Development Claude Skills
8 676 development skills from 759 authors. They write and change code. Half of them fit into 1 830 tokens or less — that is what one costs your context window when the agent loads it. 1 213 ship runnable scripts rather than instructions alone. 42 of them cannot work without an MCP server, most often rube. We also found 1 172 copies of these same skills sitting in other people's repositories — counted once here, not 1 172 times.
8 676 unique 759 authors 5 250 updated this month 1 369 from vendors
Generate MSBuild binary logs (binlogs) for build diagnostics and analysis. USE FOR: adding /bl:{} to any dotnet build, test, pack, publish, or restore command to capture a full build execution trace, prerequisite for binlog-failure-analysis and build-perf-diagnostics skills, enabling post-build investigation of errors or performance. Requires MSBuild 17.8+ / .NET 8 SDK+ for {} placeholder; PowerShell needs -bl:{{}}. DO NOT USE FOR: non-MSBuild build systems (npm, Maven, CMake), analyzing an existing binlog (use binlog-failure-analysis instead).
> Calculates targeted CRAP (Change Risk Anti-Patterns) scores for a named .NET method, class, or single source file. Use when the user explicitly asks to compute CRAP scores or assess risky untested code for a specific target, combining Cobertura coverage data with cyclomatic complexity analysis. coverage" diagnosis, what's blocking coverage, or where to add tests across a project (use coverage-analysis); writing tests; running tests without CRAP context.
> Scan C# source files for hard-to-test static dependencies — DateTime.Now/UtcNow, File.*, Directory.*, Environment.*, HttpClient, Console.*, Process.*, and other untestable statics. Produces a ranked report of static call sites by frequency. identify hard-to-mock code, find DateTime.Now usage, detect static coupling, testability report, static analysis for testability. migrating code (use migrate-static-to-wrapper), general code review, or finding statics that are already behind abstractions.
Reference data for .NET test framework detection patterns, assertion APIs, skip annotations, setup/teardown methods, and common test smell indicators across MSTest, xUnit, NUnit, and TUnit. Loaded by test analysis skills (test-anti-patterns) as framework-specific lookup tables.
Guide for diagnosing and improving MSBuild project evaluation performance. USE FOR: builds slow before any compilation starts, high evaluation time in binlog analysis, expensive glob patterns walking large directories (node_modules, .git, bin/obj), deep import chains (>20 levels), preprocessed output >10K lines indicating heavy evaluation, property functions with file I/O ($([System.IO.File]::ReadAllText(...))), multiple evaluations per project. Covers the 5 MSBuild evaluation phases, glob optimization via DefaultItemExcludes, import chain analysis with /pp preprocessing. DO NOT USE FOR: compilation-time slowness (use build-perf-diagnostics), incremental build issues (use incremental-build), non-MSBuild build systems.
> Generate wrapper interfaces and DI registration for hard-to-test static dependencies in C#. Produces IFileSystem, IEnvironmentProvider, IConsole, IProcessRunner wrappers, or guides adoption of TimeProvider and IHttpClientFactory. make static testable, make class testable, create abstraction for File.*, generate DI registration, TimeProvider adoption, IHttpClientFactory setup, testability wrapper, mock-friendly interface, mock time in tests, create the right abstraction to mock, how to mock DateTime, test code using File.ReadAllText, what abstraction for Environment, how to make statics injectable, adopt System.IO.Abstractions, make file calls testable. sites (use migrate-static-to-wrapper), general interface design not about testability.
Reference data for test filter syntax across all platform and framework combinations: VSTest --filter expressions, MTP filters for MSTest/NUnit/xUnit v3/TUnit, and VSTest-to-MTP filter translation. DO NOT USE directly — loaded by run-tests, mtp-hot-reload, and migrate-vstest-to-mtp when they need filter syntax.
> Grades a specified set of test methods individually and produces a concise table mapping each test (fully-qualified name) to a letter grade (A–F), a score band, pseudo-mutation resilience, a one-line note, and a concrete improvement for every grade below A — designed to be posted as a PR comment. Use when the caller wants per-test feedback on a curated list of methods (for example, the new or modified tests in a pull request), not a Go, Ruby (RSpec/Minitest), Rust, Swift (XCTest/Swift Testing), Kotlin (JUnit/Kotest), PowerShell (Pester), C++ (GoogleTest/Catch2/doctest). Input is a list of test methods (or method bodies / file+line spans); full suite audits (use test-quality-auditor agent or test-anti-patterns), writing new tests (use code-testing-generator agent or writing-mstest-tests), fixing failures, or measuring code coverage.
> Migrate MSTest v1 or v2 test project to MSTest v3. Use when user says "upgrade MSTest", "upgrade to MSTest v3", "migrate to MSTest v3", "update test framework", "modernize tests", "MSTest v3 migration", "MSTest compatibility", "MSTest v2 to v3", or build errors after updating MSTest packages from 1.x/2.x to 3.x. (Microsoft.VisualStudio.QualityTools.UnitTestFramework) or MSTest v2 NuGet (MSTest.TestFramework 1.x-2.x) to MSTest v3, fixing assertion overload errors (AreEqual/AreNotEqual), updating DataRow constructors, replacing .testsettings with .runsettings, timeout behavior changes, target framework compatibility (.NET 5 dropped -- use .NET 6+; .NET Fx older than 4.6.2 dropped), adopting MSTest.Sdk. First step toward MSTest v4 -- after this, use migrate-mstest-v3-to-v4. migrating between frameworks (MSTest to xUnit/NUnit), or general .NET upgrades unrelated to MSTest.
> Fix build errors and breaking changes after upgrading MSTest from v3 to v4, or plan a complete MSTest v3-to-v4 migration. Use when user says "upgrade to MSTest v4", "MSTest 4 migration", "MSTest v4 breaking changes", "tests don't compile after upgrading MSTest", or has errors CS0507, CS0103, CS1061, CS1615 after updating MSTest packages from 3.x to 4.x. sealed custom attributes, ClassCleanupBehavior removal, TestContext.Properties Contains to ContainsKey, Assert.ThrowsException to ThrowsExactly, Assert.IsInstanceOfType out parameter removal, ExpectedExceptionAttribute removal, TestTimeout enum removal, [TestMethod("name")] to DisplayName syntax, TreatDiscoveryWarningsAsErrors, TestContext.TestName in ClassInitialize, MSTest.Sdk MTP changes, dropped TFMs (net6.0/net7.0 to net8.0+). first), migrating between test frameworks, or general .NET upgrades.
> Migrates .NET test projects from VSTest to Microsoft.Testing.Platform (MTP). Use when user asks to "migrate to MTP", "switch from VSTest", "enable Microsoft.Testing.Platform", "use MTP runner", or mentions EnableMSTestRunner, EnableNUnitRunner, or UseMicrosoftTestingPlatformRunner. discovered, --ignore-exit-code, TESTINGPLATFORM_EXITCODE_IGNORE), conditioning OutputType=Exe to test projects when centralizing MTP properties in Directory.Build.props. Supports MSTest, NUnit, xUnit.net v2 (via YTest.MTP.XUnit2), and xUnit.net v3 (native MTP). Covers runner enablement, CLI argument translation, xUnit.net v3 filter migration (--filter-class, --filter-trait, --filter-query), Directory.Build.props and global.json config, CI/CD pipeline updates, and MTP extension packages. xUnit.net v2 to v3 API migration, MSTest version upgrades, TFM upgrades, or UWP/WinUI test projects.
> Mechanically replace static dependency call sites with wrapper or built-in abstraction calls across a bounded scope (file, project, or namespace). Performs codemod-style bulk replacement of DateTime.UtcNow to TimeProvider.GetUtcNow(), File.ReadAllText to IFileSystem, and similar transformations. Adds constructor injection parameters and updates DI registration. TimeProvider, migrate static calls to wrapper, bulk replace File.* with IFileSystem, codemod static to injectable, add constructor injection for time provider, mechanical migration of statics, refactor DateTime to TimeProvider, swap static for injected dependency, convert static calls to use abstraction, replace statics in a class, migrate one file to TimeProvider, scoped migration, update call sites. wrappers (use generate-testability-wrappers), migrating between test frameworks.
> Microsoft.Testing.Platform) a project uses from `Directory.Build.props`, `global.json`, and `.csproj`, then picks the matching command syntax. USE test runner/platform from project files; `--` separator rules on .NET SDK 8/9 vs 10+; choosing the right filter syntax for MSTest / xUnit / NUnit / TUnit (--filter, --filter-class, --filter-trait, --filter-query, --treenode-filter); TRX/reporting (--report-trx vs --logger trx); blame/hang/crash diagnostics (--blame-hang-timeout, --blame-crash); running tests against a single target framework when a project targets multiple TFMs (e.g., `<TargetFrameworks>net8.0;net9.0</TargetFrameworks>`, `--framework <TFM>`); and avoiding MTP/VSTest argument mixups (--logger trx on MTP, --report-trx on VSTest, --blame on MTP). failing test logic.
Canonical patterns for writing custom MSBuild targets. USE FOR: diagnosing and fixing custom target authoring anti-patterns, reviewing MSBuild target definitions for correctness, diagnosing broken SDK target chains across files (e.g., Directory.Build.targets silently redefining SDK targets), fixing targets that replace CompileDependsOn instead of extending it with $(CompileDependsOn), fixing query targets that return stale results due to Outputs vs Returns misuse, fixing missing Inputs/Outputs causing unnecessary rebuilds, fixing missing FileWrites registration. Covers DependsOnTargets vs BeforeTargets vs AfterTargets, the Build→CoreBuild three-level pattern, hooking into the build pipeline, the $(XxxDependsOn) chain-extension pattern. DO NOT USE FOR: incremental build tuning (use incremental-build), parallelization (use build-parallelism), general anti-patterns (use msbuild-antipatterns), non-MSBuild build systems.
Catalog of MSBuild anti-patterns with detection rules and fix recipes. USE FOR: reviewing, auditing, or cleaning up .csproj, .vbproj, .fsproj, .props, .targets, or .proj files. Each anti-pattern has a symptom, explanation, and concrete BAD→GOOD transformation. Covers Exec-instead-of-built-in-task, unquoted conditions, hardcoded paths, restating SDK defaults, scattered package versions, and more. DO NOT USE FOR: non-MSBuild build systems (npm, Maven, CMake, etc.), project migration to SDK-style (use msbuild-modernization).
> Audits existing test code in any language for anti-patterns and quality issues — produces a severity-ranked report (Critical / Warning / Info) Java (JUnit/TestNG), Go, Ruby (RSpec/Minitest), Rust, Swift, Kotlin (JUnit/Kotest), PowerShell (Pester), C++ (GoogleTest/Catch2). INVOKE when asked to audit, review, rank, or find problems in existing tests — "audit my tests", "test smell audit", "rank by severity", tests that pass but verify nothing, no/missing assertions, swallowed exceptions, always-true / self-comparing / tautological assertions, broad exception types, flakiness (sleep/Date.now/time.sleep), ordering dependency, shared global state, duplicated tests, magic values, missing await on async assertions. writing-mstest-tests for MSTest); running tests (use run-tests); framework migration.
Source-blind user behavior validation against a prewritten contract for apps, CLIs, APIs, and generated artifacts.
| Best practices for Manim Community Edition - the community-maintained Python animation engine. Covers Scene structure, animations, LaTeX/MathTex, 3D with ThreeDScene, camera control, styling, and CLI usage. NOT for ManimGL/3b1b version (which uses `manimlib` imports and `manimgl` CLI).
| Best practices for ManimGL (Grant Sanderson's 3Blue1Brown version) - OpenGL-based animation engine with interactive development. Covers InteractiveScene, Tex with t2c, camera frame control, interactive mode (-se flag), 3D rendering, and checkpoint_paste() workflow. NOT for Manim Community Edition (which uses `manim` imports and `manim` CLI).
> Use when troubleshooting an agent built with the Microsoft Agents SDK (Microsoft.Agents.Hosting.AspNetCore and related packages) in C# / .NET. startup, 401 or auth errors on incoming requests, the bot not responding to messages, appsettings.json configuration problems, Azure AD credential failures (AADSTS errors), port conflicts, or the agent not connecting in Teams or the Agents Playground. Use even if the user doesn't mention the SDK by name — trigger on symptoms like "my bot won't start", "getting 401s", or "bot isn't responding."
Use when migrating a Microsoft 365 Agents SDK agent that uses ActivityHandler or TeamsActivityHandler to AgentApplication. This is ONLY for DotNet projects that uses `Microsoft.Agents.*` packages. Triggered by Agents SDK bots that subclass ActivityHandler or TeamsActivityHandler that need to be modernized to AgentApplication routing.
> Use when any code imports Microsoft.Agents.Hosting.AspNetCore, Microsoft.Agents.Builder, or related Agents SDK packages, or when the user is building, configuring, or asking questions about a Microsoft 365 Agents SDK agent in C# / .NET. Trigger on questions about appsettings.json, connection configuration, AgentApplication patterns, OAuth sign-in flows, storage backends, cards, streaming, or local testing with the Agents Playground — even if no code exists yet and the user is planning or asking how to get started.
> Use when any code imports @microsoft/agents-hosting, @microsoft/agents-hosting-express, or related Agents SDK packages, or when the user is building, configuring, or asking questions about a Microsoft 365 Agents SDK agent in TypeScript. Trigger on questions about environment variables, connection configuration, AgentApplication patterns, OAuth sign-in flows, storage backends, cards, streaming, or local testing with the Agents Playground — even if no code exists yet and the user is planning or asking how to get started.
> Use when provisioning Azure resources for a Microsoft Agents SDK application — including creating an Azure Bot Service resource, setting up Entra app registrations, configuring identity credentials (UserManagedIdentity, FederatedCredentials, or ClientSecret), adding a Teams channel, running Bicep deployments for SSO, or setting up OAuth user sign-in connections via az CLI. Trigger even if the user doesn't say "provision" — use on requests like "set up my bot on Azure", "deploy my bot", "configure Azure for my bot", or "get Teams SSO working." Applies to all languages (dotnet, Node.js, Python).
> Use when troubleshooting an agent built with the Microsoft Agents SDK (@microsoft/agents-hosting and related packages). Trigger on any of these on incoming requests, the bot not responding to messages, .env configuration problems, Azure AD credential failures (AADSTS errors), port conflicts, or the agent not connecting in Teams or the Agents Playground. Use even if the user doesn't mention the SDK by name — trigger on symptoms like "my bot won't start", "getting 401s", or "bot isn't responding."
> Use when migrating a Bot Framework .NET SDK bot to Microsoft 365 Agents SDK. Microsoft.Bot.Builder.Integration.AspNet.Core that want to migrate to Agents SDK.
> Manages stacked PRs and splits multi-part work into reviewable branches with gh-stack. Use for stack creation, viewing, edits, push, submit, sync, rebase, merge, or checkout; when asked to split or isolate work for review; whenever a user mentions a stack, branch layers, dependent PRs, or gh stack; or when a stack is checked out.
Use when user requests diagrams, flowcharts, architecture charts, or visualizations. Also use proactively when explaining systems with 3+ components, complex data flows, or relationships that benefit from visual representation. Generates .excalidraw files and exports to PNG/SVG via Kroki API or locally using excalidraw-brute-export-cli.
Best practices for Remotion - Video creation in React
Generate a lean AGENTS.md hub file for a repository or area, including recommended topics for detail files.
Generate a concise .github/copilot-instructions.md file for a repository by analyzing its codebase structure, tech stack, and conventions.
Generate a concise .instructions.md file for a specific area of a codebase, scoped to files matching certain patterns.
Generate a deep-dive instruction file about a specific topic for a repository or area.
Modify, build, test, debug, and contribute to NVIDIA cuOpt (C++/CUDA, Python, server, CI). Use for solver internals, PRs, DCO, and code conventions.
Install cuOpt for Python, C, or server via pip, conda, or Docker; verify the install. For building cuOpt from source, see cuopt-developer.
cuOpt REST server — start server, endpoints, Python/curl client examples. Use when the user is deploying or calling the REST API.
LP, MILP, and QP (beta) with cuOpt — Python, C, and CLI. Use when the user is solving LP, MILP, or QP with any cuOpt interface.
Vehicle routing (VRP, TSP, PDP) with cuOpt — Python API only. Use when the user is building or solving routing in Python.
Use when working in the Cali repository or when you need to run, extend, or debug the Cali CLI for mobile React Native and Expo workflows. Covers Cali commands (`qa`, `review`, `perf-review`, `dev`), the shared `cali-context.json` contract, local mode selection, required local CLIs, provider setup, and CI integration patterns.
FBOSS coding standards and patterns. Auto-loaded when writing code in fboss/ to catch architecture violations, SAI/SDK misuse, thrift_cow pitfalls, platform config errors, and testing gaps. For explicit multi-reviewer review, use /fboss-review instead.
Debug FBOSS AgentHwTest failures - build, run, analyze logs, crash debug, vendor diag shell, hypothesis-driven debugging. Use when running sai_agent_hw_test or multi_switch_agent_hw_test and investigating test failures.
QDK programming guide for Q#, OpenQASM, and the qsharp/qdk Python API. Use when: writing or editing Q# or OpenQASM code, running quantum programs, resource estimation, circuit generation, noisy simulation, Azure Quantum submission, Qiskit/Cirq/PennyLane interop, or Q# testing and standard library usage.
> Model Kotlin persistence code correctly for Spring Data JPA and Hibernate. Covers entity design, identity and equality, uniqueness constraints, relationships, fetch plans, and common ORM (Object-Relational Mapping) traps specific to Kotlin. Use when creating or reviewing JPA (Java Persistence API) entities, diagnosing N+1 or LazyInitializationException, placing indexes and uniqueness rules, or preventing Kotlin-specific bugs such as data class entities and broken equals/hashCode.
Migrate KMP projects from CocoaPods (kotlin("native.cocoapods")) to Swift Package Manager (swiftPMDependencies DSL) — replaces pod() with swiftPackage(), transforms cocoapods.* imports to swiftPMImport.*, and reconfigures the Xcode project.
> Migrate Kotlin (and Java) code from kotlinx.collections.immutable 0.3.x / 0.4.x to the latest 0.5.x. The 0.5.x line renames every copy-returning method on PersistentList / PersistentMap / PersistentSet / PersistentCollection to a participial form per KEEP-0459 (add→adding, removeAt→removingAt, set→replacingAt, put→putting, clear→cleared, …) and version, recompile, and apply the rename each deprecation warning names. Use when the user mentions kotlinx.collections.immutable 0.5.x, PersistentList migration, "Use adding() instead", KEEP-0459, or sees deprecation warnings from kotlinx.collections.immutable.
> Use when converting Java source files to idiomatic Kotlin, when user mentions "java to kotlin", "j2k", "convert java", "migrate java to kotlin", or when working with .java files that need to become .kt files. Handles framework-aware conversion for Spring, Lombok, Hibernate, Jackson, Micronaut, Quarkus, Dagger/Hilt, RxJava, JUnit, Guice, Retrofit, and Mockito.
> Diagnoses and fixes slow Kotlin/Native compilation and linking in Kotlin Multiplatform projects that target iOS. Use when the user reports slow iOS or shared-framework builds, long linkDebug*/linkRelease* or XCFramework tasks, cold CI builds that re-download the Kotlin/Native toolchain, KSP or other generated code on the native path, transitiveExport usage, or asks for a local-development versus CI build performance plan.
Datadog API CLI with 49 command groups, 300+ subcommands. Skills and domain agents for monitoring, logs, APM, security, and infrastructure.