Firebase Data Connect for Swift

Connect your Swift & SwiftUI apps directly to a managed Google CloudSQL (PostgreSQL) database.

This repository contains the official open-source Swift SDK for Firebase Data Connect, a service that lets you build modern, data-driven applications on Apple platforms (iOS, macOS, etc.) with the power and scalability of a SQL database.

This SDK is perfect for those:

• Who need a robust SQL database for their app but want to avoid writing and managing a separate backend.
• Looking for a type-safe, async-first library to integrate a PostgreSQL database into their applications.

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✨ Why Use Firebase Data Connect?

• Use power of SQL: Get the power of a managed PostgreSQL database without the hassle of managing servers. Focus on your app's frontend experience.
• Type-Safe & Modern Swift: Interact with your database using a strongly-typed, auto-generated Swift SDK. It's built with modern async/await for clean, concurrent code.
• Built for SwiftUI: @Observable Queries automatically update your SwiftUI views when data changes, making it incredibly simple to build reactive UIs.
• Full CRUD Operations: Define your data models and operations using GraphQL, and Data Connect generates the Swift code to query, insert, update, and delete data.
• Local Emulator: Develop and test your entire application locally with the FDC emulator for a fast and efficient development cycle.

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🚀 Getting Started

This guide will walk you through setting up a new iOS (or other Apple platform) project with Firebase Data Connect.

Prerequisites

• Xcode 16.2 or later
• iOS 15.0 or later
• A Google account for the FDC tools

Step 1: Get the SDK & Tools

First, clone this repository to your local machine. This contains both the core SDK and the command-line tools needed for code generation.

git clone https://github.com/firebase/data-connect-ios-sdk.git

Step 2: Configure Your Xcode Project

1. Add Local Package: In Xcode, open your app project and navigate to File > Add Package Dependencies....
2. In the package prompt, click "Add Local..." and select the data-connect-ios-sdk folder you just cloned.
3. Add the FirebaseDataConnect library to your app's primary target.

Step 3: Run the Data Connect Tools

The Data Connect tools run on your Mac to provide a local development emulator and code generation service.

1. Add New Scheme: In Xcode's scheme menu, select New Scheme.... Choose the Start FDC Tools target and click OK.
2. Set Working Directory: Edit the new Start FDC Tools scheme. Go to Run > Options and check "Use custom working directory". Set this to the root folder of your Xcode project.
3. Run the Tools: Select the Start FDC Tools scheme with My Mac as the destination and click Run (▶). This will open the FDC tools in your web browser.

Step 4: Generate Your Type-Safe Swift SDK

The tools will generate a custom Swift package based on your database schema.

1. Sign In: In the FDC tools web UI, sign in with your Google account.

2. Start Emulator: Click the button to start the local FDC Emulator.

3. Generate Code: The tools will automatically detect the GraphQL schema (.gql files) in your project's dataconnect subfolder and generate a new Swift package in a dataconnect-generated folder.
4. Reference cloned SDK: From the FDC tools, modify the dataconnect/default/connector.yaml file to specify the location of the cloned data-connect-ios-sdk by updating the coreSdkPackageLocation property.
5. Add Generated SDK to Xcode: Back in Xcode, add another local package (File > Add Package Dependencies... > Add Local...). This time, select the new Swift package inside the dataconnect-generated folder. Add this new library (e.g., ItemData) to your app target.
6. Add GoogleService-Info.plist to Xcode: From Xcode. add a file to your project (File > Add Files to ...). Select the file GoogleService-Info.plist thats in your Xcode project folder and add it as a Reference.

Step 5: Initialize Firebase in Your App

In your main app file (the one with @main), initialize Firebase and configure Data Connect to use the local emulator.

// MyApp.swift
import SwiftUI
import Firebase
import FirebaseDataConnect
import ItemData // The name of your generated SDK package

@main
struct MyApp: App {
  init() {
    // 1. Configure Firebase
    FirebaseApp.configure()

    // 2. Point Data Connect to the local emulator
    DataConnect.itemsConnector.useEmulator()
  }

  var body: some Scene {
    WindowGroup {
      ContentView()
    }
  }
}

Step 6: Execute a Mutation (Create Data)

Now you can write data to the database from any SwiftUI view.

// ContentView.swift
import SwiftUI
import FirebaseDataConnect
import ItemData

struct ContentView: View {
  var body: some View {
    VStack {
      Button("Create Item") {
        Task {
          do {
            let itemID = UUID()
            let itemName = "Item-\(Int.random(in: 1...1000))"
            let result = try await DataConnect.itemsConnector.createItemMutation.execute(id: itemID, name: itemName)
            print("✅ Successfully created item: \(result)")
          } catch {
            print("❌ Error creating item: \(error)")
          }
        }
      }
    }
  }
}

Note: You may need to enable App Sandbox -> Outgoing Connections (Client) for your Xcode app target to run it from iPhone simulator.

Step 7: Execute a Query (Read & Display Data)

Use a QueryRef to fetch data and automatically bind it to your SwiftUI view.

// ContentView.swift
import SwiftUI
import FirebaseDataConnect
import ItemData

struct ContentView: View {
  // A reference to our query
  @State var itemsQueryRef = DataConnect.itemsConnector.listItemsQuery.ref()

  var body: some View {
    VStack {
      // (Create Button from previous step)

      // The List will update when the query data changes
      if let items = itemsQueryRef.data?.items {
        List(items) { item in
          Text(item.name)
        }
      }

      Button("Refresh List") {
        Task {
          // Manually refetch the data
          _ = try? await itemsQueryRef.execute()
        }
      }
    }
    .task {
        // Fetch initial data when the view appears
        _ = await itemsQueryRef.execute()
    }
  }
}

That's it! You've connected your app to a local SQL database, created a new record, and displayed a list of records in your UI.

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📚 Next Steps

• Stretch Goal: Modify the schema.gql, queries.gql and mutations.gql to add a price field to the Item entity. The generated SDK should get automatically created. Hint: See comments in the files.
• Schema Design: Try creating your own Schema and Queries. Learn more about designing schemas, queries, and mutations in the official documentation.
• Codelab: Follow our detailed Firebase Data Connect for iOS Codelab.
• Sample App: Explore a complete sample application, FriendlyFlix, to see more advanced usage patterns.
• Go to Production: When you're ready to deploy, visit the Firebase Console to connect to a live CloudSQL (PostgreSQL) instance.

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🤝 Contributing

Please see the Contributing guide for more information.

📄 License

This repository is licensed under the Apache License, version 2.0. Your use of Firebase is governed by the Terms of Service for Firebase Services.