emcn-design-review
This slash command reviews UI code for compliance with the emcn design system, a custom component library built on Radix UI. It validates component usage, CSS variable tokens, button variants, and design patterns against the emcn specification. Use it when developing or reviewing features to ensure consistent alignment with emcn standards, with the option to automatically apply fixes or only propose recommendations.
git clone --depth 1 https://github.com/simstudioai/sim /tmp/emcn-design-review && cp -r /tmp/emcn-design-review/.agents/skills/emcn-design-review ~/.claude/skills/emcn-design-reviewSKILL.md
# EMCN Design Review
Arguments:
- scope: what to review (default: your current changes). Examples: "diff to main", "PR #123", "src/components/", "whole codebase"
- fix: whether to apply fixes (default: true). Set to false to only propose changes.
User arguments: $ARGUMENTS
## Context
This codebase uses **emcn**, a custom component library built on Radix UI primitives with CVA variants and CSS variable design tokens. All UI must use emcn components and tokens.
## Steps
1. Read the emcn public barrel at `packages/emcn/src/index.ts` (re-exports components, Calendar, Table*, and icons) to know what's available; for the full icon set read `packages/emcn/src/icons/index.ts`
2. Read `apps/sim/app/_styles/globals.css` for CSS variable tokens
3. Analyze the specified scope against every rule below
4. If fix=true, apply the fixes. If fix=false, propose the fixes without applying.
---
## Imports
- Import from `@/components/emcn` barrel, never subpaths
- Icons from `@sim/emcn/icons`
- Use `cn` from `@/lib/core/utils/cn` for conditional classes
## Design Tokens
Use CSS variable pattern (`text-[var(--text-primary)]`), never Tailwind semantics (`text-muted-foreground`) or hardcoded colors (`text-gray-500`, `#333`).
**Text**: `--text-primary`, `--text-secondary`, `--text-tertiary`, `--text-muted`, `--text-body` (canonical value text), `--text-icon`, `--text-placeholder`, `--text-subtle`, `--text-inverse`, `--text-error`
**Surfaces**: `--bg`, `--surface-1` through `--surface-7`, `--surface-hover`, `--surface-active`
**Borders**: `--border`, `--border-1`, `--border-muted`
**Brand/accent**: `--brand-secondary`, `--brand-accent`
**Z-Index**: `--z-dropdown` (100), `--z-toast` (150), `--z-modal` (200), `--z-popover` (300), `--z-tooltip` (400), `--z-takeover` (500), `--z-shell-gate` (600)
**Shadows**: `shadow-subtle`, `shadow-medium`, `shadow-overlay`, `shadow-card`
**Badges**: `--badge-*` semantic families (success/error/gray/blue/purple/orange/amber/teal/cyan/pink, each with `-bg`/`-text`)
## Buttons
Intent-to-variant mapping (read the actual `buttonVariants` in `packages/emcn/src/components/button/button.tsx` for the full variant set — it exposes more than listed here):
| Action | Variant |
|--------|---------|
| Toolbar, icon-only | `ghost` |
| Create, save, submit | `primary` |
| Cancel, close | `default` |
| Delete, remove | `destructive` |
| Selected state | `active` |
| Toggle | `outline` |
## Delete/Remove Confirmations
`ChipModal` `size='sm'`, title "Delete/Remove {ItemType}", destructive confirm button, plain Cancel (follow the chip footer layout in `.claude/rules/emcn-components.md`). Use `text-[var(--text-error)]` for irreversible warnings.
## Toast
`toast.success()`, `toast.error()`, `toast()` from `@/components/emcn`. Never custom notification UI.
## Badges
`red`=error/failed, `gray-secondary`=metadata/roles, `type`=type annotations, `green`=success/active, `gray`=neutral, `amber`=processing, `orange`=paused, `blue`=info. Use `dot` prop for status indicators.
## Icons
Default: `size-[14px]`. Color: `text-[var(--text-icon)]`. Scale: 14px > 16px > 12px > 20px. Use the `size-*` shorthand — flag `h-[Npx] w-[Npx]` and `h-N w-N` pairs as refactor targets.
## Anti-patterns to flag
- Raw `<button>`/`<input>`, or legacy `Input`/`Textarea`/`Modal`, instead of the canonical chip components (`ChipInput`/`ChipTextarea`/`ChipModal`)
- Hand-rolled field rows inside a `ChipModalBody` instead of `ChipModalField`
- Hardcoded colors (`text-gray-*`, `#hex`, `rgb()`)
- Tailwind semantics (`text-muted-foreground`) instead of CSS variables
- Template literal className instead of `cn()`
- Inline styles for colors/static values (dynamic values OK)
- Importing from emcn subpaths instead of barrel
- Arbitrary z-index instead of tokens
- Wrong button variant for action typeCreate or update a Sim integration block with correct subBlocks, conditions, dependsOn, modes, canonicalParamId usage, outputs, and tool wiring. Use when working on `apps/sim/blocks/blocks/{service}.ts` or aligning a block with its tools.
Add or update a Sim knowledge base connector for syncing documents from an external source, including auth mode, config fields, pagination, document mapping, tags, and registry wiring. Use when working in `apps/sim/connectors/{service}/` or adding a new external document source.
Add a code-defined table enrichment (registry entry) under `apps/sim/enrichments/` backed by an ordered provider cascade, ensuring every provider tool it calls has hosted-key support. Use when adding a per-row table enrichment that fills cells via existing Sim tools.
Add hosted API key support to a tool so Sim provides the key (metered and billed to the workspace) when a user has not brought their own. Use when adding a `hosting` config to a tool under `apps/sim/tools/{service}/`.
Add a complete Sim integration from API docs, covering tools, block, icon, optional triggers, registrations, resolved-secret/model-input safety, and integration conventions. Use when introducing a new service under `apps/sim/tools`, `apps/sim/blocks`, and `apps/sim/triggers`.
Add a new LLM model to apps/sim/providers/models.ts with specs verified against the provider's live API docs (no hallucination)
Create tool configurations for a Sim integration by reading API docs
Create webhook or polling triggers for a Sim integration