This skill should be used when comparing two videos to analyze compression results or quality differences. Generates interactive HTML reports with quality metrics (PSNR, SSIM) and frame-by-frame visual comparisons. Triggers when users mention "compare videos", "video quality", "compression analysis", "before/after compression", or request quality assessment of compressed videos.

Create Farcaster accounts and post casts autonomously. Official skill from the Farcaster team.

Mobile-first design thinking and decision-making for iOS and Android apps. Touch interaction, performance patterns, platform conventions. Teaches principles, not fixed values. Use when building React Native, Flutter, or native mobile apps.

libweb - Web extension utilities. authMiddleware validates JWT tokens. corsMiddleware handles cross-origin requests. validationMiddleware validates request bodies against JSON schema. createAuthMiddleware, createCorsMiddleware, createValidation are factories for customization. Use for securing HTTP APIs, request validation, and CORS handling with Hono framework.

libvector - Vector similarity search. VectorIndex stores embeddings with metadata and performs cosine similarity search. VectorProcessor handles embedding generation and indexing. Supports filtering by metadata and threshold-based retrieval. Use for semantic search, RAG retrieval, and similarity matching.

librc - Service lifecycle manager using svscan supervision. ServiceManager communicates with supervision daemon via Unix sockets. startServices and stopServices control multiple services. Use for starting/stopping platform services, process supervision, and service orchestration.

libperf - Performance testing utilities. benchmark function measures execution time and memory. validateDuration and validateMemory assert performance constraints. ScalingAnalyzer detects linear vs sublinear scaling. PerfRunner orchestrates benchmark suites. Use for performance testing, benchmarking, and detecting performance regressions.

Master context engineering for AI agent systems. Use when designing agent architectures, debugging context failures, optimizing token usage, implementing memory systems, building multi-agent coordination, evaluating agent performance, or developing LLM-powered pipelines. Covers context fundamentals, degradation patterns, optimization techniques, compression strategies, memory architectures, multi-agent patterns, evaluation, tool design, and project development.

Use when building, refactoring, or documenting Graft apps and proxies, including when asked to create a tool server, API server, dual-protocol server, or MCP-HTTP bridge. Graft's core thesis: define tools once and serve them as both HTTP REST endpoints and MCP tools from the same server, with discovery, docs, and OpenAPI generated automatically. Covers concrete actions such as defining tools and handlers, configuring authentication middleware, setting up HTTP and stdio transports, generating OpenAPI documentation, wrapping existing APIs via proxy mode, and wiring up the full CLI workflow.

Use when writing, reviewing, or debugging pure Ruby code — idiomatic patterns, modern 3.x+ features (pattern matching, Data.define, endless methods), error handling conventions (raise vs fail, result objects), memoization, and performance idioms. For Rails use rails-guides. For testing use minitest. For code style use sandi-metz-rules.

This skill should be used when the user asks to "create an MCP App", "build a new MCP server with a UI", "build an interactive MCP View", "scaffold a new MCP App project", "build an MCP App from scratch", or needs guidance on MCP Apps SDK patterns, UI-resource registration, MCP App lifecycle, or host integration. Provides comprehensive guidance for building MCP Apps with interactive UIs.

This skill should be used when the user asks to "add an app to my MCP server", "add UI to my MCP server", "add a view to my MCP tool", "enrich MCP tools with UI", "add interactive UI to existing server", "add MCP Apps to my server", or needs to add interactive UI capabilities to an existing MCP server that already has tools. Provides guidance for analyzing existing tools and adding MCP Apps UI resources.

Runs SEO and AEO (Answer Engine Optimization) analysis on websites or specific pages. Use when the user mentions SEO, AEO, search rankings, search optimization, or wants to analyze how their pages perform in search engines and AI answers. Produces a data dashboard and action report with before/after recommendations.

Airtable bases, tables, and records via uni CLI. Use when user wants to query Airtable data, create/update records, or list bases and tables. Requires AIRTABLE_API_KEY (Personal Access Token).

Respond to a ransomware incident following PICERL methodology. Use when ransomware is detected or suspected. Orchestrates identification, containment, eradication, and recovery phases. Requires CASE_ID and initial indicators.

Respond to a potentially compromised user account. Use when impossible travel, credential stuffing, successful phishing, or suspicious activity indicates account compromise. Investigates activity, contains the account, removes persistence, and restores access.

Close a case or alert with proper reason and documentation. Use when triage determines an alert is FP/BTP or investigation is complete. Requires artifact ID, type, closure reason, and root cause.

Audit Xcode project configuration, build settings, scheme behavior, and script phases to find build-time improvements with explicit approval gates. Use when a developer wants project-level build analysis, slow incremental builds, guidance on target dependencies, build settings review, run script phase analysis, parallelization improvements, or module-map and DEFINES_MODULE configuration.

Analyze Swift Package Manager dependencies, package plugins, module variants, and CI-oriented build overhead that slow Xcode builds. Use when a developer suspects packages, plugins, or dependency graph shape are hurting clean or incremental build performance, mentions SPM slowness, package resolution time, build plugin overhead, duplicate module builds from configuration drift, circular dependencies between modules, oversized modules needing splitting, or modularization best practices.

Use for debugger-driven runtime root-cause analysis in Rider-supported solutions and projects, including .NET/C#, F#, VB, C++, Unity, Unreal Engine, and other GameDev or mixed-language projects. Trigger when runtime state or control-flow evidence is needed — actual values, branch taken, call order, thread context, whether execution reaches a chosen line — and cannot be derived confidently from source or logs; when pinning the relevant path would otherwise mean reading many files or tracing a deep call chain; or on an explicit request to debug, set breakpoints, step, or inspect runtime values. Do not use for compile-time or syntax errors, source-obvious bugs, failures already pinpointed by logs/tests, or code merely named debug/Debugger.