Official agent skill

Msbuild Server

Guide for using MSBuild Server to improve CLI build performance.

OfficialMITAuto-check passedBackend & APIs

Install Msbuild Server

skills CLI

$ npx skills add microsoft/testfx --skill msbuild-server -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI

$ gh skill install microsoft/testfx msbuild-server --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy

$ git clone --depth 1 https://github.com/microsoft/testfx.git skills-src && mkdir -p .claude/skills && cp -r skills-src/.agents/skills/msbuild-server .claude/skills/msbuild-server && rm -rf skills-src

Use ~/.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/

Paste into Claude Code

Install the "msbuild-server" agent skill from https://github.com/microsoft/testfx/tree/main/.agents/skills/msbuild-server into .claude/skills/msbuild-server/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "msbuild-server", 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

$skill-installer install https://github.com/microsoft/testfx/tree/main/.agents/skills/msbuild-server

Type 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.

skills CLI

$ npx skills add microsoft/testfx --skill msbuild-server -a codex

Project install goes to .agents/skills/; add -g for ~/.codex/skills/.

GitHub CLI

$ gh skill install microsoft/testfx msbuild-server --agent codex

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/microsoft/testfx.git skills-src && mkdir -p .agents/skills && cp -r skills-src/.agents/skills/msbuild-server .agents/skills/msbuild-server && rm -rf skills-src

Use ~/.agents/skills/ instead of .agents/skills for a personal install.

Codex skills documentation · loads skills from .agents/skills/

Paste into Codex

Install the "msbuild-server" agent skill from https://github.com/microsoft/testfx/tree/main/.agents/skills/msbuild-server into .agents/skills/msbuild-server/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "msbuild-server", 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.

skills CLI

$ npx skills add microsoft/testfx --skill msbuild-server -a cursor

Project install goes to .agents/skills/; add -g for ~/.cursor/skills/.

GitHub CLI

$ gh skill install microsoft/testfx msbuild-server --agent cursor

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/microsoft/testfx.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/.agents/skills/msbuild-server .cursor/skills/msbuild-server && rm -rf skills-src

Use ~/.cursor/skills/ instead of .cursor/skills for a personal install.

Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/

Paste into Cursor

Install the "msbuild-server" agent skill from https://github.com/microsoft/testfx/tree/main/.agents/skills/msbuild-server into .cursor/skills/msbuild-server/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "msbuild-server", 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

$ gemini skills install https://github.com/microsoft/testfx.git --path .agents/skills/msbuild-server

--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.

skills CLI

$ npx skills add microsoft/testfx --skill msbuild-server -a gemini-cli

Project install goes to .agents/skills/; add -g for ~/.gemini/skills/.

GitHub CLI

$ gh skill install microsoft/testfx msbuild-server --agent gemini-cli

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/microsoft/testfx.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/.agents/skills/msbuild-server .gemini/skills/msbuild-server && rm -rf skills-src

Use ~/.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/

Paste into Gemini CLI

Install the "msbuild-server" agent skill from https://github.com/microsoft/testfx/tree/main/.agents/skills/msbuild-server into .gemini/skills/msbuild-server/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "msbuild-server", 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.

GitHub CLI

$ gh skill install microsoft/testfx msbuild-server

Installs 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).

skills CLI

$ npx skills add microsoft/testfx --skill msbuild-server -a github-copilot

Project install goes to .agents/skills/; add -g for ~/.copilot/skills/.

Manual copy

$ git clone --depth 1 https://github.com/microsoft/testfx.git skills-src && mkdir -p .github/skills && cp -r skills-src/.agents/skills/msbuild-server .github/skills/msbuild-server && rm -rf skills-src

Use ~/.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/

Paste into GitHub Copilot

Install the "msbuild-server" agent skill from https://github.com/microsoft/testfx/tree/main/.agents/skills/msbuild-server into .github/skills/msbuild-server/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "msbuild-server", 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.

skills CLI

$ npx skills add microsoft/testfx --skill msbuild-server -a opencode

OpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.

GitHub CLI

$ gh skill install microsoft/testfx msbuild-server --agent opencode

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/microsoft/testfx.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/.agents/skills/msbuild-server .opencode/skills/msbuild-server && rm -rf skills-src

Use ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.

OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/

Paste into OpenCode

Install the "msbuild-server" agent skill from https://github.com/microsoft/testfx/tree/main/.agents/skills/msbuild-server into .opencode/skills/msbuild-server/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "msbuild-server", 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: msbuild-server
GitHub stars: 1k
Token cost: ~678 tokens
SKILL.md length: 291 words
Files: 1
Skills in repo: 44
Repo updated: Oct 7, 2026
First seen: Oct 7, 2026
Licence: MIT

At a glance

Guide for using MSBuild Server to improve CLI build performance.

Works in 3 steps: Confirm CLI context → Set the environment variable → Validate improvement
Tasks that involve Secrets management
SKILL.md covers When to Use, When Not to Use, Inputs and Workflow, plus 2 more sections
Calls dotnet

What it does

Msbuild Server is an agent skill from microsoft/testfx, published by the product's own GitHub organization. Guide for using MSBuild Server to improve CLI build performance. Activate when developers report slow incremental builds from the command line, or when CLI builds are noticeably slower than IDE builds. Covers MSBUILDUSESERVER=1 environment variable for persistent server-based caching. Do not activate for IDE-based builds (Visual Studio already uses a long-lived process).

Its SKILL.md is about 680 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 Backend & APIs, covering Secrets management and Caching. 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 Secrets management
Tasks that involve Caching

Example prompts

“/msbuild-server”

Workflow steps

3 steps, taken from the step headings in SKILL.md.

Confirm CLI context
Set the environment variable
Validate improvement

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

Msbuild Server loads about 678 tokens when it runs. Until then it costs about 97 tokens; SKILL.md has 291 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it: ~97
When it runs · the whole SKILL.md, loaded when a task matches: ~678

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). 291 words, ~678 tokens.

Download SKILL.mdSave it as .claude/skills/msbuild-server/SKILL.md (or your agent's skills folder).

name: msbuild-server
description: Guide for using MSBuild Server to improve CLI build performance. Activate when developers report slow incremental builds from the command line, or when CLI builds are noticeably slower than IDE builds. Covers MSBUILDUSESERVER=1 environment variable for persistent server-based caching. Do not activate for IDE-based builds (Visual Studio already uses a long-lived process).
license: MIT

MSBuild Server for CLI Caching

Use the MSBuild Server to cache evaluation results across CLI builds, matching the performance advantage Visual Studio gets from its long-lived MSBuild process.

When to Use

Small incremental builds from CLI (dotnet build) are slower than expected
Developers notice that VS builds are faster than CLI builds for the same project
CI agents run many sequential builds of the same repo

When Not to Use

IDE-based builds (Visual Studio already uses a long-lived MSBuild process)
One-off builds where cold-start overhead is acceptable
Build correctness issues are suspected (disable the server to isolate the problem)

Inputs

Input	Required	Description
Shell context	No	The shell where the environment variable will be set (bash, PowerShell, or Windows persistent)

Workflow

Step 1: Confirm CLI context

Verify the developer is building from the command line (dotnet build), not from Visual Studio or another IDE. The MSBuild Server provides no benefit inside an IDE.

Step 2: Set the environment variable

bash

# Bash / CI
export MSBUILDUSESERVER=1

# PowerShell
$env:MSBUILDUSESERVER = "1"

# Windows (persistent)
setx MSBUILDUSESERVER 1

Step 3: Validate improvement

Run two sequential builds of the same project and compare times:

First build (cold): dotnet build -- server starts, no cache benefit
Second build (warm): dotnet build -- should be noticeably faster

The most noticeable improvement is in repos with many projects or complex Directory.Build.props chains.

Validation

MSBUILDUSESERVER=1 is set in the shell
Second sequential build is faster than the first
dotnet build-server shutdown followed by a rebuild confirms the server restarts cleanly

Common Pitfalls

Pitfall	Solution
Expecting improvement in Visual Studio	VS already uses long-lived MSBuild nodes; the server adds no benefit
Build correctness issues after enabling	Run `dotnet build-server shutdown` to reset; if issues persist, disable the server
Server process using unexpected memory	The server persists in background; shut down with `dotnet build-server shutdown` when idle

Files

Just SKILL.md in .agents/skills/msbuild-server of microsoft/testfx.

Open the folder on GitHubat commit 44b9dcc

Compare with similar skills

Msbuild Server 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.

Msbuild Server compared with similar skills
Skill	Stars	Used in	Tokens	Auto-check	Licence	Repo updated
Msbuild Server this skillmicrosoft/testfx	1k	—	~678	Automated safety check: Pass	MIT	today
Project Setupcodewithmukesh/dotnet-claude-kit	751	—	~1.2k	Automated safety check: Pass	MIT	2 mo ago
Rds Sqlserveraws/agent-toolkit-for-aws	2.8k	—	~6.3k	Automated safety check: Pass	Apache-2.0	today
FoundatioFoundatioFx/Foundatio	2.1k	—	~3.9k	Automated safety check: Pass	Apache-2.0	today
Cachingcodewithmukesh/dotnet-claude-kit	751	1 repos	~1.4k	Automated safety check: Pass	MIT	2 mo ago
Dotnet Backend Patternswshobson/agents	40k	7 repos	~6.6k	Automated safety check: Pass	MIT	2 days ago

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Questions about Msbuild Server

What does Msbuild Server do?

Guide for using MSBuild Server to improve CLI build performance. Msbuild Server is an agent skill from microsoft/testfx, published by the product's own GitHub organization. Guide for using MSBuild Server to improve CLI build performance.

When should I use Msbuild Server?

Msbuild Server fits situations like: tasks that involve Secrets management; tasks that involve Caching.

How do I install Msbuild Server in Claude Code?

Run `npx skills add microsoft/testfx --skill msbuild-server -a claude-code`. Or copy the skill folder (.agents/skills/msbuild-server in microsoft/testfx) into .claude/skills/msbuild-server in your project. Claude Code loads it when a task matches its description.

How do I install Msbuild Server in Codex?

Run `npx skills add microsoft/testfx --skill msbuild-server -a codex`. Or copy the skill folder (.agents/skills/msbuild-server in microsoft/testfx) into .agents/skills/msbuild-server in your project. Codex loads it when a task matches its description.

Can I use Msbuild Server 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 msbuild-server -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/msbuild-server, .gemini/skills/msbuild-server, .github/skills/msbuild-server and .opencode/skills/msbuild-server in your project.

What does Msbuild Server need to run?

Going by SKILL.md and its folder, Msbuild Server needs the command-line tools its instructions call (dotnet).

Does Msbuild Server 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 Msbuild Server 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 Msbuild Server use?

Msbuild Server 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 Msbuild Server use?

About 678 tokens (SKILL.md is roughly 2.7k 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 Msbuild Server?

Skills that share tags, products or a category with Msbuild Server: Project Setup (codewithmukesh/dotnet-claude-kit, 751 stars), Rds Sqlserver (aws/agent-toolkit-for-aws, 2.8k stars), Foundatio (FoundatioFx/Foundatio, 2.1k stars) and Caching (codewithmukesh/dotnet-claude-kit, 751 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Msbuild Server?

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.

Install Msbuild Server

Facts

At a glance

What it does

When your agent uses it

Example prompts

Workflow steps

What it can do on your machine

Tool permissions

Runs code

Network

Credentials

Context cost

Safety

SKILL.md

MSBuild Server for CLI Caching

When to Use

When Not to Use

Inputs

Workflow

Step 1: Confirm CLI context

Step 2: Set the environment variable

Step 3: Validate improvement

Validation

Common Pitfalls

Files

Compare with similar skills

Similar skills

More from microsoft/testfx

Related

Questions about Msbuild Server