sourcekit-bazel-bsp is a Build Server Protocol implementation that serves as a bridge between sourcekit-lsp (Swift's official Language Server Protocol) and your Bazel-based code, giving you the power to break free from the IDE side of Xcode and develop for Apple platforms like iOS in any IDE that has support for LSPs, such as Cursor and VSCode.
Important
sourcekit-bazel-bsp is designed specifically for projects that use the Bazel build system under the hood. It will not work for regular Xcode projects. For Xcode, check out projects like xcode-build-server (unrelated to this project and Spotify).
Warning
sourcekit-bazel-bsp is currently in very early stages of development and is not ready for production usage. It currently works only at a limited capacity and is missing several important features.
- All of the usual indexing features such as code completion, jump to definition, error annotations and so on, for both Swift and Obj-C (via the official sourcekit-lsp)
- (Cursor / VSCode): Building and launching, all from within the IDE and directly via Bazel (no project generation required!)
- (Cursor / VSCode): Full
lldbintegration, allowing debugging from within the IDE just like Xcode (via lldb-dap, automatically provided by the official Swift extension) - (Cursor / VSCode): Simulator selection from within the IDE
- (Cursor / VSCode): Automatic generation of build, launch, and debug tasks
- (Cursor / VSCode): Test explorer & ability to run tests from within the IDE by clicking the tests individually, similarly to Xcode
- Automatic index and build graph updates when adding / deleting files and targets (in other words, allowing the user to make heavy changes to the project without needing to restart the IDE)
- Swift 6.1+ toolchain (equivalent to Xcode 16.4+)
- Note that even though sourcekit-bazel-bsp itself is completely detached from Xcode, you will still need to have Xcode installed on your machine to do any sort of actual Apple development. This is because installing Xcode is currently the only way to get access to and manage the platform toolchains, so even though this tool allows you to break free from the Xcode IDE itself, you still need to have it around for toolchain reasons. In order to completely avoid Xcode, we would need Apple to detach it from the toolchains and all their related tooling.
- Make sure your Bazel project is using compatible versions of all iOS-related Bazel rulesets and is configured to generate Swift/Obj-C indexing data and debug symbols, either by default or under a specific config.
- Detailed information on this is currently WIP, but you can currently check out the example project for an example.
- Download and install the official Swift extension for Cursor / VSCode.
- Copy the .bsp/ folder on this repository to the root of the repository you'd like to use this tool for.
- Edit the
argvfields in.bsp/config.jsonto match the details for your app / setup. You can see all available options by runningsourcekit-bazel-bsp serve --help. - On Cursor / VSCode, open a workspace containing the repository in question.
- On the settings page for the Swift extension, enable
SourceKit-LSP: Background Indexingat the workspace level. It has to be workspace settings; this specific setting is not supported at the folder level. - Reload your workspace (
Cmd+Shift+P -> Reload Window)
After following these steps, the SourceKit Language Server output tab (Cmd+Shift+U) should show up when opening Swift or Obj-C files, and indexing-related actions will start popping up at the bottom of the IDE after a while alongside a new SourceKit-LSP: Indexing output tab when working with those files.
If you experience any trouble trying to get it to work, check out the Example/ folder for a test project with a pre-configured Bazel and .bsp setup. The Troubleshooting section below also contains instructions on how to debug sourcekit-bazel-bsp.
The setup instructions depend on how the IDE integrates with LSPs. You should then search for instructions on how to install sourcekit-lsp on your IDE of choice and enable background indexing. After that, follow the .bsp/ related steps from the above instructions. Keep in mind that this since project is developed specifically with Cursor / VSCode in mind, we cannot say how well sourcekit-bazel-bsp would work with other IDEs.
sourcekit-bazel-bsp uses Apple's OSLog infrastructure under the hood. To see the tool's logs, run log stream --process sourcekit-bazel-bsp --debug on a terminal session.
By default, most logs will be redacted for privacy reasons, but you may want to see them for debug and development reasons. To enable extended logging and expose those logs, install the configuration profile at as described here You will then able to see the redacted logs.
If you wish for the logs to become redacted again, you can remove the configuration profile as described here.
Since sourcekit-bazel-bsp is initialized from within sourcekit-lsp, debugging it requires you to start a lldb session in advance. You can do it with the following command: lldb --attach-name sourcekit-bazel-bsp --wait-for
Once the lldb session is initialized, triggering the initialization of the Swift extension on your IDE of choice (e.g. opening a Swift file in VSCode) should eventually cause lldb to start a debugging session.