Cursor treats Swift as plain text until you wire up language intelligence. This guide shows how to enable Swift autocomplete, diagnostics, and go-to-definition with SourceKit-LSP and a build server.
Because Cursor is a fork of VS Code, it has no built-in understanding of Swift — unlike Xcode, which bundles full Swift intelligence. To get autocomplete, inline errors, hover documentation, and jump-to-definition, you connect Cursor to SourceKit-LSP, the language server that ships with Apple's Swift toolchain. Note the distinction: Cursor's AI features (Tab, chat, Composer) work on Swift files without any of this, because they read raw text. What setup unlocks is the precise, non-AI language intelligence that makes editing Swift comfortable and that, in turn, gives the AI better signal. Budget about fifteen to twenty minutes.
SourceKit-LSP comes with the Swift toolchain. If you have Xcode installed, you already have a toolchain; confirm the command-line tools are selected by running 'xcode-select --install' if needed, or point at Xcode's tools with 'sudo xcode-select -s /Applications/Xcode.app'. You can verify Swift is available by running 'swift --version' in a terminal. For projects that are pure Swift Package Manager packages, this toolchain alone is enough for the language server to work. For full iOS app projects built around an .xcodeproj or .xcworkspace, you will also need the build-server step covered below so the language server can resolve UIKit, SwiftUI, and your app's modules.
Open the Extensions panel in Cursor (Cmd+Shift+X) and search for the official Swift extension maintained by the Swift project. Install it. This extension launches SourceKit-LSP and provides Swift syntax features, diagnostics, and integration with the package manager. Because Cursor uses the Open VSX registry rather than the Microsoft Marketplace, most popular extensions are available, but if you cannot find one you can install it from a downloaded .vsix file via the Extensions panel's overflow menu. After installing, reload the window (Cmd+Shift+P, then 'Reload Window') so the language server starts cleanly.
For an iOS app project, SourceKit-LSP needs to know your build settings. The community-standard tool is xcode-build-server, which generates a buildServer.json file that the language server reads. Install it (for example via Homebrew with 'brew install xcode-build-server'), then from your project root run the command that captures your build settings — typically by piping an 'xcodebuild' invocation for your scheme through xcode-build-server's config command. This produces buildServer.json alongside your project. With that file present, SourceKit-LSP can resolve framework imports and your own types, and autocomplete starts behaving like Xcode's. Rebuild in Xcode once after generating it so the index store is populated.
To keep AI suggestions idiomatic, add project rules. Create a .cursorrules file (or a .cursor/rules directory) at your project root and state your conventions: target iOS version, SwiftUI versus UIKit preference, concurrency style (async/await over completion handlers), naming conventions, and architecture (for example MVVM with observable models). Cursor feeds these rules into its AI context, so generated code matches your codebase instead of generic examples. This single file dramatically improves the quality and consistency of Composer and Cmd+K output, and it is the highest-leverage five minutes of configuration you can do.
Open a Swift file and confirm three things: typing a type name offers completions with correct signatures, hovering a symbol shows its documentation, and an intentional error (such as referencing an undefined variable) produces a red diagnostic inline. If completions are missing, check that the Swift extension is enabled, that buildServer.json exists for app projects, and that you reloaded the window after setup. If diagnostics never appear, open the Output panel and select the SourceKit-LSP channel to read its logs — they usually name the exact problem, such as a missing toolchain path or a build-server config that points at the wrong scheme. Our troubleshooting guide on Cursor Swift autocomplete covers the common failure modes in detail.
A few editor settings make Cursor feel closer to Xcode. In settings.json, enable format-on-save with swift-format if your team uses it, raise the SourceKit-LSP completion timeout for large projects, and turn on inlay hints for parameter names so call sites stay readable. Disable the bundled TypeScript and JavaScript suggestions inside Swift files so the Tab model is not competing with irrelevant web completions. Add a .cursorignore file that excludes Pods, .build, DerivedData, and generated sources; this keeps indexing fast and stops the AI from quoting stale or vendored code. If you work across several machines, commit your build-server generation script and your .cursorrules so every clone of the repository is one command away from full Swift intelligence. Finally, record the required toolchain version in your README, because a mismatched toolchain is the most common reason a teammate's autocomplete silently stops resolving your app's own modules.
No. You need to install the Swift extension, which uses SourceKit-LSP from the Swift toolchain, and for full iOS projects generate a buildServer.json with xcode-build-server. After that, Cursor offers Xcode-like completion, diagnostics, and go-to-definition for Swift.
SourceKit-LSP is the official Swift language server that ships with the Swift toolchain. It provides code completion, diagnostics, hover documentation, and navigation to editors that speak the Language Server Protocol, including VS Code and Cursor.
Usually no. Pure Swift Package Manager projects work with the toolchain and Swift extension alone. The xcode-build-server step is mainly needed for iOS app projects based on an .xcodeproj or .xcworkspace, so the language server can resolve build settings and frameworks.
Add a .cursorrules file or .cursor/rules directory at your project root describing your conventions — target iOS version, SwiftUI vs UIKit, concurrency style, and architecture. Cursor includes these rules in its AI context so generated Swift matches your codebase.