Shared Package - TemPad Dev

Overview

The shared package (@tempad-dev/shared) provides shared contracts, schemas, and types used by both the browser extension and MCP server. Location: packages/shared/ NPM Package: @tempad-dev/shared (private) Repository: https://github.com/ecomfe/tempad-dev

Responsibilities

Zod schemas for MCP tools
TypeScript types for tool parameters and results
Constants for payload and message limits
WebSocket protocol types
Figma utility functions (color, gradient, stroke)

Tech Stack

Language: TypeScript
Schemas: Zod
Build Tool: tsdown

Directory Structure

packages/shared/
├── src/
│   ├── index.ts              # Public exports
│   ├── mcp/
│   │   ├── constants.ts      # Payload and message limits
│   │   ├── tools.ts          # Tool schemas and result types
│   │   ├── protocol.ts       # WebSocket message shapes
│   │   ├── errors.ts         # Error types
│   │   └── index.ts          # MCP exports
│   └── figma/
│       ├── color.ts          # Color formatter utilities
│       ├── gradient.ts       # Gradient utilities
│       ├── stroke.ts         # Stroke utilities
│       ├── style-resolver.ts # Style resolution
│       └── index.ts          # Figma exports
├── tests/                    # Test files
│   ├── mcp/
│   │   └── tools.test.ts
│   └── figma/
│       └── color.test.ts
├── tsdown.config.ts          # Build configuration
└── package.json

Key Commands

Building

# From root (usually runs automatically)
pnpm build

# From package directory
pnpm -C packages/shared build

# Or with filter
pnpm --filter @tempad-dev/shared build

Output:

dist/index.js - ESM export
dist/index.d.ts - TypeScript types
dist/mcp/ - MCP schemas and types
dist/figma/ - Figma utilities

Testing

# Run tests
pnpm -C packages/shared test:run

# With coverage
pnpm -C packages/shared test:coverage

# Watch mode
pnpm -C packages/shared test

Quality Checks

# Typecheck
pnpm -C packages/shared typecheck

# Lint
pnpm -C packages/shared lint
pnpm -C packages/shared lint:fix

# Format
pnpm -C packages/shared format
pnpm -C packages/shared format:check

MCP Schemas

Tool Schemas

File: src/mcp/tools.ts Defines Zod schemas for all MCP tools:

import { z } from 'zod'

// get_code parameters
export const GetCodeParametersSchema = z.object({
  nodeId: z.string(),
  lang: z.enum(['react', 'vue', 'html']).optional(),
  // ... more fields
})

export type GetCodeParameters = z.infer<typeof GetCodeParametersSchema>

// get_code result
export const GetCodeResultSchema = z.object({
  lang: z.string(),
  code: z.string(),
  assets: z.array(AssetSchema).optional(),
  warnings: z.array(z.string()).optional()
})

export type GetCodeResult = z.infer<typeof GetCodeResultSchema>

Constants

File: src/mcp/constants.ts Defines limits and constraints:

// Payload limits
export const MAX_PAYLOAD_SIZE = 10 * 1024 * 1024  // 10MB
export const MAX_ASSET_SIZE = 5 * 1024 * 1024     // 5MB

// Message constants
export const REQUEST_TIMEOUT_MS = 30000  // 30s

Protocol Types

File: src/mcp/protocol.ts WebSocket message shapes:

export type WSMessage =
  | { type: 'request'; id: string; tool: string; params: unknown }
  | { type: 'response'; id: string; result: unknown }
  | { type: 'error'; id: string; error: string }

Figma Utilities

Color Formatting

File: src/figma/color.ts Color conversion utilities:

export function formatColor(color: RGB): string {
  const r = Math.round(color.r * 255)
  const g = Math.round(color.g * 255)
  const b = Math.round(color.b * 255)
  return `#${r.toString(16).padStart(2, '0')}${g.toString(16).padStart(2, '0')}${b.toString(16).padStart(2, '0')}`
}

Gradient Utilities

File: src/figma/gradient.ts Gradient formatting for CSS:

export function formatGradient(paint: GradientPaint): string {
  // Convert Figma gradient to CSS linear-gradient
}

Stroke Utilities

File: src/figma/stroke.ts Stroke formatting for CSS:

export function formatStroke(stroke: Paint): string {
  // Convert Figma stroke to CSS border
}

Code Style Guidelines

Additive Schema Changes

Good: Add optional fields

const GetCodeResultSchema = z.object({
  lang: z.string(),
  code: z.string(),
  warnings: z.array(z.string()).optional()  // New optional field
})

Avoid: Breaking changes

// Bad: Removed required field
const GetCodeResultSchema = z.object({
  lang: z.string()
  // code field removed - BREAKING
})

Type Inference

Always infer types from Zod schemas:

export const MySchema = z.object({ /* ... */ })
export type MyType = z.infer<typeof MySchema>

Do not manually duplicate types.

Testing Strategy

Strict Pure Coverage

These files have enforced coverage:

src/index.ts
src/mcp/constants.ts
src/mcp/errors.ts
src/mcp/index.ts
src/mcp/protocol.ts
src/mcp/tools.ts
src/figma/index.ts
src/figma/color.ts
src/figma/gradient.ts
src/figma/stroke.ts
src/figma/style-resolver.ts

Test Files

Location: tests/ Pattern: *.test.ts (Node runtime only)

Example Test

import { describe, it, expect } from 'vitest'
import { formatColor } from '../src/figma/color'

describe('formatColor', () => {
  it('converts RGB to hex', () => {
    expect(formatColor({ r: 1, g: 0, b: 0 })).toBe('#ff0000')
  })

  it('handles fractional values', () => {
    expect(formatColor({ r: 0.5, g: 0.5, b: 0.5 })).toBe('#808080')
  })
})

Boundaries and Constraints

Coordinated Schema Changes

Never change schemas without updating downstream packages:

Update shared - Make schema change
Update mcp-server - Handle new schema
Update extension - Use new schema

Validation order:

pnpm --filter @tempad-dev/shared test:run
pnpm --filter @tempad-dev/mcp test:run
pnpm --filter @tempad-dev/extension test:run

Asset URI Format

Do not change asset:// URI format without cross-package review.

Payload Caps

Changing MAX_PAYLOAD_SIZE or MAX_ASSET_SIZE requires:

Extension validation
MCP server validation
Documentation update

Dependencies

Do not add new dependencies without approval. Current dependencies:

zod - Schema validation (required)

Verification Checklist

Always Run

pnpm -C packages/shared typecheck
pnpm -C packages/shared lint
pnpm -C packages/shared test:run

Coverage Check

pnpm -C packages/shared test:coverage

Downstream Validation

After schema changes:

# Build shared first
pnpm --filter @tempad-dev/shared build

# Validate downstream packages
pnpm --filter @tempad-dev/mcp build
pnpm --filter @tempad-dev/mcp test:run

pnpm --filter @tempad-dev/extension build
pnpm --filter @tempad-dev/extension test:run

Change Migration Strategy

Adding Optional Fields

Add field with .optional() in Zod schema
Update TypeScript types (auto-inferred)
Test in isolation
Update downstream packages

Deprecating Fields

Mark field as deprecated in comments
Make field optional if not already
Update downstream packages to stop using
Remove in next major version

Renaming Fields

Avoid renaming. Instead:

Add new field
Deprecate old field
Support both during transition
Remove old field in major version

Package Configuration

Exports

From package.json:

{
  "main": "dist/index.js",
  "types": "dist/index.d.ts",
  "exports": {
    ".": {
      "types": "./dist/index.d.ts",
      "import": "./dist/index.js"
    }
  }
}

Files

Only dist/ is published (if package were public):

{
  "files": ["dist"]
}

In source repo:

Testing architecture: docs/testing/architecture.md
Extension requirements: docs/extension/requirements.md
Extension design: docs/extension/design.md

In this site:

Contributing

Packages

​Overview

​Responsibilities

​Tech Stack

​Directory Structure

​Key Commands

​Building

​Testing

​Quality Checks

​MCP Schemas

​Tool Schemas

​Constants

​Protocol Types

​Figma Utilities

​Color Formatting

​Gradient Utilities

​Stroke Utilities

​Code Style Guidelines

​Additive Schema Changes

​Type Inference

​Testing Strategy

​Strict Pure Coverage

​Test Files

​Example Test

​Boundaries and Constraints

​Coordinated Schema Changes

​Asset URI Format

​Payload Caps

​Dependencies

​Verification Checklist

​Always Run

​Coverage Check

​Downstream Validation

​Change Migration Strategy

​Adding Optional Fields

​Deprecating Fields

​Renaming Fields

​Package Configuration

​Exports

​Files

​Related Documentation

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