diff --git a/.github/workflows/compatibility_tests.yml b/.github/workflows/compatibility_tests.yml
index 9dbaeed2..efeaf09a 100644
--- a/.github/workflows/compatibility_tests.yml
+++ b/.github/workflows/compatibility_tests.yml
@@ -17,8 +17,10 @@ jobs:
       matrix:
         include:
           - os: macos-15
-            xcode-version: "26.3"   # Swift 6.2.4
-    runs-on: ${{ matrix.os }}
+            xcode-version: "26.6"   # Swift 6.3.3
+    runs-on:
+      - ${{ matrix.os }}
+      - xcode-26.6
     env:
       OPENATTRIBUTEGRAPH_WERROR: 1
       OPENATTRIBUTEGRAPH_COMPATIBILITY_TEST: 1
@@ -49,9 +51,7 @@ jobs:
         shell: bash
       - name: Run tests against Apple's AttributeGraph on macOS via SwiftPM
         run: |
-          # Swift 6.2.4 crashes while indexing C++ interop test targets.
           swift test \
-            --disable-index-store \
             --build-path .build-compatibility-test-debug
       - name: Run tests against Apple's AttributeGraph on macOS via Xcode
         run: |
diff --git a/.github/workflows/compute.yml b/.github/workflows/compute.yml
index ec4c258d..9024a523 100644
--- a/.github/workflows/compute.yml
+++ b/.github/workflows/compute.yml
@@ -12,9 +12,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        # Swift 6.2.4 crashes swift-frontend when compiling C++ interop on Linux.
-        # Swift 6.3.2 has been verified locally on Linux.
-        swift_version: ["6.3.2"]
+        swift_version: ["6.3.3"]
     runs-on: ubuntu-22.04
     env:
       OPENATTRIBUTEGRAPH_WERROR: 1
@@ -37,8 +35,10 @@ jobs:
       fail-fast: false
       matrix:
         os: [macos-15]
-        xcode-version: ["26.3"]
-    runs-on: ${{ matrix.os }}
+        xcode-version: ["26.6"]
+    runs-on:
+      - ${{ matrix.os }}
+      - xcode-26.6
     env:
       OPENATTRIBUTEGRAPH_WERROR: 1
       OPENATTRIBUTEGRAPH_OPENATTRIBUTESHIMS_COMPUTE: 1
@@ -63,12 +63,14 @@ jobs:
       fail-fast: false
       matrix:
         os: [macos-15]
-        xcode-version: ["26.3"]
+        xcode-version: ["26.6"]
         ios-version: ["18.5"]
         include:
           - ios-version: "18.5"
             ios-simulator-name: "iPhone 16 Pro"
-    runs-on: ${{ matrix.os }}
+    runs-on:
+      - ${{ matrix.os }}
+      - xcode-26.6
     env:
       OPENATTRIBUTEGRAPH_WERROR: 1
       OPENATTRIBUTEGRAPH_OPENATTRIBUTESHIMS_COMPUTE: 1
diff --git a/.github/workflows/ios.yml b/.github/workflows/ios.yml
index 317e91c9..ae168895 100644
--- a/.github/workflows/ios.yml
+++ b/.github/workflows/ios.yml
@@ -16,12 +16,14 @@ jobs:
       fail-fast: false
       matrix:
         os: [macos-15]
-        xcode-version: ["26.3"]   # Swift 6.2.4
+        xcode-version: ["26.6"]   # Swift 6.3.3
         ios-version: ["18.5"]
         include:
           - ios-version: "18.5"
             ios-simulator-name: "iPhone 16 Pro"
-    runs-on: ${{ matrix.os }}
+    runs-on:
+      - ${{ matrix.os }}
+      - xcode-26.6
     env:
       OPENATTRIBUTEGRAPH_WERROR: 1
       OPENATTRIBUTEGRAPH_USE_LOCAL_DEPS: 1
@@ -52,7 +54,6 @@ jobs:
       - name: Build in debug mode on iOS
         run: |
           source Scripts/Tuist/common.sh
-          # Swift 6.2.4 crashes while indexing C++ interop test targets.
           tuist_xcodebuild \
             "${RUNNER_TEMP:-/tmp}/openattributegraph-ios-build-${GITHUB_RUN_ID}-${GITHUB_RUN_ATTEMPT:-0}.xcresult" \
             build \
@@ -63,12 +64,10 @@ jobs:
             -derivedDataPath .build-debug \
             -skipMacroValidation \
             -skipPackagePluginValidation \
-            COMPILER_INDEX_STORE_ENABLE=NO \
             OTHER_SWIFT_FLAGS="-warnings-as-errors"
       - name: Build and run tests in debug mode with coverage on iOS Simulator
         run: |
           source Scripts/Tuist/common.sh
-          # Swift 6.2.4 crashes while indexing C++ interop test targets.
           tuist_xcodebuild \
             "${RUNNER_TEMP:-/tmp}/openattributegraph-ios-test-${GITHUB_RUN_ID}-${GITHUB_RUN_ATTEMPT:-0}.xcresult" \
             test \
@@ -79,8 +78,7 @@ jobs:
             -enableCodeCoverage=YES \
             -derivedDataPath .build-test-debug \
             -skipPackagePluginValidation \
-            -skipMacroValidation \
-            COMPILER_INDEX_STORE_ENABLE=NO
+            -skipMacroValidation
             # OTHER_SWIFT_FLAGS="-warnings-as-errors" Conflicting options '-warnings-as-errors' and '-suppress-warnings'
       - name: Generate iOS coverage report
         run: |
diff --git a/.github/workflows/macos.yml b/.github/workflows/macos.yml
index 8d2946a7..f13fd2b8 100644
--- a/.github/workflows/macos.yml
+++ b/.github/workflows/macos.yml
@@ -13,8 +13,10 @@ jobs:
       fail-fast: false
       matrix:
         os: [macos-15]
-        xcode-version: ["26.3"]   # Swift 6.2.4
-    runs-on: ${{ matrix.os }}
+        xcode-version: ["26.6"]   # Swift 6.3.3
+    runs-on:
+      - ${{ matrix.os }}
+      - xcode-26.6
     env:
       OPENATTRIBUTEGRAPH_WERROR: 1
       OPENATTRIBUTEGRAPH_USE_LOCAL_DEPS: 1
@@ -34,9 +36,7 @@ jobs:
         shell: bash
       - name: Build and run tests in debug mode with coverage
         run: |
-          # Swift 6.2.4 crashes while indexing C++ interop test targets.
           swift test \
-            --disable-index-store \
             -c debug \
             --enable-code-coverage \
             --build-path .build-test-debug
@@ -46,9 +46,7 @@ jobs:
             > coverage.txt
       - name: Build and run tests in release mode
         run: |
-          # Swift 6.2.4 crashes while indexing C++ interop test targets.
           swift test \
-            --disable-index-store \
             -c release \
             --enable-code-coverage \
             --build-path .build-test-release
diff --git a/.github/workflows/oag_binary.yml b/.github/workflows/oag_binary.yml
index 859d5431..211d69b1 100644
--- a/.github/workflows/oag_binary.yml
+++ b/.github/workflows/oag_binary.yml
@@ -13,8 +13,10 @@ jobs:
       fail-fast: false
       matrix:
         os: [macos-15]
-        xcode-version: ["26.3"]
-    runs-on: ${{ matrix.os }}
+        xcode-version: ["26.6"]
+    runs-on:
+      - ${{ matrix.os }}
+      - xcode-26.6
     env:
       OPENATTRIBUTEGRAPH_WERROR: 1
       OPENATTRIBUTEGRAPH_OPENATTRIBUTESHIMS_OAG_USE_BINARY: 1
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index ba757530..9d569f0a 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -8,7 +8,9 @@ on:
 jobs:
   release:
     name: Build and Publish Release
-    runs-on: macos-15
+    runs-on:
+      - macos-15
+      - xcode-26.6
     permissions:
       contents: write
       id-token: write
@@ -22,7 +24,7 @@ jobs:
       - name: Setup Xcode
         uses: OpenSwiftUIProject/setup-xcode@v2
         with:
-          xcode-version: "26.3"
+          xcode-version: "26.6"
       - name: Set up mise
         uses: jdx/mise-action@v2
         with:
diff --git a/.github/workflows/ubuntu.yml b/.github/workflows/ubuntu.yml
index 45687ac2..a73ca5fb 100644
--- a/.github/workflows/ubuntu.yml
+++ b/.github/workflows/ubuntu.yml
@@ -12,9 +12,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        # Swift 6.2.4 crashes swift-frontend when compiling C++ interop tests on Linux.
-        # Swift 6.3.2 has been verified locally on Linux.
-        swift_version: ["6.3.2"]
+        swift_version: ["6.3.3"]
     runs-on: ubuntu-22.04
     env:
       OPENATTRIBUTEGRAPH_WERROR: 1
diff --git a/.github/workflows/xcframework.yml b/.github/workflows/xcframework.yml
index d7d5d7b4..56ef57dc 100644
--- a/.github/workflows/xcframework.yml
+++ b/.github/workflows/xcframework.yml
@@ -16,8 +16,10 @@ jobs:
       fail-fast: false
       matrix:
         os: [macos-15]
-        xcode-version: ["26.3"]   # Swift 6.2.4
-    runs-on: ${{ matrix.os }}
+        xcode-version: ["26.6"]   # Swift 6.3.3
+    runs-on:
+      - ${{ matrix.os }}
+      - xcode-26.6
     env:
       GH_TOKEN: ${{ github.token }}
     steps:
diff --git a/Example/Project.swift b/Example/Project.swift
index 5c3aec6e..ce75b319 100644
--- a/Example/Project.swift
+++ b/Example/Project.swift
@@ -1,13 +1,7 @@
 import ProjectDescription
 
-let indexStoreDisabledSettings: SettingsDictionary = [
-    // Swift 6.2.4 crashes while indexing C++ interop package targets.
-    "COMPILER_INDEX_STORE_ENABLE": "NO",
-]
-
 let project = Project(
     name: "Example",
-    settings: .settings(base: indexStoreDisabledSettings),
     targets: [
         .target(
             name: "Example",
@@ -19,8 +13,7 @@ let project = Project(
             dependencies: [
                 .sdk(name: "c++", type: .library),
                 .external(name: "OpenAttributeGraph"),
-            ],
-            settings: .settings(base: indexStoreDisabledSettings)
+            ]
         ),
     ]
 )
diff --git a/Example/Tuist.swift b/Example/Tuist.swift
index 81246c7a..82f67208 100644
--- a/Example/Tuist.swift
+++ b/Example/Tuist.swift
@@ -7,7 +7,12 @@ let tuist = Tuist(
     ),
     project: .tuist(
         generationOptions: .options(
-            enableCaching: Environment.isCI
+            optionalAuthentication: true,
+            enableCaching: Environment.isCI,
+            manifestEnvironment: [
+                "OPENSWIFTUI_*",
+                "OPENATTRIBUTEGRAPH_*",
+            ]
         )
     )
 )
diff --git a/Example/Tuist/Package.resolved b/Example/Tuist/Package.resolved
index e8cf1f64..45416df9 100644
--- a/Example/Tuist/Package.resolved
+++ b/Example/Tuist/Package.resolved
@@ -1,5 +1,5 @@
 {
-  "originHash" : "b4d69cd3c6294a612f2691e0c9ace37d5e8c8904296914f23e337abb762050c2",
+  "originHash" : "0e11c80665facc8857be461b32388524b07fef00c5f983d5bf4ac0cf97629dc3",
   "pins" : [
     {
       "identity" : "swift-numerics",
diff --git a/Example/Tuist/Package.swift b/Example/Tuist/Package.swift
index 9384c666..694e5912 100644
--- a/Example/Tuist/Package.swift
+++ b/Example/Tuist/Package.swift
@@ -1,18 +1,11 @@
-// swift-tools-version: 6.2
+// swift-tools-version: 6.3
 
 import PackageDescription
 
 #if TUIST
 import ProjectDescription
 
-let indexStoreDisabledSettings: SettingsDictionary = [
-    // Swift 6.2.4 crashes while indexing C++ interop package targets.
-    "COMPILER_INDEX_STORE_ENABLE": "NO",
-]
-
-let packageSettings = PackageSettings(
-    baseSettings: .settings(base: indexStoreDisabledSettings)
-)
+let packageSettings = PackageSettings()
 #endif
 
 let package = Package(
diff --git a/Example/mise.toml b/Example/mise.toml
index 8732ad26..fca2305c 100644
--- a/Example/mise.toml
+++ b/Example/mise.toml
@@ -1,2 +1,2 @@
 [tools]
-tuist = "4.203.1"
+tuist = "4.203.4"
diff --git a/Package.resolved b/Package.resolved
index b375f05a..1c35aafe 100644
--- a/Package.resolved
+++ b/Package.resolved
@@ -1,5 +1,5 @@
 {
-  "originHash" : "f9dba67a06993e034a027e1f7dac2f20c40df84b4ee6df328d5adb14de0fc0c8",
+  "originHash" : "c4ccda72589ac888395134589ceb70d0a1ffd78aa23c39f48ac96604e6230ce1",
   "pins" : [
     {
       "identity" : "swift-numerics",
diff --git a/Package.swift b/Package.swift
index 941d6063..fde853f9 100644
--- a/Package.swift
+++ b/Package.swift
@@ -1,4 +1,4 @@
-// swift-tools-version: 6.2
+// swift-tools-version: 6.3
 
 import Foundation
 import PackageDescription
diff --git a/README.md b/README.md
index 4d640246..11e28401 100644
--- a/README.md
+++ b/README.md
@@ -60,7 +60,7 @@ For a simpler setup, you can use the prebuilt XCFramework available on the [rele
 
 ## Build
 
-The current suggested toolchain to build the project is Swift 6.2.4 / Xcode 26.3.
+The current suggested toolchain to build the project is Swift 6.3.3 / Xcode 26.6.
 
 ### Clone Swift headers
 
diff --git a/Scripts/CI/ag_setup.sh b/Scripts/CI/ag_setup.sh
index f2859649..76cbe005 100755
--- a/Scripts/CI/ag_setup.sh
+++ b/Scripts/CI/ag_setup.sh
@@ -6,7 +6,7 @@ filepath() {
 }
 
 REPO_ROOT="$(dirname $(dirname $(dirname $(filepath $0))))"
-DARWINPRIVATEFRAMEWORKS_FALLBACK_REVISION="b0c3d94ff6b7200754ad2adf948fd3c6ebaef956"
+DARWINPRIVATEFRAMEWORKS_FALLBACK_REVISION="b7e6ba165f3763dd477f55cc55b4a63f51385571"
 
 clone_checkout_ag() {
   cd $REPO_ROOT
diff --git a/Tuist.swift b/Tuist.swift
index fb0efdc2..82f67208 100644
--- a/Tuist.swift
+++ b/Tuist.swift
@@ -7,6 +7,7 @@ let tuist = Tuist(
     ),
     project: .tuist(
         generationOptions: .options(
+            optionalAuthentication: true,
             enableCaching: Environment.isCI,
             manifestEnvironment: [
                 "OPENSWIFTUI_*",
diff --git a/Tuist/Package.swift b/Tuist/Package.swift
index fccb7e3b..582b73f4 100644
--- a/Tuist/Package.swift
+++ b/Tuist/Package.swift
@@ -1,4 +1,4 @@
-// swift-tools-version: 6.2
+// swift-tools-version: 6.3
 import PackageDescription
 
 #if TUIST
diff --git a/mise.toml b/mise.toml
index 8732ad26..fca2305c 100644
--- a/mise.toml
+++ b/mise.toml
@@ -1,2 +1,2 @@
 [tools]
-tuist = "4.203.1"
+tuist = "4.203.4"