figma-generate-library

What this skill does

# Design System Builder — Figma MCP Skill

Build professional-grade design systems in Figma that match code. This skill orchestrates multi-phase workflows across 20–100+ `use_figma` calls, enforcing quality patterns from real-world design systems (Material 3, Polaris, Figma UI3, Simple DS).

**Prerequisites**: The `figma-use` skill MUST also be loaded for every `use_figma` call. It provides Plugin API syntax rules (return pattern, page reset, ID return, font loading, color range). This skill provides design system domain knowledge and workflow orchestration.

**Always pass `skillNames: "figma-generate-library"` when calling `use_figma` as part of this skill.** This is a logging parameter — it does not affect execution.

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## 1. The One Rule That Matters Most

**This is NEVER a one-shot task.** Building a design system requires 20–100+ `use_figma` calls across multiple phases, with mandatory user checkpoints between them. Any attempt to create everything in one call WILL produce broken, incomplete, or unrecoverable results. Break every operation to the smallest useful unit, validate, get feedback, proceed.

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## 2. Mandatory Workflow

Every design system build follows this phase order. Skipping or reordering phases causes structural failures that are expensive to undo.

```
Phase 0: DISCOVERY (always first — no use_figma writes yet)
  0a. Analyze codebase → extract tokens, components, naming conventions
  0b. Inspect Figma file → pages, variables, components, styles, existing conventions
  0c. Search subscribed libraries → use search_design_system for reusable assets
  0d. Lock v1 scope → agree on exact token set + component list before any creation
  0e. Map code → Figma → resolve conflicts (code and Figma disagree = ask user)
  ✋ USER CHECKPOINT: present full plan, await explicit approval

Phase 1: FOUNDATIONS (tokens first — always before components)
  1a. Create variable collections and modes
  1b. Create primitive variables (raw values, 1 mode)
  1c. Create semantic variables (aliased to primitives, mode-aware)
  1d. Set scopes on ALL variables
  1e. Set code syntax on ALL variables
  1f. Create effect styles (shadows) and text styles (typography)
  → Exit criteria: every token from the agreed plan exists, all scopes set, all code syntax set
  ✋ USER CHECKPOINT: show variable summary, await approval

Phase 2: FILE STRUCTURE (before components)
  2a. Create page skeleton: Cover → Getting Started → Foundations → --- → Components → --- → Utilities
  2b. Create foundations documentation pages (color swatches, type specimens, spacing bars)
  → Exit criteria: all planned pages exist, foundations docs are navigable
  ✋ USER CHECKPOINT: show page list + screenshot, await approval

Phase 3: COMPONENTS (one at a time — never batch)
  For EACH component (in dependency order: atoms before molecules):
    3a. Create dedicated page
    3b. Build base component with auto-layout + full variable bindings
    3c. Create all variant combinations (combineAsVariants + grid layout)
    3d. Add component properties (TEXT, BOOLEAN, INSTANCE_SWAP)
    3e. Link properties to child nodes
    3f. Add page documentation (title, description, usage notes)
    3g. Validate: get_metadata (structure) + get_screenshot (visual)
    3h. Optional: lightweight Code Connect mapping while context is fresh
    → Exit criteria: variant count correct, all bindings verified, screenshot looks right
    ✋ USER CHECKPOINT per component: show screenshot, await approval before next component

Phase 4: INTEGRATION + QA (final pass)
  4a. Finalize all Code Connect mappings
  4b. Accessibility audit (contrast, min touch targets, focus visibility)
  4c. Naming audit (no duplicates, no unnamed nodes, consistent casing)
  4d. Unresolved bindings audit (no hardcoded fills/strokes remaining)
  4e. Final review screenshots of every page
  ✋ USER CHECKPOINT: complete sign-off
```

---

## 3. Critical Rules

**Plugin API basics** (from use_figma skill — enforced here too):
- Use `return` to send data back (auto-serialized). Do NOT wrap in IIFE or call closePlugin.
- Return ALL created/mutated node IDs in every return value
- Page context resets each call — always `await figma.setCurrentPageAsync(page)` at start. **Call it at most once per script**: each component or doc page is its own `use_figma` call. Never loop over `figma.root.children` and switch pages inside a mutating script — split that work into one focused call per target page (see [figma-use → gotchas.md → Set current page once per `use_figma` call](../figma-use/references/gotchas.md#set-current-page-once-per-use_figma-call--split-multi-page-work-across-calls))
- `figma.notify()` throws — never use it
- Colors are 0–1 range, not 0–255
- Font MUST be loaded before any text write: `await figma.loadFontAsync({family, style})`. Use `await figma.listAvailableFontsAsync()` to discover available fonts and verify exact style strings — if a load fails, query available fonts to find the correct name or a fallback.

**Design system rules**:
1. **Variables BEFORE components** — components bind to variables. No token = no component.
2. **Inspect before creating** — run read-only `use_figma` to discover existing conventions. Match them.
3. **One page per component** *(default)* — exception: tightly related families (e.g., Input + helpers) may share a page with clear section separation.
4. **Bind visual properties to variables** *(default)* — fills, strokes, padding, radius, gap. Exceptions: intentionally fixed geometry (icon pixel-grid sizes, static dividers).
5. **Scopes on every variable** — NEVER leave as `ALL_SCOPES`. Background: `FRAME_FILL, SHAPE_FILL`. Text: `TEXT_FILL`. Border: `STROKE_COLOR`. Spacing: `GAP`. Radii: `CORNER_RADIUS`. Primitives: `[]` (hidden).
6. **Code syntax on every variable** — WEB syntax MUST use the `var()` wrapper: `var(--color-bg-primary)`, not `--color-bg-primary`. Use the actual CSS variable name from the codebase. ANDROID/iOS do NOT use a wrapper.
7. **Alias semantics to primitives** — `{ type: 'VARIABLE_ALIAS', id: primitiveVar.id }`. Never duplicate raw values in semantic layer.
8. **Position variants after combineAsVariants** — they stack at (0,0). Manually grid-layout + resize.
9. **INSTANCE_SWAP for icons** — never create a variant per icon. Cap variant matrices: if Size × Style × State > 30 combinations, split into sub-component.
10. **Deterministic naming** — use consistent, unique node names for idempotent cleanup and resumability. Track created node IDs via return values and the state ledger.
11. **No destructive cleanup** — cleanup scripts identify nodes by name convention or returned IDs, not by guessing.
12. **Validate before proceeding** — never build on unvalidated work. `get_metadata` after every create, `get_screenshot` after each component.
13. **NEVER parallelize `use_figma` calls** — Figma state mutations must be strictly sequential. Even if your tool supports parallel calls, never run two use_figma calls simultaneously.
14. **Never hallucinate Node IDs** — always read IDs from the state ledger returned by previous calls. Never reconstruct or guess an ID from memory.
15. **Use the helper scripts** — embed scripts from `scripts/` into your use_figma calls. Don't write 200-line inline scripts from scratch.
16. **Explicit phase approval** — at each checkpoint, name the next phase explicitly. "looks good" is not approval to proceed to Phase 3 if you asked about Phase 1.

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## 4. State Management (Required for Long Workflows)

> **`getPluginData()` / `setPluginData()` are NOT supported in `use_figma`.** Use `getSharedPluginData()` / `setSharedPluginData()` instead (these ARE supported), or use name-based lookups and the state ledger (returned IDs).

| Entity type | Idempotency key | How to check existence |
|-------------|----------------|----------------------|
| Scene nodes (pages, frames, components) | `setSharedPluginData('dsb', 'key', value)` or unique name | `node.getSharedPluginData('dsb', 'k