Tools

Official MCP for the open-source design tool Penpot: through the Penpot plugin API, agents can query, modify and generate designs, supporting design-to-code and code-to-design. Run npx -y @penpot/mcp@latest first and load the MCP plugin in Penpot to connect.

A cat replacement with syntax highlighting, line numbers and Git change markers, plus --line-range to print specific lines. Falls back to plain text in pipes and other non-interactive use, and pairs with git diff or tail -f for code and logs.

Shapes the agent's replies for a reader with ADHD: lead with the next action, number multi-step work, restate progress every turn, hold back tangents, give concrete time estimates and make finished work visible. Turn it on with /i-have-adhd; it lasts until you say stop adhd mode.

Diagnoses website SEO issues: checks crawling and indexing, Core Web Vitals, metadata and on-page content, and gives prioritized, actionable fixes. From the marketingskills collection.

Creates a local CA with one command and issues development HTTPS certificates trusted by your system and browsers, for localhost, IPs and wildcard domains, with no extra configuration. Run mkcert -install once first to add the root certificate to the trust store.

From HKU's Data Intelligence Lab: plugins or skills for Claude Code, Codex and other agents generate agent-callable CLIs for apps like GIMP, Blender and LibreOffice, and the cli-hub package manager finds and installs ready-made community CLIs. Needs Python 3.10+.

MuseScore 4 command-line wrapper from CLI-Anything: lets agents transpose scores, extract parts, add or remove instruments, inspect score info and export PDF, MIDI, MusicXML, MP3 or braille. Handy for music teachers preparing scores in bulk. Needs MuseScore 4 and Python 3.10+.

Unified database lookup skill from K-Dense's scientific collection: reproducibly queries about 80 public database APIs such as PubChem, UniProt, ChEMBL, ClinicalTrials.gov and FRED, returning traceable results with endpoints, parameters and count checks. Some need API keys.

Guides agents to the right statistical method for research data: t-tests, ANOVA, chi-square, regression and Bayesian analysis, checking assumptions, computing effect sizes and power, and reporting results in APA format. Python-based (pingouin, statsmodels); by K-Dense.

Teaches agents standard single-cell RNA-seq analysis with Scanpy: QC, normalization, PCA/UMAP, clustering, differential expression and plots, with ready-to-run pipeline scripts and guidance on converting Seurat and other R objects to h5ad. Needs Python 3.12+; by K-Dense.

Open-source crypto trading framework: download market data, backtest and optimize strategies, and paper trade from the CLI while agents iterate on strategies. Docker recommended; strategies need Python and live trading needs exchange API keys. Backtests don't guarantee returns.

Design engineering skills by Emil Kowalski, author of Sonner and Vaul: choose animation easing and durations, review and improve motion, apply Apple design principles, make web apps feel native on phones, and help pick UI libraries and prototype multiple versions.

General-purpose AI agent that runs on your machine, with a desktop app, CLI and API. Written in Rust, works with 15+ model providers and connects to 70+ extensions via MCP. Originally from Block, now part of the Linux Foundation's AAIF.

Teaches agents to use the Chrome DevTools MCP efficiently: snapshot first to get element uids, screenshot only when needed, paginate and filter large output, inspect CSS and test browser extensions. Needs chrome-devtools-mcp configured; maintained by the Chrome DevTools team.

Agile AI-driven development method: analyst, product manager, UX designer and other role skills turn ideas into product briefs, PRDs and PRFAQs, then split them into tasks for agents. Needs a skills-capable agent such as Claude Code, plus Node.js, Git and uv; then run bmad setup.

Official Chrome plugin bundling the Chrome DevTools MCP with debugging skills for accessibility, LCP and memory leaks: lets agents drive and inspect a real Chrome and analyze network requests, console logs and performance traces. Collects usage stats by default; can be disabled.

Lets agents control and inspect a real Chrome: read the console and network requests, take screenshots, and record performance traces with optimization suggestions. Maintained by the Chrome DevTools team.

C/C++ port of OpenAI's Whisper speech recognition model that transcribes audio offline and outputs subtitles. Runs on CPU, with Apple Silicon and various GPU acceleration. Download a ggml-format model first.

Expo's official CLI: starts the React Native dev server, runs prebuild to generate native folders, runs apps locally on iOS and Android, and installs version-compatible dependencies. Ships with the expo package; call it with npx expo inside a project.

Astral's extremely fast Python linter and formatter written in Rust, replacing Flake8, isort and Black, with 900+ built-in rules and auto-fix.

Terminal multiplexer built for coding agents: run Claude Code, Codex and others in split panes, each marked working, blocked or idle, with sessions surviving disconnects. Agents can also create panes and message each other through the CLI.

Browser automation CLI built for AI agents in native Rust: open pages, click and fill forms by refs from accessibility tree snapshots, read text and take screenshots, with compact snapshots and output limits to save context. From Vercel Labs; reuses local Chrome or installs one.

Browser automation plugin from Vercel Labs: agents drive Chrome through accessibility tree snapshots and element refs to navigate, click, fill forms and take screenshots, for web testing and exploratory QA. Install the agent-browser CLI first (npm, Homebrew or Cargo).

Companion skill for the agent-browser CLI: has the agent load usage matching the installed version to navigate, fill forms, take screenshots and run exploratory tests, and can also drive Electron desktop apps. Install the agent-browser CLI first; from Vercel Labs.