Outils

Has the agent commit to a visual direction before building or redesigning an interface, making deliberate choices on color, type and layout instead of generic, templated AI UI. Official Anthropic skill.

Guides the agent through writing or improving a skill: clarify intent, draft SKILL.md, run scored evals with and without the skill, then tune the description so it triggers accurately. Official Anthropic skill.

166 research skills maintained by K-Dense (formerly Claude Scientific Skills), spanning bioinformatics, cheminformatics, clinical research, materials and physics, including unified access to 78 public databases such as PubChem and UniProt. Works with Claude Code, Codex and Cursor.

Before you build, the agent grills you on your plan or design, offering a recommended answer each round, until every decision branch is resolved. It calls the grilling skill from the same repo, so install both.

Resolves subscription billing issues: checks customer and subscription state, separates duplicate purchases, team seats and failed payments, restores self-serve before refunding, and drafts the reply. Needs Stripe or similar tools connected; refunds move real money, so review them.

Develops a design philosophy first, then draws posters, illustrations and other static visuals in code, exporting PNG or PDF. Emphasizes original work rather than copying existing artists. Official Anthropic skill.

Makes GIFs that follow Slack's recommended size, frame rate, color and length for emoji (128x128) and message GIFs (480x480), with animation tips and tools to assemble and validate them. Built on Python and Pillow. Official Anthropic skill.

After giving advice, a draft or a data analysis, adds 2-3 targeted follow-up questions that prompt the user to check key facts, test the reasoning and fill in missing context. Fires at most once per conversation. Official Anthropic skill.

Creates generative art such as flow fields and particle systems with p5.js and seeded randomness: first writes an algorithmic design philosophy, then outputs an interactive HTML viewer with tunable parameters. Official Anthropic skill.

Writes internal communications in familiar company formats: 3P updates, leadership reports, project status updates, company newsletters, FAQs and incident reports. Official Anthropic skill.

Ten built-in color and font themes to apply to slides, documents, reports and HTML landing pages, or generate a new theme on demand. Official Anthropic skill.

Reference for the Claude API and Anthropic SDK: model selection and pricing, streaming, tool use, prompt caching, Managed Agents and more, plus workflows for model migration and prompt audits. Official Anthropic skill.

Guides agents in building quality MCP servers: research the protocol and target API, design tools, implement with Python (FastMCP) or the TypeScript SDK, and write evaluation questions to test the result. Official Anthropic skill.

Creates, reads and edits PowerPoint decks: applies templates and layouts, handles speaker notes and comments, and merges or splits slides. The official Anthropic skill behind Claude's document features; source-available, not open source.

Skill pack from YC president Garry Tan: slash commands such as /office-hours, /plan-ceo-review, /review, /qa and /ship play CEO, engineering manager, designer, QA and release engineer. Needs Git and Bun; clone the repo and run ./setup as the README describes.

YC office hours skill from gstack: startup mode tests real demand, the narrowest wedge and future fit with six probing questions; builder mode brainstorms side projects, hackathons and open source. Ends with a design doc. Maintained by Garry Tan.

UI design knowledge base skill: looks up UI styles, palettes, font pairings, charts and UX guidelines by product type and generates a full design system, covering 22 stacks including React, SwiftUI and Flutter. Needs Python 3 locally.

Generates or edits images: photos, illustrations, textures, game sprites, product mockups and transparent assets. A built-in Codex system skill using the image_gen tool, no install needed; with approval it can use a bundled CLI script that needs OPENAI_API_KEY. By OpenAI.

Official shadcn/ui skill: uses the shadcn CLI to read project config and component docs, then adds, searches, composes and fixes components following styling, form and accessibility rules. Can also start new projects from presets.

For fuzzy requirements: the agent asks one question at a time with its own guess, clarifying users, motivation, success criteria and constraints, and restates the intent for your confirmation before planning. Needs you answering live, so not for unattended runs. From Addy Osmani's agent-skills.

Helps agents build frontends that don't look templated: picks a design direction first, then tunes layout variance, motion intensity and information density. Also includes redesign audits, minimalist and brutalist styles, and design reference generation.

Frontend design polish skill: one skill with 24 commands such as polish, audit, critique and typeset, plus 61 deterministic rules that catch typical AI-generated UI problems, with live iteration in the browser. Works with Claude Code, Codex, Cursor and others.

Reads messy invoices and receipts (PDFs, scans, screenshots), extracts vendor, date and amount, renames and files them by vendor, category or year, keeps originals and can export a CSV for your accountant. Needs an agent with local file access; no account required.

HeyGen's official HyperFrames skill set: lets agents write deterministic MP4 videos in HTML, CSS and animation, with workflows for promo videos, explainers, captions and beat-synced music. Needs Node.js 22+ and FFmpeg.