dotnet

Scaffolds new agent skills for the dotnet/skills repository. Use when creating a new skill, generating SKILL.md files, writing a skill description that the runtime will actually route to, or setting up skill directory structures. Handles frontmatter…

Diagnoses and fixes skills in the dotnet/skills repository that lose to their own baseline, fail to activate, time out, or return "no credible improvement". Use when an evaluation verdict is a regression or underpowered, when a skill regressed after a change,…

Analyze assertion quality, depth, variety, and false confidence in existing tests. ALWAYS USE when asked about weak, shallow, trivial, always-true, self-referential, assertion-free, presence/truthiness-only, or insufficiently diverse assertions, including…

Provides file paths to language-specific extension files for the code-testing pipeline. Read this reference-only catalog for extension guidance files (e.g., dotnet.md for .NET, cpp.md for C++). Agents and skills read its bundled files directly; do not invoke…

ALWAYS USE for test work that requires changes: write, add, generate, repair, or strengthen tests for existing code in xUnit, MSTest, NUnit, pytest, Vitest/Jest, Go, or another framework. Includes regression cases, failing or flaky tests, coverage-driven…

Grade a curated list of individual tests for readiness, A-F quality, and concrete improvements. ALWAYS USE FOR: grade tests, review only a named test, per-test readiness decisions, or quality bands for supplied methods, bodies, file spans, or bounded PR…

ALWAYS USE when asked to migrate, replace, or make testable existing C# static calls with a named wrapper or built-in abstraction: DateTime.UtcNow/Now or DateTimeOffset.UtcNow to TimeProvider/IClock, File.* to IFileSystem or an existing store such as…

Set up or recover MTP hot reload for a long-lived console-host edit/re-run loop in a Microsoft Testing Platform project. Use for explicit MTP console requests such as "enable hot reload", "dotnet run to rerun on edit", or unsupported/rude edits. Covers setup,…

Write and repair C# bindings for Java/Kotlin Android libraries with .NET for Android. USE FOR: direct/full AAR or JAR bindings, AndroidMavenLibrary, Metadata.xml, Additions, missing generated APIs, Kotlin JVM signatures, binding-generator warnings,…

Create Android slim bindings for MAUI/.NET Android. USE FOR: Native Library Interop, thin Kotlin/Java wrapper design, building wrapper AARs with Gradle, Java-friendly callbacks, @JvmStatic, and dependencies of slim wrappers. DO NOT USE FOR: direct/full…

Run DevFlow inspect-and-fix loops for MAUI apps. USE FOR: launch, device selection, agent recovery, broker/port/adb, tree/screenshot, Blazor CDP, and iterative UI debugging. DO NOT USE FOR: first-time setup or non-MAUI automation. INVOKES: DevFlow `maui_*`…

Run DevFlow inspect-and-fix loops for MAUI apps. USE FOR: launch, device selection, agent recovery, broker/port/adb, tree/screenshot, Blazor CDP, and iterative UI debugging. DO NOT USE FOR: first-time setup or non-MAUI automation. INVOKES: DevFlow `maui_*`…

Add MAUI DevFlow to a .NET MAUI project with agent package references, MauiProgram.cs registration, Blazor WebView support, GTK variants, Central Package Management guidance, and verification commands. USE FOR: first-time DevFlow setup, reviewing what files…

Legacy DevFlow debug skill. USE FOR: `maui-ai-debugging`, `maui devflow`, screenshots, visual tree, Blazor CDP, simulator/emulator debugging. DO NOT USE FOR: setup, desktop automation, AppleScript, host `xdotool`.

Add DevFlow to a MAUI app. USE FOR: package refs, `MauiProgram` registration, Blazor WebView/GTK variants, verification after `maui devflow init`. DO NOT USE FOR: troubleshooting, debugging, UI inspection, or build failures. INVOKES: `maui devflow`, `dotnet`.

{what this skill teaches agents}

Validate a Blazor feature or behavior interactively in a browser using the canonical Components samples in this repo, before writing E2E tests. USE FOR exercising a Blazor change in src/Components (a render-mode behavior, an interactive component, enhanced…

Orchestrate an MSBuild release: create the tracking issue, branch, configure DARC channels and subscriptions, bump version in main, final-brand the release branch, insert into VS, and publish post-GA. Covers the full monthly release lifecycle aligned with VS…

Guide for migrating MSBuild tasks to multithreaded mode support, including compatibility red-team review. Use this when converting tasks to thread-safe versions, implementing IMultiThreadableTask, adding TaskEnvironment support, or auditing migrations for…

Investigate source-build failures in dotnet/dotnet VMR CI builds. USE FOR any mention of "prebuilt", "source-build/source-only failure", "source-build-assets (SBRP)", "poison", source-build repo build ordering problems, binary detection/removal, or any build…

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Drive the .NET SDK breaking-change documentation-and-notification process for a NuGet change that has already been implemented. Invoke this once a NuGet/Home issue (or its implementing NuGet.Client PR) is labeled `Breaking-Change`. It makes sure the correct…

Cherry-pick (backport/forward-port) one or more commits from one branch onto another, creating a fresh branch and opening a pull request that follows the repository's conventions. Use this whenever the user wants to move, port, backport, or cherry-pick a…

Create or update a pull request using the NuGet.Client PR template. Use when asked to: create PR, open PR, push and create PR, submit PR, open pull request, send changes for review, update PR description, fix PR body, edit PR description, update the PR.

Analyze dotnet/maui PR failures across maui-pr, maui-pr-devicetests, and maui-pr-uitests against the latest five completed runs on the PR's target branch. Report only whether failures are PR-related, with failure links grouped by pipeline. When no current…

Full manual-label policy for the maintainer-only /issue triage command in dotnet/maui. Assess issue type, area, platform, status, regression, priority, performance, ownership, versions, workarounds and planning against existing evidence. Do not use for the…

Trace a reported dotnet/maui issue to the commit or PR that introduced its regression using release boundaries, source history, and linked evidence. Use for "/issue trace-regression", "which PR introduced this issue", or "trace this regression". Distinguish…

Queries and triages open GitHub issues that need attention. Helps identify issues needing milestones, labels, or investigation.

Interpret pinned managed benchmark evidence for the /review performance GitHub Agentic Workflow. Produce a narrative for independently validated reporting; never execute measurements or publish directly.

Investigate CI failures for dotnet/maui PRs and the nightly/official signed build — build errors, Helix test logs, and binlog analysis. Use when asked about failing checks, CI status, test failures, 'why is CI red', 'build failed', 'what's failing on PR', 'is…

Labels issues and pull requests in the dotnet/maui repository with `area-*` and `platform/*` labels ONLY, based on technical content and platform-file conventions. Used by the gh-aw agentic-labeler workflow and available for batch evaluation and interactive…

Analyzes your local Copilot CLI sessions for dotnet/maui to drive iterative improvements to the PR-review agent (and other agents, skills, and instruction files). Runs a select → extract → score → judge → cluster → propose → emit-eval loop: a deterministic…

Guidance for writing and reviewing SIMD / hardware-intrinsics code in dotnet/runtime. USE FOR: vectorizing a scalar algorithm, writing or reviewing code that uses Vector128/Vector256/Vector512, the generic Vector type, or the platform intrinsics in…

Create prototype-backed API proposals for dotnet/runtime. Use when asked to draft an API proposal, write an api-suggestion issue, refine a vague API idea into a complete proposal, or improve a proposal marked api-needs-work. Covers the full pipeline from…

Run the TechEmpower ASP.NET Core benchmarks against a locally-built dotnet/runtime, either locally with an SDK overlay or on external infrastructure using Crank, to validate the end-to-end impact of a runtime change (e.g. sockets, io_uring, GC, JIT) under…

Generate breaking change documentation for merged dotnet/runtime PRs. USE FOR: creating breaking change docs, "document this breaking change", "write breaking change issue for PR #NNNNN", processing PRs labeled needs-breaking-change-doc-created. DO NOT USE…

Build and test dotnet/runtime locally. Covers the mandatory baseline build, per-component build and test commands, Windows/PowerShell equivalents, running individual tests, and troubleshooting. USE FOR: any build or test invocation in this repo, and before…

Analyze a concrete CI failure and draft a Known Build Error issue or update in dotnet/runtime. Publish only with explicit user authorization or scoped authorization from an executing workflow's documented publication contract. Use when a failure is…

Triage a dotnet/runtime GitHub issue with duplicate search, label check, reproduction, and ecosystem research, then recommend KEEP/CLOSE/NEEDS INFO. Use when asked to triage, evaluate, assess, or check a specific GitHub issue. Also use when asked "is this a…

Extract a standalone JIT regression test case from a given GitHub issue and save it under a JIT regression runner folder. USE FOR: creating JIT regression tests, extracting repro code from dotnet/runtime issues, "write a test for this JIT bug", "create a…

Orchestrate an MSBuild release: create the tracking issue, branch, configure DARC channels and subscriptions, bump version in main, final-brand the release branch, insert into VS, and publish post-GA. Covers the full monthly release lifecycle aligned with VS…

Guides changes to MSBuild binary log infrastructure. Consult when modifying BinaryLogger or BinaryLogReplayEventSource, adding new BuildEventArgs types, changing event serialization/deserialization, modifying ProjectImportsCollector, adjusting message…

Deploy locally-built MSBuild binaries into a Visual Studio installation for testing and debugging. Use when you need VS itself to use your local MSBuild changes, or when debugging MSBuild as invoked by VS.

Guide for migrating MSBuild tasks to multithreaded mode support, including compatibility red-team review. Use this when converting tasks to thread-safe versions, implementing IMultiThreadableTask, adding TaskEnvironment support, or auditing migrations for…

Guide for running MSBuild unit tests efficiently. Use when running, scoping, filtering, or speeding up unit tests in this repository, or when finalizing a change with a heavier validation pass. Covers xUnit v3 + Microsoft.Testing.Platform (MTP) specifics and…

Review and merge open bot PRs: dependency updates from dotnet-maestro, codeflow from dotnet/dotnet, and OneLoc localization PRs. Produces a clickable dashboard with CI status, review state, and suspicious file flags. Use when you want to triage all open bot…

Guides struct-based COM interop in MSBuild using CsWin32 patterns. Consult when working with ComScope<T>, ComClassFactory, IComIID, IID.Get<T>(), delegate* unmanaged vtables, CoCreateInstance, or manually defining COM interfaces not in Win32 metadata (e.g.…

Guides CsWin32 P/Invoke interop in MSBuild. Consult when working with the PInvoke class, Windows.Win32 namespaces, FEATURE_WINDOWSINTEROP, HANDLE/HMODULE/HRESULT types, BufferScope<T>, replacing [DllImport] with CsWin32, or conditioning Windows-only code for…

Generate and maintain .NET release notes from `features.json`. Uses `generate-changes` for authoritative shipped-change data, `generate-features` for scoring/triage, `update-existing-branch` for incremental reruns on populated branches, `editorial-scoring`…

Refresh an existing .NET release-notes milestone branch set incrementally. Checks whether the VMR ref moved, regenerates `changes.json` only when needed, merges the delta into `features.json`, integrates new material into existing markdown clusters across the…

Generate `features.json` from `changes.json` by ranking and annotating shipped changes. `features.json` keeps the same schema as `changes.json` and adds optional scoring fields so release notes, docs, and blog posts can apply different cutoffs. Uses the…

Review `features.json` scores and draft release notes against the editorial examples and the shared `editorial-scoring` rubric. Use it to identify over-scored, under-scored, or missing features before publishing release notes. DO NOT USE FOR: generating…

Validate every release-note feature and its code snippets against the milestone build, and identify preview-to-preview migration steps when updating maintained samples. Reads the exact SDK version from build-metadata.json and installs it in a scoped location…

Validate that a generated API diff matches the APIs actually shipped in a .NET build, and that every new API traces to a real change. Uses dotnet-inspect to query the build's ref packs and cross-references new APIs against candidate PRs to catch missed…

Generate `changes.json` for a .NET release milestone by selecting the correct VMR base/head refs and running `release-notes generate changes`. Handles preview-only multi-branch targeting (`main` vs release branches vs tags) and emits the authoritative…

Route gh-aw workflow design/create/debug/upgrade requests to the right prompts.

Implementation details for EF Core change tracking. Use when changing InternalEntityEntry, ChangeDetector, SnapshotFactoryFactory, or related entity state, snapshot, or property accessor code.

Review EF Core pull requests or local changes for concrete correctness, compatibility, performance, security, and test-coverage problems. Use when asked to review, critique, or check code changes before merge or submission.

Create custom GitHub Copilot agents. Use when asked to create, scaffold, or configure a custom agent, declarative agent, or @-invokable chat participant for GitHub Copilot.

Create GitHub Actions workflows for CI, automation, or PR management. Use when asked to create, scaffold, or add a GitHub Actions workflow (.yml file under .github/workflows/).

Create, review, or fix Agent Skills for GitHub Copilot. Use when asked to create, scaffold, improve, or repair a SKILL.md and its paired harness evaluation.

Implementation details for EF Core migrations. Use when changing MigrationsSqlGenerator, model diffing, migration operations, HistoryRepository, the Migrator or related classes.

Implementation details for EF Core model building. Use when changing ConventionSet, ModelBuilder, IConvention implementations, ModelRuntimeInitializer, RuntimeModel, or related classes.

Implementation details for EF Core scaffolding (reverse engineering). Use when changing ef dbcontext scaffold pipeline implementation, database schema reading, CSharpModelGenerator, or related classes.

Write release notes for completed changes. Use when PR modifies tracked paths and needs release notes entry.

Use when reviewing a PR where duplicated mechanisms, misplaced responsibilities, or competing fixes suggest a substantial design alternative rather than local corrections. Not for isolated bugs, style preferences, or size alone.

Use when about to defer useful work — when you catch yourself writing "follow-up", "future work", "out of scope", "v2", "next phase", "tracked in #NNN", "left as a TODO", "known limitation", or proposing to file an issue instead of finishing. Forces a binary…

Use when a code/test/comment diff is called bloated, slop, LLM slop, bullshit, WTF, crap, rubbish, embarrassing, overengineered, adhoc, or "not paid by LOC"; or when symptoms include bloated comments, superfluous planning .md / .tools / one-time setup /…

Investigate compiler failures, test errors, or unexpected behavior through systematic minimal reproduction, 3-hypothesis testing, and verification. Always re-run builds and tests after changes.

Write a postmortem for a regression that escaped to production, broke real users, and traces back to a design flaw worth documenting for future implementors. Only invoke after confirming no existing postmortem or doc covers the same root cause.

Always invoke after editing `.fs` files under `src/Compiler/`. Fast parse/typecheck without `dotnet build`, plus symbol references and inferred type hints. Use whenever the user asks about F# errors, compile errors, type inference, finding usages, or renaming…

Use when drafting, proposing, creating, or editing prose for a dotnet/fsharp GitHub PR or issue — body, title, comment, review summary, edits — including bare asks like "open a PR", "ship this", "write up what I did", "summarise the change", "reply on the…

Select and run .NET SDK tests through the repository's diagnostic-preserving test entry point. REQUIRED whenever an agent will select, run, or rerun local dotnet/sdk tests, including a project, class, method, targeted test, focused test, smallest relevant…

Migrate .NET test projects from xUnit.net (v2 or v3) to MSTest v4. USE FOR: convert/migrate xUnit tests to MSTest, replace xunit/xunit.v3 packages, port [Fact]/[Theory]/[InlineData]/[MemberData]/[ClassData] to [TestMethod]/[DataRow]/[DynamicData], port…

Review code changes in dotnet/sdk for problems — either a GitHub pull request or local changes in your branch before a PR exists. Use when asked to review a PR, review local or uncommitted changes, do a code review, check a PR or branch for issues, or review…

Keep dotnet/sdk contributor guidance and agent memory synchronized after code changes. Run at the end of tasks that modify code, move files, change public contracts, alter tests or workflows, establish conventions, or reveal durable repository gotchas.

Add, enable, or review a dotnet CLI command or feature in the Native AOT CLI (src/Cli/dotnet-aot) and prove its compatibility. USE FOR: migrating a command or option to AOT, reviewing an AOT migration PR, defining conservative eligibility and managed…

Add, port, or change a .NET code analysis rule (CA####) under src/Microsoft.CodeAnalysis.NetAnalyzers. USE FOR: implementing a new CA analyzer and its code fixer, porting a rule or PR from the retired dotnet/roslyn-analyzers repo, allocating a diagnostic ID…

Run dotnet.Tests incrementally without a full build.cmd rebuild. Use after modifying source code in SDK projects to quickly build only changed projects, deploy their outputs into the redist SDK layout, and run tests against them.

Add or change a dotnet CLI command, subcommand, or option across the relevant CLI projects. USE FOR: adding or changing a dotnet CLI command/subcommand, adding a new Option<T> or Argument<T>, registering a subcommand in the command tree, changing an option's…

Investigate .NET CI failures using the hlx CLI tool via bash. USE FOR: checking Helix job status, searching build logs, downloading test results, AzDO build timeline analysis — when MCP tools aren't loaded or when scripting with JSON output and jq. This is…

Investigate AzDO pipeline failures beyond Helix — build errors, infra tooling crashes, validation test flakiness, artifact cascade failures. USE FOR: "why did the unified-build fail", "what's breaking the pipeline", "how often does this failure occur", "drill…

Analyze CI build and test status from Azure DevOps and Helix for dotnet repository PRs. Use when checking CI status, investigating failures, determining if a PR is ready to merge, or given URLs containing dev.azure.com or helix.dot.net. Also use when asked…

Build the Arcade SDK from source, configure a local NuGet feed with the artifacts, and validate the build by running a test repository against the locally-built packages. Use when testing local Arcade changes against a consuming repo, validating Arcade SDK…

Analyze a failed Azure DevOps PR build by reusing the binlog that build already produced — instead of rebuilding locally. Use when an `azure-pipelines` check on a GitHub PR transitions to `failure` and you need a structured root-cause analysis posted back as…

Analyze VMR codeflow health using maestro MCP tools and GitHub MCP tools. USE FOR: investigating stale codeflow PRs, checking if fixes have flowed through the VMR pipeline, debugging dependency update issues, checking overall flow status for a repo,…

Trace dependency flow across .NET repos through the VMR pipeline. USE FOR: checking if a PR/commit from repo A has reached repo B, finding what runtime SHA is in an SDK build, tracing dependency versions through the VMR, checking if a commit is included in an…

Query Maestro/BAR dependency flow data using the mstro CLI tool via bash. USE FOR: subscription health checks, build flow tracing, codeflow status, channel discovery, triggering subscription updates — when MCP tools aren't loaded or when scripting with JSON…

Perform a branch snap (release branch cut) for dotnet repos like dotnet/roslyn. Use when: snapping a branch, cutting a release branch, creating a release branch, merging main into release, updating VS insertion config, updating darc subscriptions for a snap,…

Investigate Visual Studio integration test failures from Azure DevOps builds. Use when investigating integration test timeouts, crashes, or failures in the roslyn-integration-CI pipeline. Also use when asked "why are integration tests failing", "integration…

Review code changes in dotnet/roslyn for correctness, performance, and consistency with project conventions. Use when reviewing PRs or code changes.

Update the agent knowledge base after making code changes in the Roslyn repo. Run at the end of every task that modifies code, adds files, changes public APIs or diagnostics, or establishes new patterns. Keeps .github/memory/ fresh and reliable.

Set up tracking for a new C# compiler feature: create test plan issue, feature label, update Language Feature Status page, and link related PRs. Use when: setting up a new language feature, creating a test plan, tracking a new csharplang proposal in roslyn,…

Create a merge branch from a chosen base, merge a chosen source/upstream branch into it, resolve common Roslyn conflicts (`.xlf`, `.resx`, compiler codegen), and summarize the resolutions.

Configure a dotnet repository branch to publish build artifacts through a Maestro channel. Use when: publishing branch artifacts to General Testing or another NuGet feed, adding a Darc default channel, enabling official builds for a branch, or setting up…

Install and validate a .NET SDK from an Azure DevOps internal build. Use this when asked to install, validate, or set up a .NET SDK from a dnceng/internal Azure DevOps build link or build ID.