How Can I Link Only FirebaseMessaging via Swift Package Manager in Xcode?

Below is an explanation of what’s happening with Swift Package Manager (SPM) and Firebase:

How SPM Works with Firebase

When using SPM with Firebase, you add the entire Firebase iOS SDK repository as a package. This package contains many modules (like FirebaseDatabase, FirebaseStorage, FirebaseMessaging, etc.). Even though all these modules are downloaded, you control which ones your app actually links against.

What It Means for Your App

• Downloaded vs. Linked: SPM downloads the whole repository, but only the modules that you add as a dependency in your target will be linked into your app. In your Xcode project, you add a package dependency and select the product (e.g., FirebaseMessaging) for your target.
• Unused Modules: Even though the package contains additional Firebase products, if you don’t import or link them in your code or in your target’s settings, they won’t be used in your app binary.

Why You See Everything

The Xcode UI for adding packages shows all available products from the Firebase repository. You might see a list of many Firebase modules even if you only need FirebaseMessaging. This is expected behavior with SPM and does not mean your app will include the extra code. It’s simply a way of managing dependencies. If you need more granular control on what to download and compile, you could manually define your Package.swift file, but most projects stick with the Xcode integration.

Alternative

• CocoaPods: If you prefer to add only the specific pods you want (e.g., just FirebaseMessaging), you can use CocoaPods. This gives you a more “modular” selection during dependency installation.
• Manual Linking: With SPM, you just need to ensure that your target only links to FirebaseMessaging. Only the APIs you import from FirebaseMessaging are used in your project.

Summary

This is normal behavior. With SPM, you add the entire Firebase repository, but you control which Firebase modules your target uses. As long as you only import and link FirebaseMessaging, the extra modules won’t affect your app.