swiftwasm · kateinoigakukun · Jun 10, 2026 · Jun 10, 2026 · Jun 10, 2026 · Jun 10, 2026
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
@@ -12,18 +12,13 @@ jobs:
    strategy:
      matrix:
        entry:
-          - os: ubuntu-22.04
-            toolchain:
-              download-url: https://download.swift.org/swift-6.1-release/ubuntu2204/swift-6.1-RELEASE/swift-6.1-RELEASE-ubuntu22.04.tar.gz
-            wasi-backend: Node
-            target: "wasm32-unknown-wasi"
-            env: |
-              JAVASCRIPTKIT_DISABLE_TRACING_TRAIT=1
          - os: ubuntu-24.04
            toolchain:
              download-url: https://download.swift.org/development/ubuntu2404/swift-DEVELOPMENT-SNAPSHOT-2025-12-01-a/swift-DEVELOPMENT-SNAPSHOT-2025-12-01-a-ubuntu24.04.tar.gz
            wasi-backend: Node
            target: "wasm32-unknown-wasip1"
+            env: |
+              JAVASCRIPTKIT_DISABLE_TRACING_TRAIT=1
          - os: ubuntu-24.04
            toolchain:
              download-url: https://download.swift.org/swift-6.3-branch/ubuntu2404/swift-6.3-DEVELOPMENT-SNAPSHOT-2026-03-05-a/swift-6.3-DEVELOPMENT-SNAPSHOT-2026-03-05-a-ubuntu24.04.tar.gz
@@ -77,10 +72,6 @@ jobs:
    strategy:
      matrix:
        entry:
-          - image: "swift:6.1.2"
-            swift-syntax-version: "601.0.0"
-          - image: "swift:6.2"
-            swift-syntax-version: "602.0.0"
          - image: "swift:6.3"
            swift-syntax-version: "603.0.0"
    runs-on: ubuntu-latest
@@ -110,7 +101,7 @@ jobs:
      matrix:
        include:
          - os: macos-15
-            xcode: Xcode_16.4
+            xcode: Xcode_26.0.1
    runs-on: ${{ matrix.os }}
    steps:
      - uses: actions/checkout@v6
@@ -134,7 +125,7 @@ jobs:
  format:
    runs-on: ubuntu-latest
    container:
-      image: swift:6.1.2
+      image: swift:6.3
    steps:
      - uses: actions/checkout@v6
      - run: ./Utilities/format.swift

diff --git a/Examples/Embedded/README.md b/Examples/Embedded/README.md
@@ -1,6 +1,6 @@
 # Embedded example

-Requires a recent DEVELOPMENT-SNAPSHOT toolchain. (tested with swift-6.1-DEVELOPMENT-SNAPSHOT-2025-02-21-a)
+Requires a recent DEVELOPMENT-SNAPSHOT toolchain.

 ```sh
 $ ./build.sh

diff --git a/Package@swift-6.1.swift b/Package@swift-6.1.swift
diff --git a/Plugins/PackageToJS/Tests/ExampleTests.swift b/Plugins/PackageToJS/Tests/ExampleTests.swift
@@ -297,7 +297,6 @@ extension Trait where Self == ConditionTrait {
        }
    }

-    #if compiler(>=6.1)
    @Test(.requireSwiftSDK)
    func testingWithCoverage() throws {
        let swiftSDKID = try #require(Self.getSwiftSDKID())
@@ -325,7 +324,6 @@ extension Trait where Self == ConditionTrait {
            }
        }
    }
-    #endif
    #endif  // compiler(>=6.3)

    @Test(.requireSwiftSDK(triple: "wasm32-unknown-wasip1-threads"))
@@ -379,7 +377,6 @@ extension Trait where Self == ConditionTrait {
        }
    }

-    #if compiler(>=6.1)
    // TODO: Remove triple restriction once swift-testing is shipped in p1-threads SDK
    @Test(.requireSwiftSDK(triple: "wasm32-unknown-wasi"))
    func continuationLeakInTest_SwiftTesting() throws {
@@ -391,8 +388,6 @@ extension Trait where Self == ConditionTrait {
            try runSwift(["package", "--disable-sandbox", "--swift-sdk", swiftSDKID, "js", "test"], [:])
        }
    }
-    #endif
-
    @Test(.requireSwiftSDK)
    func playwrightOnPageLoad_XCTest() throws {
        let swiftSDKID = try #require(Self.getSwiftSDKID())
@@ -413,7 +408,6 @@ extension Trait where Self == ConditionTrait {
        }
    }

-    #if compiler(>=6.1)
    // TODO: Remove triple restriction once swift-testing is shipped in p1-threads SDK
    @Test(.requireSwiftSDK(triple: "wasm32-unknown-wasi"))
    func playwrightOnPageLoad_SwiftTesting() throws {
@@ -434,5 +428,4 @@ extension Trait where Self == ConditionTrait {
            )
        }
    }
-    #endif
 }
diff --git a/README.md b/README.md
@@ -120,6 +120,10 @@ Use the [BridgeJS Playground](https://swiftwasm.org/JavaScriptKit/PlayBridgeJS/)

 Check out the [examples](https://github.com/swiftwasm/JavaScriptKit/tree/main/Examples) for more detailed usage patterns.

+## Minimum Supported Swift Version (MSSV)
+
+The minimum supported Swift version is 6.3.
+
 ## Contributing

 Contributions are welcome! See [CONTRIBUTING.md](CONTRIBUTING.md) for details on how to contribute to the project.

diff --git a/Sources/JavaScriptEventLoop/JSRemote.swift b/Sources/JavaScriptEventLoop/JSRemote.swift
@@ -62,7 +62,7 @@ extension JSRemote where T == JSObject {
    ///
    /// - Parameter object: The JavaScript object to reference remotely.
    public init(_ object: JSObject) {
-        #if compiler(>=6.1) && _runtime(_multithreaded)
+        #if _runtime(_multithreaded)
        self.init(sourceObject: object, sourceTid: object.ownerTid)
        #else
        self.init(sourceObject: object, sourceTid: -1)
@@ -92,7 +92,7 @@ extension JSRemote where T == JSObject {
    public func withJSObject<R: Sendable, E: Error>(
        _ body: @Sendable @escaping (JSObject) throws(E) -> R
    ) async throws(E) -> sending R {
-        #if compiler(>=6.1) && _runtime(_multithreaded)
+        #if _runtime(_multithreaded)
        if storage.sourceTid == swjs_get_worker_thread_id_cached() {
            return try body(storage.sourceObject)
        }
@@ -137,13 +137,11 @@ private final class _JSRemoteContext: @unchecked Sendable {
    }
 }

-#if compiler(>=6.1)
 @_expose(wasm, "swjs_invoke_remote_jsobject_body")
 @_cdecl("swjs_invoke_remote_jsobject_body")
-#endif
 @available(macOS 10.15, iOS 13.0, watchOS 6.0, tvOS 13.0, *)
 func _swjs_invoke_remote_jsobject_body(_ contextPtr: UnsafeRawPointer?) -> Bool {
-    #if compiler(>=6.1) && _runtime(_multithreaded)
+    #if _runtime(_multithreaded)
    guard let contextPtr else { return true }
    let context = Unmanaged<_JSRemoteContext>.fromOpaque(contextPtr).takeRetainedValue()