MCP Setup

MCP Setup

Four MCPs give Claude Code full access to your design files, Apple documentation, the Xcode build system, and visual preview rendering. Set these up once and every project benefits.

The Stack

Setup Instructions

1. Figma MCP

You likely already have this connected. If not:

claude mcp add figma -- npx -y figma-developer-mcp --figma-api-key YOUR_KEY

Or connect via OAuth in Claude Code settings. This lets Claude Code read frame layouts, text content, colors, spacing, and component hierarchy directly from your Figma files.

2. Sosumi (Apple Developer Documentation)

This is critical. Apple's docs are locked behind JavaScript, which means Claude Code can't read them by default. Sosumi translates Apple Developer docs, Human Interface Guidelines, and WWDC sessions into AI-friendly Markdown.

claude mcp add sosumi -- npx -y mcp-remote https://sosumi.ai/mcp

Or as a Claude Code skill (available in every project):

mkdir -p ~/.claude/skills/sosumi
curl -o ~/.claude/skills/sosumi/SKILL.md https://sosumi.ai/SKILL.md

What this enables:

• Claude Code can look up any SwiftUI modifier, any HIG guideline
• When building Liquid Glass effects, it reads the actual iOS 26 docs
• When you say "use the correct presentation style," it checks HIG
• WWDC session transcripts are searchable for implementation guidance

3. XcodeBuildMCP (Build System)

This gives Claude Code 59 tools for building, testing, and deploying without Xcode open.

claude mcp add XcodeBuildMCP \
  -s user \
  -e XCODEBUILDMCP_SENTRY_DISABLED=true \
  -- npx -y xcodebuildmcp@latest mcp

The -s user flag makes it global (available in every project).

What this enables:

• build_sim_name_proj — Build for simulator
• test_sim_name_proj — Run tests
• clean — Clean build folder
• Simulator management, device deployment, LLDB debugging

4. Apple's Xcode MCP Bridge (Visual Previews)

Requires Xcode 26.3+. This bridges into a running Xcode instance via XPC.

claude mcp add --transport stdio xcode -- xcrun mcpbridge

Important: Xcode must be running for this to work. XcodeBuildMCP works standalone; this one requires Xcode open.

What this enables:

• RenderPreview — Captures SwiftUI preview screenshots. Claude Code can SEE what it built.
• DocumentationSearch — Semantic search across Apple docs + WWDC transcripts
• ExecuteSnippet — Runs Swift code in a REPL-like context
• Build, diagnostics, file operations within Xcode

Verification

After setup, verify all MCPs are connected:

claude mcp list

You should see: figma, sosumi, XcodeBuildMCP, and xcode.

Test each one:

• "Search Apple docs for presentationDetents" (Sosumi)
• "Build the project for iPhone 16 simulator" (XcodeBuildMCP)
• "Render a preview of ContentView" (Xcode MCP Bridge)
• "Read the frame at [Figma URL]" (Figma MCP)

How They Work Together

The build loop with all four MCPs:

1. You describe what a screen should do
2. Claude Code reads the Figma frame (Figma MCP)
3. Claude Code checks the correct SwiftUI APIs (Sosumi)
4. Claude Code builds the screen
5. Claude Code builds the project (XcodeBuildMCP)
6. Claude Code renders a preview (Xcode MCP Bridge)
7. Claude Code compares preview to Figma design
8. Claude Code iterates on its own until it looks right
9. You review the final result

Steps 2-8 happen without your intervention. You describe and review. Claude Code handles the middle.

When MCPs Overlap

XcodeBuildMCP and the Xcode MCP Bridge both can build projects. The difference:

• XcodeBuildMCP works without Xcode running. Use for CI-style builds and tests.
• Xcode MCP Bridge requires Xcode running. Use for previews and visual verification.

Sosumi and the Xcode MCP Bridge both search documentation. The difference:

• Sosumi returns full markdown documentation, HIG pages, and WWDC transcripts.
• Xcode Bridge DocumentationSearch uses Apple's semantic search with MLX embeddings. Better for "find me something related to X."

Both are useful. Don't choose one over the other. Let Claude Code pick the right tool.

Troubleshooting

Sosumi returns empty results: Check your internet connection. Sosumi is a remote service.

XcodeBuildMCP can't find the project: Make sure you're in the project directory. Run ls *.xcodeproj to confirm.

Xcode MCP Bridge won't connect: Xcode must be running. Open Xcode, then try again. Also verify Xcode 26.3+ is installed.

Figma MCP can't read frames: Check your API key. Or if using OAuth, re-authenticate in Claude Code settings.