---

name: xcsift description: Use xcsift for Swift and Xcode build output. Activate when running swift build, swift test, or xcodebuild commands. Pipe output through xcsift for structured TOON format optimized for LLM consumption.

xcsift - Xcode Build Output Formatter

xcsift is a Swift command-line tool that parses and formats xcodebuild/SPM output for coding agents. It transforms verbose Xcode build output into token-efficient TOON format optimized for machine readability.

When to Use

Use xcsift when running Swift or Xcode build commands:

• xcodebuild build
• xcodebuild test
• swift build
• swift test

Usage Pattern

Always pipe build output through xcsift with stderr redirected:

Copy# Basic usage
xcodebuild build 2>&1 | xcsift -f toon
swift build 2>&1 | xcsift -f toon

# With warnings
xcodebuild build 2>&1 | xcsift -f toon -w

# With code coverage
swift test --enable-code-coverage 2>&1 | xcsift -f toon -c
xcodebuild test -enableCodeCoverage YES 2>&1 | xcsift -f toon -c

# With executable targets
xcodebuild build 2>&1 | xcsift -f toon -e

# Strict CI mode (fail on warnings)
xcodebuild build 2>&1 | xcsift -f toon -W -E

Key Flags

Output Format

TOON format provides structured output optimized for LLMs:

Copystatus: failed
summary:
  errors: 1
  warnings: 3
errors[1]{file,line,message}:
  main.swift,15,"use of undeclared identifier"
warnings[3]{file,line,message}:
  Parser.swift,20,"unused variable"

Important Notes

• Always use 2>&1 to capture stderr (where compiler errors are written)
• TOON format reduces tokens by 30-60% compared to raw xcodebuild output
• When running build commands, always add | xcsift -f toon to the end

Example Workflow

1. Build the project:

   Copyswift build 2>&1 | xcsift -f toon
   

2. If build fails, analyze the structured error output

3. Run tests with coverage:

   Copyswift test --enable-code-coverage 2>&1 | xcsift -f toon -c
   

4. For CI pipelines, use strict mode:

   Copyxcodebuild build 2>&1 | xcsift -f toon -W -E