Safely modifies Xcode projects (.pbxproj) to add Swift Packages and link files. Use this skill whenever an iOS project needs dependencies installed (e.g. Firebase, Alamofire).
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SKILL.md
xcode-project-setup
Safely modifies Xcode projects (.pbxproj) to add Swift Packages and link files. Use this skill whenever an iOS project needs dependencies installed (e.g. Firebase, Alamofire).
compatibility
Requires Swift to be installed locally and macOS environment.
metadata.category
ApplicationDevelopment
Xcode Project Setup
⛔️ CRITICAL RULES & ENVIRONMENT CHECKS
Before performing any Xcode setup or file manipulation, you MUST adhere to
the following rules. A hefty fee will be applied if you violate them.
You are strictly forbidden from using Ruby, Rails, or any Ruby gems
(including the xcodeproj gem). Under no circumstances may you write or execute
Ruby scripts.
2. Modern Xcode Folder Synchronization
Modern Xcode projects support folder synchronization. When adding new source
code (.swift) or resource files, simply write them to the correct directory on
disk. They will be automatically included in the Xcode project. Never manually
modify the .pbxproj file to add files.
3. Allowed Scripting Languages
If you absolutely must write a script to manipulate the project environment
(e.g., configuring SPM packages beyond what the provided xcode_spm_setup
script does), you must use Swift. Only as an absolute last resort, if Swift
is completely unviable, may you use Node.js or TypeScript.
4. Toolchain Verification
Because this skill relies entirely on a native Swift script, you must verify the
environment:
Run swift --version before proceeding.
If the Swift command is not found, you must stop and recommend the user
install the Swift toolchain (e.g., via xcode-select --install on macOS), or
ask if you can attempt to install it for them. Do not attempt to proceed
without Swift.
5. Mandatory Linker Flags for Static Frameworks (Firebase)
When setting up SPM dependencies that heavily rely on internal Objective-C
categories and +load methods (such as the Firebase iOS SDK suite), the Apple
linker will aggressively strip these methods out if they are linked statically.
This causes fatal runtime crashes (e.g.,
FirebaseAuth/Auth.swift:167: Fatal error: Unexpectedly found nil).
The provided xcode_spm_setup Swift script automatically injects the -ObjC
flag to OTHER_LDFLAGS when adding Firebase products. However, you should
still verify it is present in the build settings if you encounter issues.
Failing to include this flag when adding Firebase dependencies is a critical
error.
Empty Directory Workflow
If you are asked to build an iOS app or configure Xcode dependencies but no
.xcodeproj or .xcworkspace exists, you MUST ask the user to create the
project first:
"No Xcode project found in this directory. Please create an empty Xcode
project manually and let me know when you are ready to proceed."
Wait for the user to confirm they have created the .xcodeproj via Xcode, then
proceed with the Standard Xcode Workflow below.
Standard Xcode Workflow
Do not use raw text parsing, sed, or Ruby scripts to modify .pbxproj files
directly.
Instead, execute the Swift configuration package bundled with this skill
(scripts/xcode_spm_setup) to securely install SPM packages and link optional
config files (like GoogleService-Info.plist).
CRITICAL: Always Use Latest SDK Version
To ensure access to the latest features and security fixes, always use the most
recent version of the Firebase iOS SDK. Check for the latest release version at
https://github.com/firebase/firebase-ios-sdk/releases.
Use the most recent version number (e.g., 11.x.y) in your commands instead
of hardcoded placeholders.
Understanding the Script's Actions
When adding a Swift Package to an Xcode project, two distinct steps must occur:
Adding the package repository dependency (e.g.,
https://github.com/Alamofire/Alamofire).
Selecting the target (e.g., MyApp), navigating to General > Frameworks,
Libraries, and Embedded Content, and hitting the + button to explicitly
link the specific product modules (e.g., Alamofire).
The provided xcode_spm_setup Swift script automatically handles BOTH of
these steps for you. By passing the list of modules as arguments, it safely
injects the package dependency and automatically wires those modules to the main
target's Frameworks build phase. You do not need to do any manual linking.
Usage
Locate the package path: Find the absolute path to this skill's
scripts/xcode_spm_setup directory on disk.
Execute: Run the native swift run command using the signature below:
swift run --package-path <PATH_TO_SKILL>/scripts/xcode_spm_setup xcode_spm_setup <ProjectPath.xcodeproj> <RepoURL> <VersionRequirement> [--plist <Optional/Path/To/Config.plist>] <Product1> [Product2 ...]
Example 1: Generic Package (e.g., Alamofire)
Adding Alamofire to a standard Xcode project. Notice there is no --plist flag.
swift run --package-path /Users/foo/.agents/skills/xcode-project-setup/scripts/xcode_spm_setup xcode_spm_setup MyApp.xcodeproj https://github.com/Alamofire/Alamofire 5.8.1 Alamofire
Example 2: Firebase (Requires Plist)
Adding Firebase and linking the GoogleService-Info.plist to the resources
build phase automatically. Note: Replace 11.0.0 with the actual latest
version from
the releases page.
swift run --package-path /Users/foo/.agents/skills/xcode-project-setup/scripts/xcode_spm_setup xcode_spm_setup MyApp.xcodeproj https://github.com/firebase/firebase-ios-sdk 11.0.0 --plist MyApp/GoogleService-Info.plist FirebaseCore FirebaseAuth FirebaseFirestore
Note: The script is idempotent. It will automatically skip linking files or
packages that are already present in the project.
