Detection needs the command-line tools its instructions call (dotnet).
Does Platform Detection access the network?
SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.
Is Platform Detection safe to install?
Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.
What licence does Platform Detection use?
Platform Detection is published under the MIT licence (declared in SKILL.md). It allows redistribution, so the full SKILL.md is shown on this page.
How many tokens does Platform Detection use?
About 886 tokens (SKILL.md is roughly 3.5k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.
What are the alternatives to Platform Detection?
Skills that share tags, products or a category with Platform Detection: New Event Source (aws/aws-lambda-dotnet, 1.7k stars), ScottPlot Test Runner (ScottPlot/ScottPlot, 6.8k stars), Aspire Integration Testing (DevBetterCom/DevBetterWeb, 157 stars) and Vstest Build Test (microsoft/vstest, 969 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Platform Detection?
microsoft (a GitHub organization, an official publisher) maintains it in microsoft/testfx, which has 1,047 GitHub stars. The repository holds 44 skills in this directory. The repository was last updated on October 7, 2026.
Source: microsoft/testfx on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.