DEVELOPER TOOLING INTERNAL TOOLING JSON SCHEMA GENERATION

Design Token MCP Server

Claude Model Context Protocol Bridge & Schema Syncer

ROLE AI Tooling Developer

CORE TECHNOLOGIES

MCP Protocol Claude AI Figma API TypeScript

PRIMARY HIGHLIGHT Standardized Model Context Protocol (MCP) Zero-latency Figma token extraction

LINKS & ACCESS

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01. Context & Overview

Built an enterprise Model Context Protocol (MCP) server that connects Anthropic Claude directly to Figma design tokens and component canvases.

Instead of developers manually translating spacing, color palettes, and typographic hierarchies from Figma files into code, Claude queries the local MCP server over standard JSON-RPC 2.0 to compile strictly-typed TypeScript token definitions automatically.

02. The Constraints & Needs

Bridging design systems with generative AI presents unique challenges:

Figma Canvas AST Complexity: Raw Figma document trees contain thousands of deeply nested vector nodes, which exceed LLM context window limits if dumped unformatted.
Deterministic Output Requirement: Token schemas must match the organization’s Tailwind and TypeScript configurations with zero type drift.
Protocol Standardization: Adhering to Anthropic’s Model Context Protocol specification ensures compatibility with desktop and IDE clients.

MCP_TokenPayload

v1.1.0 · DATA CONTRACT

// Contract schema definition

{

"token_namespace": *req <string> // Design system category (color, spacing, typo)

"value_hex_rem": *req <string> // Computed CSS value or OKLCH token

"figma_node_id": *req <string> // Upstream source node in Figma file

"contrast_ratio": <float> // APCA perceptual contrast score

}

03. System Architecture & Data Flow

ARCHITECTURE SCHEMATIC

Figma-to-Claude MCP Translation Pipeline

PIPELINE FLOW

Claude Client MCP Handshake JSON-RPC 2.0 / STDIO

Claude establishes connection and discovers available MCP tool capabilities: query_tokens and compile_components.

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Figma REST API AST Pruner CANVAS TREE PRUNING

Extracts document nodes, strips layout noise, and maps raw styles into semantic token groups.

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TypeScript Compiler API Verification TYPESCRIPT AST

Generates strict .d.ts token contracts and runs in-memory type checks before presenting to the LLM.

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Ready-to-Ship Code Generation TAILWIND / REACT EXPORT

Claude outputs production components utilizing verified design system variables.

04. Protocol & Sequence Lifecycle

PROTOCOL LIFECYCLE

Claude MCP Request Sequence

SEQUENCE TRACE

Claude Client

MCP Host

Figma API

TS Compiler

#1 Claude Client → MCP Host : Call: tools/call { name: 'get_tokens' }

1ms

#2 MCP Host → Figma API : GET: /v1/files/:file_key/styles

180ms

#3 Figma API → MCP Host : Return raw JSON node styles

45ms

#4 MCP Host → TS Compiler : Format & validate into TokenSchema

12ms

#5 TS Compiler → MCP Host : Emit typed declarations

8ms

#6 MCP Host → Claude Client : Return formatted tokens in context window

2ms

05. Benchmark & Evaluation Matrix

ARCHITECTURE MATRIX

Design-to-Code Velocity Metrics

Based on Standard 40-Component Design System Library

TRADE-OFFS

swipe Swipe horizontally to inspect full matrix

Area / Decision	Conventional Approach	Chosen Solution	Trade-Off & Impact
Token Translation Time	3–4 Hours (Manual typing & QA)	< 15 Seconds (MCP Tool Call)	99% Faster Turnaround
Typography / Color Drift	6–12 type errors per release	0 errors (Strict TS Compiler check)	Zero Token Mismatches
Context Window Efficiency	125,000 tokens (Raw Figma JSON)	3,200 tokens (Pruned AST payload)	97% Context Savings

06. Production Learnings & Architecture Rules

Prune the AST Before Ingestion: Never pass raw API trees to language models; filter out 95% of visual metadata that is irrelevant to token extraction.
Standardize on MCP: By building against Anthropic’s Model Context Protocol, the server works seamlessly across Claude Desktop, CLI, and custom agents.

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