Xcode MCP Usage Guidelines for Agents

---
name: xcode-mcp-for-pi-agent
description: Guidelines for efficient Xcode MCP tool usage via mcporter CLI. This skill should be used to understand when to use Xcode MCP tools vs standard tools. Xcode MCP consumes many tokens - use only for build, test, simulator, preview, and SourceKit diagnostics. Never use for file read/write/grep operations. Use this skill whenever working with Xcode projects, iOS/macOS builds, SwiftUI previews, or Apple platform development.
---

# Xcode MCP Usage Guidelines

Xcode MCP tools are accessed via `mcporter` CLI, which bridges MCP servers to standard command-line tools. This skill defines when to use Xcode MCP and when to prefer standard tools.

## Setup

Xcode MCP must be configured in `~/.mcporter/mcporter.json`:

```json
{
  "mcpServers": {
    "xcode": {
      "command": "xcrun",
      "args": ["mcpbridge"],
      "env": {}
    }
  }
}
```

Verify the connection:
```bash
mcporter list xcode
```

---

## Calling Tools

All Xcode MCP tools are called via mcporter:

```bash
# List available tools
mcporter list xcode

# Call a tool with key:value args
mcporter call xcode.<tool_name> param1:value1 param2:value2

# Call with function-call syntax
mcporter call 'xcode.<tool_name>(param1: "value1", param2: "value2")'
```

---

## Complete Xcode MCP Tools Reference

### Window & Project Management
| Tool | mcporter call | Token Cost |
|------|---------------|------------|
| List open Xcode windows (get tabIdentifier) | `mcporter call xcode.XcodeListWindows` | Low ✓ |

### Build Operations
| Tool | mcporter call | Token Cost |
|------|---------------|------------|
| Build the Xcode project | `mcporter call xcode.BuildProject` | Medium ✓ |
| Get build log with errors/warnings | `mcporter call xcode.GetBuildLog` | Medium ✓ |
| List issues in Issue Navigator | `mcporter call xcode.XcodeListNavigatorIssues` | Low ✓ |

### Testing
| Tool | mcporter call | Token Cost |
|------|---------------|------------|
| Get available tests from test plan | `mcporter call xcode.GetTestList` | Low ✓ |
| Run all tests | `mcporter call xcode.RunAllTests` | Medium |
| Run specific tests (preferred) | `mcporter call xcode.RunSomeTests` | Medium ✓ |

### Preview & Execution
| Tool | mcporter call | Token Cost |
|------|---------------|------------|
| Render SwiftUI Preview snapshot | `mcporter call xcode.RenderPreview` | Medium ✓ |
| Execute code snippet in file context | `mcporter call xcode.ExecuteSnippet` | Medium ✓ |

### Diagnostics
| Tool | mcporter call | Token Cost |
|------|---------------|------------|
| Get compiler diagnostics for specific file | `mcporter call xcode.XcodeRefreshCodeIssuesInFile` | Low ✓ |
| Get SourceKit diagnostics (all open files) | `mcporter call xcode.getDiagnostics` | Low ✓ |

### Documentation
| Tool | mcporter call | Token Cost |
|------|---------------|------------|
| Search Apple Developer Documentation | `mcporter call xcode.DocumentationSearch` | Low ✓ |

### File Operations (HIGH TOKEN - NEVER USE)
| MCP Tool | Use Instead | Why |
|----------|-------------|-----|
| `xcode.XcodeRead` | `Read` tool / `cat` | High token consumption |
| `xcode.XcodeWrite` | `Write` tool | High token consumption |
| `xcode.XcodeUpdate` | `Edit` tool | High token consumption |
| `xcode.XcodeGrep` | `rg` / `grep` | High token consumption |
| `xcode.XcodeGlob` | `find` / `glob` | High token consumption |
| `xcode.XcodeLS` | `ls` command | High token consumption |
| `xcode.XcodeRM` | `rm` command | High token consumption |
| `xcode.XcodeMakeDir` | `mkdir` command | High token consumption |
| `xcode.XcodeMV` | `mv` command | High token consumption |

---

## Recommended Workflows

### 1. Code Change & Build Flow
```
1. Search code      → rg "pattern" --type swift
2. Read file        → Read tool / cat
3. Edit file        → Edit tool
4. Syntax check     → mcporter call xcode.getDiagnostics
5. Build            → mcporter call xcode.BuildProject
6. Check errors     → mcporter call xcode.GetBuildLog (if build fails)
```

### 2. Test Writing & Running Flow
```
1. Read test file   → Read tool / cat
2. Write/edit test  → Edit tool
3. Get test list    → mcporter call xcode.GetTestList
4. Run tests        → mcporter call xcode.RunSomeTests (specific tests)
5. Check results    → Review test output
```

### 3. SwiftUI Preview Flow
```
1. Edit view        → Edit tool
2. Render preview   → mcporter call xcode.RenderPreview
3. Iterate          → Repeat as needed
```

### 4. Debug Flow
```
1. Check diagnostics → mcporter call xcode.getDiagnostics
2. Build project     → mcporter call xcode.BuildProject
3. Get build log     → mcporter call xcode.GetBuildLog severity:error
4. Fix issues        → Edit tool
5. Rebuild           → mcporter call xcode.BuildProject
```

### 5. Documentation Search
```
1. Search docs       → mcporter call xcode.DocumentationSearch query:"SwiftUI NavigationStack"
2. Review results    → Use information in implementation
```

---

## Fallback Commands (When MCP or mcporter Unavailable)

If Xcode MCP is disconnected, mcporter is not installed, or the connection fails, use these xcodebuild commands directly:

### Build Commands
```bash
# Debug build (simulator) - replace <SchemeName> with your project's scheme
xcodebuild -scheme <SchemeName> -configuration Debug -sdk iphonesimulator build

# Release build (device)
xcodebuild -scheme <SchemeName> -configuration Release -sdk iphoneos build

# Build with workspace (for CocoaPods projects)
xcodebuild -workspace <ProjectName>.xcworkspace -scheme <SchemeName> -configuration Debug -sdk iphonesimulator build

# Build with project file
xcodebuild -project <ProjectName>.xcodeproj -scheme <SchemeName> -configuration Debug -sdk iphonesimulator build

# List available schemes
xcodebuild -list
```

### Test Commands
```bash
# Run all tests
xcodebuild test -scheme <SchemeName> -sdk iphonesimulator \
  -destination "platform=iOS Simulator,name=iPhone 16" \
  -configuration Debug

# Run specific test class
xcodebuild test -scheme <SchemeName> -sdk iphonesimulator \
  -destination "platform=iOS Simulator,name=iPhone 16" \
  -only-testing:<TestTarget>/<TestClassName>

# Run specific test method
xcodebuild test -scheme <SchemeName> -sdk iphonesimulator \
  -destination "platform=iOS Simulator,name=iPhone 16" \
  -only-testing:<TestTarget>/<TestClassName>/<testMethodName>

# Run with code coverage
xcodebuild test -scheme <SchemeName> -sdk iphonesimulator \
  -configuration Debug -enableCodeCoverage YES

# List available simulators
xcrun simctl list devices available
```

### Clean Build
```bash
xcodebuild clean -scheme <SchemeName>
```

---

## Quick Reference

### USE mcporter + Xcode MCP For:
- ✅ `xcode.BuildProject` — Building
- ✅ `xcode.GetBuildLog` — Build errors
- ✅ `xcode.RunSomeTests` — Running specific tests
- ✅ `xcode.GetTestList` — Listing tests
- ✅ `xcode.RenderPreview` — SwiftUI previews
- ✅ `xcode.ExecuteSnippet` — Code execution
- ✅ `xcode.DocumentationSearch` — Apple docs
- ✅ `xcode.XcodeListWindows` — Get tabIdentifier
- ✅ `xcode.getDiagnostics` — SourceKit errors

### NEVER USE Xcode MCP For:
- ❌ `xcode.XcodeRead` → Use `Read` tool / `cat`
- ❌ `xcode.XcodeWrite` → Use `Write` tool
- ❌ `xcode.XcodeUpdate` → Use `Edit` tool
- ❌ `xcode.XcodeGrep` → Use `rg` or `grep`
- ❌ `xcode.XcodeGlob` → Use `find` / `glob`
- ❌ `xcode.XcodeLS` → Use `ls` command
- ❌ File operations → Use standard tools

---

## Token Efficiency Summary

| Operation | Best Choice | Token Impact |
|-----------|-------------|--------------|
| Quick syntax check | `mcporter call xcode.getDiagnostics` | 🟢 Low |
| Full build | `mcporter call xcode.BuildProject` | 🟡 Medium |
| Run specific tests | `mcporter call xcode.RunSomeTests` | 🟡 Medium |
| Run all tests | `mcporter call xcode.RunAllTests` | 🟠 High |
| Read file | `Read` tool / `cat` | 🟢 Low |
| Edit file | `Edit` tool | 🟢 Low |
| Search code | `rg` / `grep` | 🟢 Low |
| List files | `ls` / `find` | 🟢 Low |