Authored by Patrick Mitchell

Today we’re announcing the release of Swift support for generated SDKs in the Buf Schema Registry (BSR)! Swift engineers no longer need to manage a Protobuf toolchain or generate code locally—they can now download pre-packaged generated code for their Protobuf schemas from the BSR using Swift Package Manager and Xcode. These packages are automatically made available when schema changes are pushed to the BSR.

Swift package support complements our existing Go, JavaScript/TypeScript, and Java/Kotlin packages, enabling clients across all frontend and mobile platforms to consume generated packages from Protobuf schemas using their native dependency managers.

We've updated each BSR module’s Generated SDKs tab with instructions on how to get started with remote Swift packages using either Xcode or Swift Package Manager. You can also find instructions and more details in our documentation.

Using generated SDKs with Xcode

As an example, let's take an existing Swift project that makes use of locally-generated code and update it to consume the remote Swift package for a Protobuf module in the BSR.

To get started, clone the connect-swift repository:

$ git clone git@github.com:connectrpc/connect-swift.git

Then, open the example app’s Xcode project:

$ open Examples/ElizaSwiftPackageApp/ElizaSwiftPackageApp.xcodeproj

Now that we have the project open, let’s delete the locally generated code from the project, which we’ll then replace with a generated SDK. Remove the following files from the GeneratedSources directory:

ElizaSwiftPackageApp/ElizaSharedSources/GeneratedSources/eliza.pb.swift
ElizaSwiftPackageApp/ElizaSharedSources/GeneratedSources/eliza.connect.swift

Next, navigate to the Generated SDKs tab for the Eliza repository in the BSR and select Swift from the language drop-down. Then select Xcode in the tab view and copy the provided URL for connectrpc/swift:

Then, navigate to the Xcode project and select File > Add Packages...:

In the popup window, click into the Search or Enter Package URL text field in the top right and paste the URL.

Next, point the dependency at the main branch. Buf produces a separate git URL for each BSR commit due to versioning requirements, so this will always be stable.

Alternatively, you can also specify the package version explicitly as an Exact Version:

A popup will prompt you to link the package’s product (the generated library) to your app. There will only be one option—ensure it’s selected and click Add Package to confirm the package addition, which will automatically add any transitive dependencies:

Navigate to the MenuView.swift file and add the import statement for the generated module for connect-swift:

import Connectrpc_Eliza_Connectrpc_Swift

Navigate to MessagingViewModel.swift and add the import statements for both the generated Connect code and the SwiftProtobuf types:

import Connectrpc_Eliza_Apple_Swift // Transitive dependency of Connectrpc_Eliza_Connectrpc_Swift
import Connectrpc_Eliza_Connectrpc_Swift

You should be able to build and run the app! Future commits pushed to the Eliza repository in the BSR will be available as Swift packages automatically, and there is no longer a need to manage a local Protobuf toolchain or generate code manually.

Using generated SDKs with SPM (Swift Package Manager)

Buf’s remote Swift packages also work with Swift Package Manager and Package.swift files. For details on how to use generated SDKs with SPM, take a look at our documentation.

Where to go from here

Head over to our documentation to get started with generated SDKs for Swift, and check out connect-swift if you aren’t already using it for your Swift RPCs! If you’re new to generated SDKs, documentation is also available for each of our other supported package managers: Go packages, NPM, and Maven. As always, we’d love to hear from you—feedback and questions are welcome on the Buf Slack!