posthog-ui-skills
Posthog's UI design system. Use when building interfaces inspired by Posthog's aesthetic - dark mode, Inter font, 4px grid.
What this skill does
# Posthog UI Skills Opinionated constraints for building Posthog-style interfaces with AI agents. ## When to Apply Reference these guidelines when: - Building dark-mode interfaces - Creating Posthog-inspired design systems - Implementing UIs with Inter font and 4px grid ## Colors - MUST use dark backgrounds (lightness < 20) for primary surfaces - detected lightness: 0 - MUST use `#000000` as page background (`surface-base`) - SHOULD limit color palette to 5 distinct colors - MUST maintain text contrast ratio of at least 4.5:1 for accessibility ### Semantic Tokens | Token | HEX | RGB | Usage | |-------|-----|-----|-------| | `surface-base` | #000000 | rgb(0,0,0) | Page background | | `surface-raised` | #E38B20 | rgb(227,139,32) | Cards, modals, raised surfaces | | `text-primary` | #52290C | rgb(82,41,12) | Headings, body text | | `text-secondary` | #55554A | rgb(85,85,74) | Secondary, muted text | | `border-default` | #C17C25 | rgb(193,124,37) | Subtle borders, dividers | | `destructive` | #52290C | rgb(82,41,12) | Error states, delete actions | | `warning` | #C17C25 | rgb(193,124,37) | Warning states, cautions | ## Typography - MUST use `Inter` as primary font family - SHOULD use single font family for consistency - MUST use `14px` / `400` for primary headings - MUST limit font weights to: regular, light - MUST use `text-balance` for headings and `text-pretty` for body text - SHOULD use `tabular-nums` for numeric data - NEVER modify letter-spacing unless explicitly requested ### Text Styles | Style | Font | Size | Weight | Color | Count | |-------|------|------|--------|-------|-------| | `heading-1` | Inter | 14px | 400 | #626257 | 1 | | `heading-2` | Inter | 13px | 300 | #545449 | 1 | | `heading-3` | Inter | 12px | 400 | #5B5B50 | 1 | | `caption` | Inter | 11px | 400 | #58584D | 1 | | `label` | Inter | 10px | 400 | #52290C | 1 | | `label` | Inter | 10px | 400 | #55554A | 1 | | `label` | Inter | 10px | 400 | #56564B | 1 | ### Typography Reference **Font Families:** - `Inter` (used 7x) **Font Sizes:** 10px, 11px, 12px, 13px, 14px ## Spacing - MUST use 4px grid for spacing - SHOULD use spacing from scale: 3px, 4px, 9px, 10px - SHOULD use 4px as default gap between elements - NEVER use arbitrary spacing values (use design scale) - SHOULD maintain consistent padding within containers ## Borders - MUST use border-radius from scale: 3px - MUST use 1px border width consistently - SHOULD use 3px as default border-radius - NEVER use arbitrary border-radius values (use design scale) - SHOULD use subtle borders (1px) for element separation ### Border Radius Reference **Scale:** 3px ## Layout - MUST design for 1920px base viewport width - SHOULD use consistent element widths: 41px, 24px, 43px, 857px, 12px - NEVER use `h-screen`, use `h-dvh` for full viewport height - MUST respect `safe-area-inset` for fixed elements - SHOULD use `size-*` for square elements instead of `w-*` + `h-*` ### Detected Layout Patterns - **Header**: height: 39px - **Main Content**: width: 1920px, height: 1050px - **Main Content**: width: 1920px, height: 1043px ## Components ### Buttons | Variant | Background | Text | Border | Height | Radius | |---------|------------|------|--------|--------|--------| | Ghost | transparent | #52290C | none | - | - | ## Interactive States ### Focus - MUST use `2px` outline with accent color (`#5E6AD2`) - MUST use `2px` outline-offset - NEVER remove focus indicators ### Hover - Buttons (primary): lighten background by 10% - Buttons (secondary): use `#E38B20` background - List items: use `#E38B20` background ### Disabled - MUST use `opacity: 0.5` - MUST use `cursor: not-allowed` ## Interaction - MUST use an `AlertDialog` for destructive or irreversible actions - SHOULD use structural skeletons for loading states - MUST show errors next to where the action happens - NEVER block paste in `input` or `textarea` elements - MUST add an `aria-label` to icon-only buttons ## Animation - NEVER add animation unless it is explicitly requested - MUST animate only compositor props (`transform`, `opacity`) - NEVER animate layout properties (`width`, `height`, `top`, `left`, `margin`, `padding`) - SHOULD use `ease-out` on entrance animations - NEVER exceed `200ms` for interaction feedback - SHOULD respect `prefers-reduced-motion` ## Performance - NEVER animate large `blur()` or `backdrop-filter` surfaces - NEVER apply `will-change` outside an active animation - NEVER use `useEffect` for anything that can be expressed as render logic
Related in Design
contribute
IncludedLocal-only OSS contribution command center. Auto-refreshes the user's in-flight PR and issue state on invoke so conversations start with full context — no need to brief Claude on what's in flight. Helps the user find issues to contribute to on GitHub, builds per-repo dossiers of what each upstream expects (CLA, DCO, branch convention, AI policy, draft-first, review bots, issue templates), runs deterministic gates before any external action so AI-assisted contributions don't reach maintainers as slop. State is markdown-only: candidate files at ~/.contribute-system/candidates/, repo dossiers at ~/.contribute-system/research/, append-only event log at ~/.contribute-system/log.jsonl. No database, no cloud calls. Use when the user asks about their PRs / issues / contributions, wants to find new work to take on, claim an issue, build/refresh a repo's dossier, or draft a Design Issue or PR. Trigger with "/contribute", "what's my PR status", "find a contribution", "claim issue X", "draft a Design Issue for Y", "refresh dossier for Z".
architectural-analysis
IncludedUser-triggered deep architectural analysis of a codebase or scoped subtree across eight modes — information architecture, data flow, integration points, UI surfaces, interaction patterns, data model, control flow, and failure modes. This skill should be used when the user asks to "diagram this codebase," "map the architecture," "show the data flow," "give me an ERD," "trace control flow," "find the integration points," "verify the layout pattern," "audit the UX architecture," or any similar request whose primary deliverable is mermaid diagrams plus cited reports under docs/architecture/. Dispatches haiku/sonnet sub-agents in parallel for per-mode exploration, then verifies every citation mechanically before any node lands in a diagram. Not for one-off prose explanations of code (use code-explanation) or for high-level system design from scratch (use system-design).
mcp
IncludedModel Context Protocol (MCP) server development and tool management. Languages: Python, TypeScript. Capabilities: build MCP servers, integrate external APIs, discover/execute MCP tools, manage multi-server configs, design agent-centric tools. Actions: create, build, integrate, discover, execute, configure MCP servers/tools. Keywords: MCP, Model Context Protocol, MCP server, MCP tool, stdio transport, SSE transport, tool discovery, resource provider, prompt template, external API integration, Gemini CLI MCP, Claude MCP, agent tools, tool execution, server config. Use when: building MCP servers, integrating external APIs as MCP tools, discovering available MCP tools, executing MCP capabilities, configuring multi-server setups, designing tools for AI agents.
react-native-skia
IncludedDesign, build, debug, and optimise high-polish animated graphics in React Native or Expo using @shopify/react-native-skia, Reanimated, and Gesture Handler. Use when the user wants canvas-driven UI, shaders, paths, rich text, image filters, sprite fields, Skottie, video frames, snapshots, web CanvasKit setup, or performance tuning for custom motion-heavy elements such as loaders, hero art, cards, charts, progress indicators, particle systems, or gesture-driven surfaces. Also use when the user asks for fluid, glow, glass, blob, parallax, 60fps/120fps, or GPU-friendly animated effects in React Native, even if they do not explicitly say "Skia". Do not use for ordinary form/layout work with standard views.
plaid
IncludedProduct Led AI Development — guides founders from idea to launched product. Six capabilities: Idea (discover a product idea), Validate (pressure-test the idea against fatal flaws, problem reality, competition, and 2-week MVP feasibility), Plan (vision intake + document generation), Design (translate image references into a design.md spec), Launch (go-to-market strategy), and Build (roadmap execution). Use when someone says "PLAID", "plaid idea", "help me find an idea", "product idea", "idea from my business", "idea from my expertise", "plaid validate", "validate my idea", "pressure-test", "is this idea good", "find fatal flaws", "validate the problem", "plan a product", "define my vision", "generate a PRD", "product strategy", "plaid design", "design from image", "translate image to design", "create design.md", "extract design tokens", "plaid launch", "go-to-market", "launch plan", "GTM strategy", "launch playbook", "plaid build", "build the app", "start building", or "execute the roadmap".
nextjs-framer-motion-animations
IncludedAdds production-safe Motion for React or Framer Motion animations to Next.js apps, including reveal, hover and tap micro-interactions, whileInView, stagger, AnimatePresence, layout and layoutId transitions, reorder, scroll-linked UI, and lightweight route-content transitions. Use when the user asks to add, refactor, or debug Motion or Framer Motion in App Router or Pages Router codebases, especially around server/client boundaries, reduced motion, LazyMotion, bundle size, hydration, or route transitions. Avoid for GSAP-style timelines, WebGL or 3D scenes, heavy scroll storytelling, or CSS-only effects unless Motion is explicitly requested.