Skills
98,639 packaged capabilities and playbooks for agents. Install any of them with one command.
Development
Build JSON-defined TanStack Start applications with @json-render/tanstack-start. Use for Start route specs, splat routing, SSR loaders, head metadata, layouts, and client navigation. Do not use for generic TanStack Router apps that do not use json-render.
Test-Driven Repair — given a failing test, spawn a bounded headless `claude -p` (Read/Edit/Bash only) that makes the test pass without modifying it. Modeled on agent-harness-generator's ADR-175 Test-Driven Repair mode. Bounded cost via --max-budget-usd, bounded capability via --allowedTools. Closes the loop the TDD plugins didn't — we generate tests, this fixes the code to satisfy them.
Set up a SendGrid account for email delivery. Covers API key creation (SG.-prefix), domain authentication (DKIM/SPF via CNAME records), Single Sender Verification for testing, SDK installation, and the relationship between SendGrid and Twilio credentials. Use before any other SendGrid skill. This skill is for SendGrid only — not the Twilio Email API (comms.twilio.com).
Diagnostic and advisory skill for email deliverability problems. Use when a developer asks why emails are going to spam, not reaching the inbox, getting blocked, bouncing, or how to improve sender reputation — with or without a specified platform. Covers SendGrid-specific tooling: SPF, DKIM, DMARC, BIMI, IP warmup, list hygiene, bounce/spam rate thresholds, and Engagement Quality Score (SEQ). Do NOT use for Twilio Email (comms.twilio.com / Account SID + Auth Token) — use twilio-email-deliverability-advisor instead. Do NOT use for general email sending questions — use twilio-sendgrid-email-send (SendGrid) or twilio-email-deliverability-advisor instead.
Build and run workflow for WinUI 3 apps with WinApp CLI 0.7+ — project creation with winapp new, per-app NuGet analyzer setup, project-mode winapp run, Native AOT publish runs, crash diagnosis, and prerequisites. Use when creating, building, running, or fixing build errors in a WinUI 3 project
Use when you need to add or review Mongock MongoDB data migrations in a Micronaut application — including Mongock runner/driver selection, Micronaut bean wiring, migration scan packages, @ChangeUnit classes, lock/transaction settings, and Testcontainers verification. This should trigger for requests such as Add Mongock migrations in Micronaut; Review Micronaut MongoDB data migrations; Configure Mongock change units with Micronaut Data MongoDB; Create Mongock change units for Micronaut MongoDB; Review Mongock migration ordering in a Micronaut service. Part of Plinth Toolkit
Use when reviewing, designing, or modifying Java enterprise systems that may support EU Digital Markets Act gatekeeper-platform concerns, core platform services, interoperability, business-user data access, consent-dependent data combination, ranking, self-preferencing, advertising transparency, or anti-circumvention controls. This should trigger for requests such as Review a Java platform for DMA controls; Design interoperability and business-user data access evidence; Add ranking, consent, preference, or anti-circumvention audit controls; Assess gatekeeper-platform engineering evidence before production release. Part of Plinth Toolkit
Write Blender 5.2 add-ons as extensions — blender_manifest.toml, operators/panels/menus/property groups/preferences, bpy.props rules after 5.0, undo/redo, modal and timer patterns, GPU drawing (no bgl), bundling Python wheels, CLI validation/build/install, headless testing, and extensions platform publishing. Use when creating or fixing a Blender add-on, tool, or UI
Migrates carousels from Embla, Swiper, Splide, Slick (including react-slick), Flickity, or similar libraries to Blossom Carousel by mapping wrappers, options, methods, events, and plugins to native scrolling, CSS scroll snap, and Blossom's controls and APIs. Use when the user wants to replace, remove, or move off one of these carousel libraries, or compares them with Blossom Carousel.
Structured design dialogue before CloudCannon work that has more than one sensible answer—such as a migration’s editability tradeoffs, modeling a collection or page builder, restructuring content or config, or an ambiguous “make this work with CloudCannon.” Explores intent and constraints, then presents a design for approval before implementation. Not for single well-defined tasks, clear bug fixes, or a detailed spec.
Помогает совместно прояснить задачу, проверить идею, найти корневую причину проблемы или выбрать подход без реализации. Используй, когда пользователь просит обсудить задачу, разобраться в проблеме, сравнить варианты или задаёт вопросы «что думаешь?» и «как лучше сделать?». Не используй, когда пользователь явно просит составить план, реализовать задачу, проверить изменения кода или сохранить знания проекта.
Select and apply numerical differentiation schemes for PDE and ODE discretization — generate finite-difference stencils at arbitrary order and accuracy, choose between central, upwind, compact (Pade), and spectral methods, handle boundary stencils, and estimate truncation error scaling. Use when discretizing spatial derivatives, picking a scheme for advection- or diffusion-dominated problems, building custom stencils for nonstandard operators, or comparing dispersion and dissipation properties of candidate schemes, even if the user just says "how do I approximate this derivative" or "my solution is too diffusive."
Use when executing an engineering plan produced by gitnexus-plan (or a small, bounded task directly): implement step by step with GitNexus impact checks before every symbol edit, run tests from the plan’s scenarios, and gate every commit with detect_changes. Examples: “/gitnexus-work docs/plans/2026-07-11-gitnexus-plan-ingestion-retry.md”, “/gitnexus-work” (latest plan), “execute the plan”
Designs and audits macOS launchd watchdogs: LaunchAgent/LaunchDaemon setup, plist edits, scheduled self-healing, repeated notifications, apps reopening after quit, crash/repair loops, Script Editor alerts, stop/disable/restart, cooldown/backoff, notification throttling, alert decisions, schedule readback, WatchPaths/FSEvents event triggers. Supports periodic observers. launchd daemons, persistent tasks, startup launch, background monitoring, scheduled self-healing, notification-source troubleshooting, event-driven monitoring.
Generates Remotion composition structure focusing ONLY on Sequence ordering, scene transitions, and duration mapping. Input is scene list with durations. Output is COMPOSITION_STRUCTURE.md with Sequence layout and timing calculations. Use when organizing scenes or when asked to "structure composition", "layout scenes", "calculate timing".
Process large codebases (>100 files) using the Recursive Language Model pattern. Orchestrates parallel sub-agents to map-reduce across files without context rot. Use when: analyzing large repositories; auditing security or auth across many files; finding patterns across 50+ files; processing large log files or data dumps.
Use for Roblox Engine API lookup during implementation: finding the correct engine class or service, confirming properties, methods, events, callbacks, datatypes, enums, globals, and built-in libraries, and verifying parameter, return, and property usage for a known engine task. Prefer this skill when the problem is referential rather than architectural.
Use when making or fixing Roblox visual effects or game audio: ParticleEmitter, Beam, Trail, flipbook sprite sheets, slash, hit, impact, explosion, fireball, aura or projectile VFX; effects only one player sees, effects that lag or pile up, particles invisible, popping or too bright; the Audio API (AudioPlayer, Wire, AudioEmitter, AudioListener, AudioDeviceOutput, effects), "no sound", "3D sound not working", music, ducking, footsteps, SoundGroup volumes; or importing Scenario-generated sound effects, music, voice or VFX sheets into a Roblox game.
Use this skill when the user asks about “Server Actions,” “form handling in Next.js,” “mutations,” “useFormState,” “useFormStatus,” “revalidatePath,” or “revalidateTag,” or needs guidance on data mutations and form submissions in Next.js App Router
SwiftUI framework skills — data flow (identity, Observation, state ownership), layout & containers (Layout protocol, lazy-stack performance), AlarmKit, 3D charts, rich text editing, customizable toolbars, and WebKit embedding. Use for SwiftUI state/rendering bugs, custom layouts, scroll performance, or these feature areas.
Use when you need to add or review Mongock MongoDB data migrations in a Quarkus application — including the Quarkiverse Mongock extension, Quarkus MongoDB client configuration, migrate-at-start, @ChangeUnit classes, lock/transaction settings, and Quarkus test verification. This should trigger for requests such as Add Mongock migrations in Quarkus; Configure quarkus-mongock; Review Quarkus MongoDB data migrations; Create Mongock change units for Quarkus MongoDB; Review Mongock migration ordering in a Quarkus service. Part of Plinth Toolkit
Use when reviewing, designing, or modifying Java enterprise systems that use AI, LLMs, AI agents, RAG, tool calling, workflow automation, or model-based decision support and need EU AI Act regulatory awareness. This should trigger for requests such as Review a Java AI system for EU AI Act controls; Design governance for an AI agent with enterprise tools; Add human oversight and auditability to LLM workflows; Assess RAG or model-driven decision support before production release. Part of Plinth Toolkit
Use when reviewing, designing, or modifying Java enterprise products, services, libraries, agents, plugins, connected components, or platform modules that may qualify as products with digital elements and need EU Cyber Resilience Act secure-by-design, vulnerability handling, security update, SBOM, product documentation, or release-readiness controls. Part of Plinth Toolkit
Use when reviewing, designing, or modifying Java enterprise systems that expose, exchange, store, process, export, or port data across users, businesses, connected products, cloud providers, APIs, event streams, AI data pipelines, data spaces, or SaaS platforms and need EU Data Act engineering controls. This should trigger for requests such as Review a Java platform for EU Data Act controls; Design data access and portability evidence; Add data-sharing request workflows, export formats, interoperability, metadata, audit logs, cloud-switching support, non-personal data safeguards, or trade-secret handoffs; Assess Data Act engineering readiness before production release. Part of Plinth Toolkit
Use this skill when the user asks to “create an agent,” “add an agent,” “write a subagent,” “agent frontmatter,” “when to use description,” “agent examples,” “agent tools,” “agent colors,” or “autonomous agent,” or needs guidance on agent structure, system prompts, triggering conditions, or agent development best practices for Claude Code plugins.
This skill should be used for browser automation tasks using Chrome DevTools Protocol (CDP). Triggers when users need to launch Chrome with remote debugging, navigate pages, execute JavaScript in browser context, capture screenshots, or interactively select DOM elements. No MCP server required.
Create hierarchical project plans optimized for solo agentic development. Use when planning projects, phases, or tasks that Claude will execute. Produces Claude-executable plans with verification criteria, not enterprise documentation. Handles briefs, roadmaps, phase plans, and context handoffs.
Structure a Flutter design system as tokens→theme→modifiers→shapes with two-tier tokens (primitives named by measured value and semantic slots named by role) exposed through a ThemeExtension read via an asserting of(context); hand-author both light and dark ColorScheme instead of ColorScheme.fromSeed; keep every raw color/hex/Colors./Curves./Duration/BorderRadius/fontSize inside lib/theme/ behind a no-raw-values gate; collapse animation to zero under reduced motion, restore the persisted theme before first paint, bundle fonts (never google_fonts/dynamic_color), and derive each stateful meaning’s supporting color last so color is never its sole signal. Use when creating or editing ThemeData/ThemeExtension/ColorScheme, adding or renaming a design token, wiring theme injection or theme-mode persistence, reaching for fromSeed/dynamic_color/google_fonts/FontVariation, structuring a theme/ or DesignSystem/ folder, or reviewing any widget that renders a color, radius, duration, or font.
Remove AI-generated code slop, unnecessary comments, and over-engineering from the current branch diff. Cleans up boilerplate, simplifies abstractions, strips defensive code, and in skill-file mode lints SKILL.md files for quality. Use when cleaning up code, simplifying, removing boilerplate, before committing, or when reviewing a skill before promoting it.
Enforces a right-sized feature-first layered MVVM Flutter architecture: features are folders, and cross-cutting foundations become packages only when a compile wall warrants it; dependencies form a strictly downward-only DAG; Views stay dumb, with one Notifier/AsyncNotifier ViewModel per feature; repositories are the single source of truth and single write path, returning immutable domain values; abstractions are used only when something genuinely cannot run in a test; and Riverpod 3.x is the sole context-free DI+state mechanism (no get_it/injectable/package:provider container). Use when creating a Flutter feature or file, deciding between a folder and package or where a class belongs, naming a Screen/Notifier/Repository/Service, wiring providers or a composition-root/bootstrap.dart, adding a use-case/domain layer, avoiding over-engineering in a small app, or reviewing whether a change respects layer boundaries
New to MCP?
From what the protocol is to installing your first server, these answers cover most first questions.
An open protocol that defines how AI applications connect to external tools and data in a uniform way. Clients talk to the model; MCP servers provide tools, resources and prompt templates. They exchange standard messages, so one server can be reused by many clients.