diff --git a/.github/actions/build-npm-package/action.yml b/.github/actions/build-npm-package/action.yml
index 2c5dd61a7d67..e3771ce3d51a 100644
--- a/.github/actions/build-npm-package/action.yml
+++ b/.github/actions/build-npm-package/action.yml
@@ -31,6 +31,15 @@ runs:
         pattern: ReactCore*
         path: ./packages/react-native/ReactAndroid/external-artifacts/artifacts
         merge-multiple: true
+    # ReactNativeDependenciesHeaders* is already covered by the
+    # ReactNativeDependencies* pattern above; ReactNativeHeaders* needs its own.
+    - name: Download ReactNativeHeaders artifacts
+      if: ${{ inputs.skip-apple-prebuilts != 'true' }}
+      uses: actions/download-artifact@v7
+      with:
+        pattern: ReactNativeHeaders*
+        path: ./packages/react-native/ReactAndroid/external-artifacts/artifacts
+        merge-multiple: true
     - name: Print Artifacts Directory
       if: ${{ inputs.skip-apple-prebuilts != 'true' }}
       shell: bash
diff --git a/.github/actions/test-ios-rntester/action.yml b/.github/actions/test-ios-rntester/action.yml
index fbb2d7474c38..129c93b36d3b 100644
--- a/.github/actions/test-ios-rntester/action.yml
+++ b/.github/actions/test-ios-rntester/action.yml
@@ -15,9 +15,18 @@ inputs:
     required: false
     default: false
   use-frameworks:
-    description: Whether we have to build with Dynamic Frameworks. If this is set to true, it builds from source
+    description: Whether we have to build with Dynamic Frameworks.
     required: false
     default: false
+  use-prebuilds:
+    description: >-
+      Whether to consume the prebuilt ReactCore/ReactNativeDependencies
+      artifacts. 'auto' (default) keeps the historical coupling: prebuilds for
+      static, source for dynamic frameworks. Pass 'true' with
+      use-frameworks:true for the prebuilt + dynamic-frameworks lane (the
+      config of the 2026-07-03 SocketRocket dual-copy regression).
+    required: false
+    default: auto
 
 runs:
   using: composite
@@ -41,24 +50,38 @@ runs:
     - name: Prepare IOS Tests
       if: ${{ inputs.run-unit-tests == 'true' }}
       uses: ./.github/actions/prepare-ios-tests
+    - name: Resolve prebuilds mode
+      id: prebuilds
+      shell: bash
+      run: |
+        if [[ "${{ inputs.use-prebuilds }}" == "auto" ]]; then
+          # Historical coupling: prebuilds for static, source for dynamic frameworks.
+          if [[ "${{ inputs.use-frameworks }}" == "true" ]]; then
+            echo "enabled=false" >> "$GITHUB_OUTPUT"
+          else
+            echo "enabled=true" >> "$GITHUB_OUTPUT"
+          fi
+        else
+          echo "enabled=${{ inputs.use-prebuilds }}" >> "$GITHUB_OUTPUT"
+        fi
     - name: Download ReactNativeDependencies
-      if: ${{ inputs.use-frameworks == 'false' }}
+      if: ${{ steps.prebuilds.outputs.enabled == 'true' }}
       uses: actions/download-artifact@v7
       with:
         name: ReactNativeDependencies${{ inputs.flavor }}.xcframework.tar.gz
         path: /tmp/third-party/
     - name: Print third-party folder
-      if: ${{ inputs.use-frameworks == 'false' }}
+      if: ${{ steps.prebuilds.outputs.enabled == 'true' }}
       shell: bash
       run: ls -lR /tmp/third-party
     - name: Download React Native Prebuilds
-      if: ${{ inputs.use-frameworks == 'false' }}
+      if: ${{ steps.prebuilds.outputs.enabled == 'true' }}
       uses: actions/download-artifact@v7
       with:
         name: ReactCore${{ inputs.flavor }}.xcframework.tar.gz
         path: /tmp/ReactCore
     - name: Print ReactCore folder
-      if: ${{ inputs.use-frameworks == 'false' }}
+      if: ${{ steps.prebuilds.outputs.enabled == 'true' }}
       shell: bash
       run: ls -lR /tmp/ReactCore
     - name: Install CocoaPods dependencies
@@ -66,8 +89,8 @@ runs:
       run: |
         if [[ ${{ inputs.use-frameworks }} == "true" ]]; then
           export USE_FRAMEWORKS=dynamic
-        else
-          # If use-frameworks is false, let's use prebuilds
+        fi
+        if [[ "${{ steps.prebuilds.outputs.enabled }}" == "true" ]]; then
           export RCT_USE_LOCAL_RN_DEP="/tmp/third-party/ReactNativeDependencies${{ inputs.flavor }}.xcframework.tar.gz"
           export RCT_TESTONLY_RNCORE_TARBALL_PATH="/tmp/ReactCore/ReactCore${{ inputs.flavor }}.xcframework.tar.gz"
         fi
diff --git a/.github/workflow-scripts/__tests__/verifyArtifactsAreOnMaven-test.js b/.github/workflow-scripts/__tests__/verifyArtifactsAreOnMaven-test.js
index e77e7c4e2e49..8e9758f28609 100644
--- a/.github/workflow-scripts/__tests__/verifyArtifactsAreOnMaven-test.js
+++ b/.github/workflow-scripts/__tests__/verifyArtifactsAreOnMaven-test.js
@@ -22,6 +22,28 @@ jest.mock('../utils.js', () => ({
 process.exit = mockExit;
 global.fetch = mockFetch;
 
+const BASE_URL =
+  'https://repo1.maven.org/maven2/com/facebook/react/react-native-artifacts';
+
+// The verifier HEAD-checks the POM plus every classifier tarball attached to
+// the react-native-artifacts publication (external-artifacts/build.gradle.kts).
+const expectedUrls = version => [
+  `${BASE_URL}/${version}/react-native-artifacts-${version}.pom`,
+  ...[
+    'reactnative-core-debug',
+    'reactnative-core-release',
+    'reactnative-dependencies-debug',
+    'reactnative-dependencies-release',
+    'reactnative-headers-debug',
+    'reactnative-headers-release',
+    'reactnative-dependencies-headers-debug',
+    'reactnative-dependencies-headers-release',
+  ].map(
+    classifier =>
+      `${BASE_URL}/${version}/react-native-artifacts-${version}-${classifier}.tar.gz`,
+  ),
+];
+
 describe('#verifyArtifactsAreOnMaven', () => {
   beforeEach(jest.clearAllMocks);
 
@@ -29,17 +51,18 @@ describe('#verifyArtifactsAreOnMaven', () => {
     mockSleep.mockReturnValueOnce(Promise.resolve()).mockImplementation(() => {
       throw new Error('Should not be called again!');
     });
+    // First attempt: the POM is not there yet. Second attempt: every URL is.
     mockFetch
       .mockReturnValueOnce(Promise.resolve({status: 404}))
-      .mockReturnValueOnce(Promise.resolve({status: 200}));
+      .mockReturnValue(Promise.resolve({status: 200}));
 
     const version = '0.78.1';
     await verifyArtifactsAreOnMaven(version);
 
     expect(mockSleep).toHaveBeenCalledTimes(1);
-    expect(mockFetch).toHaveBeenCalledWith(
-      'https://repo1.maven.org/maven2/com/facebook/react/react-native-artifacts/0.78.1/react-native-artifacts-0.78.1.pom',
-    );
+    for (const url of expectedUrls('0.78.1')) {
+      expect(mockFetch).toHaveBeenCalledWith(url, {method: 'HEAD'});
+    }
   });
 
   it('waits for the packages to be published on maven, when version starts with v', async () => {
@@ -48,27 +71,46 @@ describe('#verifyArtifactsAreOnMaven', () => {
     });
     mockFetch
       .mockReturnValueOnce(Promise.resolve({status: 404}))
-      .mockReturnValueOnce(Promise.resolve({status: 200}));
+      .mockReturnValue(Promise.resolve({status: 200}));
 
     const version = 'v0.78.1';
     await verifyArtifactsAreOnMaven(version);
 
     expect(mockSleep).toHaveBeenCalledTimes(1);
-    expect(mockFetch).toHaveBeenCalledWith(
-      'https://repo1.maven.org/maven2/com/facebook/react/react-native-artifacts/0.78.1/react-native-artifacts-0.78.1.pom',
-    );
+    for (const url of expectedUrls('0.78.1')) {
+      expect(mockFetch).toHaveBeenCalledWith(url, {method: 'HEAD'});
+    }
   });
 
   it('passes immediately if packages are already on Maven', async () => {
-    mockFetch.mockReturnValueOnce(Promise.resolve({status: 200}));
+    mockFetch.mockReturnValue(Promise.resolve({status: 200}));
 
     const version = '0.78.1';
     await verifyArtifactsAreOnMaven(version);
 
     expect(mockSleep).toHaveBeenCalledTimes(0);
-    expect(mockFetch).toHaveBeenCalledWith(
-      'https://repo1.maven.org/maven2/com/facebook/react/react-native-artifacts/0.78.1/react-native-artifacts-0.78.1.pom',
-    );
+    // All nine URLs (POM + 8 classifier tarballs) are verified in one pass.
+    expect(mockFetch).toHaveBeenCalledTimes(9);
+    for (const url of expectedUrls('0.78.1')) {
+      expect(mockFetch).toHaveBeenCalledWith(url, {method: 'HEAD'});
+    }
+  });
+
+  it('waits when a classifier artifact is missing even though the POM exists', async () => {
+    mockSleep.mockReturnValueOnce(Promise.resolve()).mockImplementation(() => {
+      throw new Error('Should not be called again!');
+    });
+    // First attempt: POM ok, first classifier missing. Second attempt: all ok.
+    mockFetch
+      .mockReturnValueOnce(Promise.resolve({status: 200}))
+      .mockReturnValueOnce(Promise.resolve({status: 404}))
+      .mockReturnValue(Promise.resolve({status: 200}));
+
+    const version = '0.78.1';
+    await verifyArtifactsAreOnMaven(version);
+
+    expect(mockSleep).toHaveBeenCalledTimes(1);
+    expect(mockExit).not.toHaveBeenCalled();
   });
 
   it('tries 90 times and then exits', async () => {
@@ -82,6 +124,7 @@ describe('#verifyArtifactsAreOnMaven', () => {
     expect(mockExit).toHaveBeenCalledWith(1);
     expect(mockFetch).toHaveBeenCalledWith(
       'https://repo1.maven.org/maven2/com/facebook/react/react-native-artifacts/0.78.1/react-native-artifacts-0.78.1.pom',
+      {method: 'HEAD'},
     );
   });
 });
diff --git a/.github/workflow-scripts/verifyArtifactsAreOnMaven.js b/.github/workflow-scripts/verifyArtifactsAreOnMaven.js
index 1bb46163e0a2..3acc37023bed 100644
--- a/.github/workflow-scripts/verifyArtifactsAreOnMaven.js
+++ b/.github/workflow-scripts/verifyArtifactsAreOnMaven.js
@@ -7,6 +7,7 @@
  * @format
  */
 
+// @flow
 const {log, sleep} = require('./utils');
 
 const SLEEP_S = 60; // 1 minute
@@ -15,23 +16,49 @@ const ARTIFACT_URL =
   'https://repo1.maven.org/maven2/com/facebook/react/react-native-artifacts/';
 const ARTIFACT_NAME = 'react-native-artifacts-';
 
+// The classifier-suffixed tarballs attached to the react-native-artifacts
+// publication (external-artifacts/build.gradle.kts). The POM check alone
+// would pass even when a classifier artifact never made it to Maven.
+const ARTIFACT_CLASSIFIERS = [
+  'reactnative-core-debug',
+  'reactnative-core-release',
+  'reactnative-dependencies-debug',
+  'reactnative-dependencies-release',
+  'reactnative-headers-debug',
+  'reactnative-headers-release',
+  'reactnative-dependencies-headers-debug',
+  'reactnative-dependencies-headers-release',
+];
+
 async function verifyArtifactsAreOnMaven(version, retries = MAX_RETRIES) {
   if (version.startsWith('v')) {
     version = version.substring(1);
   }
 
-  const artifactUrl = `${ARTIFACT_URL}${version}/${ARTIFACT_NAME}${version}.pom`;
+  const urls = [
+    `${ARTIFACT_URL}${version}/${ARTIFACT_NAME}${version}.pom`,
+    ...ARTIFACT_CLASSIFIERS.map(
+      classifier =>
+        `${ARTIFACT_URL}${version}/${ARTIFACT_NAME}${version}-${classifier}.tar.gz`,
+    ),
+  ];
   for (let currentAttempt = 1; currentAttempt <= retries; currentAttempt++) {
-    const response = await fetch(artifactUrl);
-
-    if (response.status !== 200) {
-      log(
-        `${currentAttempt}) Artifact's for version ${version} are not on maven yet.\nURL: ${artifactUrl}\nLet's wait a minute and try again.\n`,
-      );
-      await sleep(SLEEP_S);
-    } else {
+    let missingUrl = null;
+    for (const url of urls) {
+      const response = await fetch(url, {method: 'HEAD'});
+      if (response.status !== 200) {
+        missingUrl = url;
+        break;
+      }
+    }
+
+    if (missingUrl == null) {
       return;
     }
+    log(
+      `${currentAttempt}) Artifact's for version ${version} are not on maven yet.\nURL: ${missingUrl}\nLet's wait a minute and try again.\n`,
+    );
+    await sleep(SLEEP_S);
   }
 
   log(
diff --git a/.github/workflows/prebuild-ios-core.yml b/.github/workflows/prebuild-ios-core.yml
index 6809e7ffceff..8c466aa17863 100644
--- a/.github/workflows/prebuild-ios-core.yml
+++ b/.github/workflows/prebuild-ios-core.yml
@@ -167,9 +167,11 @@ jobs:
         if: steps.restore-ios-xcframework.outputs.cache-hit != 'true'
         shell: bash
         run: |
-          # ReactNativeHeaders.xcframework (built by the compose step) folds in
-          # the third-party deps namespaces (folly/glog/boost/...), so the deps
-          # headers must be staged here too — not just in build-slices.
+          # ReactNativeHeaders.xcframework is pure-RN (the deps namespaces ship
+          # in the ReactNativeDependenciesHeaders sidecar built by the deps
+          # prebuild), but the headers-verify compile gates still need the deps
+          # headers on their include path (folly/glog/... reached from RN's
+          # public headers), so the deps artifact is staged here too.
           tar -xzf /tmp/third-party/ReactNativeDependencies${{ matrix.flavor }}.xcframework.tar.gz -C /tmp/third-party/
           mkdir -p packages/react-native/third-party/
           mv /tmp/third-party/packages/react-native/third-party/ReactNativeDependencies.xcframework packages/react-native/third-party/ReactNativeDependencies.xcframework
@@ -212,6 +214,15 @@ jobs:
         run: |
           cd packages/react-native/.build/output/xcframeworks/${{matrix.flavor}}/Symbols
           tar -cz -f ../../ReactCore${{ matrix.flavor }}.framework.dSYM.tar.gz .
+      - name: Rename ReactNativeHeaders XCFramework tarball
+        if: steps.restore-ios-xcframework.outputs.cache-hit != 'true'
+        run: |
+          # The compose step already tars ReactNativeHeaders.xcframework standalone;
+          # published as its own Maven artifact (classifier reactnative-headers-*)
+          # so SwiftPM consumers can wire it as a separate binaryTarget. It also
+          # ships inside the ReactCore tarball for the CocoaPods pod.
+          cp packages/react-native/.build/output/xcframeworks/${{matrix.flavor}}/ReactNativeHeaders.xcframework.tar.gz \
+            packages/react-native/.build/output/xcframeworks/ReactNativeHeaders${{matrix.flavor}}.xcframework.tar.gz
       - name: Upload XCFramework Artifact
         uses: actions/upload-artifact@v6
         with:
@@ -222,6 +233,11 @@ jobs:
         with:
           name: ReactCore${{ matrix.flavor }}.framework.dSYM.tar.gz
           path: packages/react-native/.build/output/xcframeworks/ReactCore${{matrix.flavor}}.framework.dSYM.tar.gz
+      - name: Upload ReactNativeHeaders XCFramework Artifact
+        uses: actions/upload-artifact@v6
+        with:
+          name: ReactNativeHeaders${{ matrix.flavor }}.xcframework.tar.gz
+          path: packages/react-native/.build/output/xcframeworks/ReactNativeHeaders${{matrix.flavor}}.xcframework.tar.gz
       - name: Save cache if present
         if: ${{ github.ref == 'refs/heads/main' }} # To avoid that the cache explode
         uses: actions/cache/save@v5
@@ -229,4 +245,5 @@ jobs:
           path: |
             packages/react-native/.build/output/xcframeworks/ReactCore${{matrix.flavor}}.xcframework.tar.gz
             packages/react-native/.build/output/xcframeworks/ReactCore${{matrix.flavor}}.framework.dSYM.tar.gz
+            packages/react-native/.build/output/xcframeworks/ReactNativeHeaders${{matrix.flavor}}.xcframework.tar.gz
           key: v2-ios-core-xcframework-${{ matrix.flavor }}-${{ hashFiles('packages/react-native/Package.swift', 'packages/react-native/scripts/ios-prebuild/*.js', 'packages/react-native/scripts/ios-prebuild.js', 'packages/react-native/React/**/*', 'packages/react-native/ReactCommon/**/*', 'packages/react-native/Libraries/**/*') }}
diff --git a/.github/workflows/prebuild-ios-dependencies.yml b/.github/workflows/prebuild-ios-dependencies.yml
index ab9322da3dd8..b4d4407ace87 100644
--- a/.github/workflows/prebuild-ios-dependencies.yml
+++ b/.github/workflows/prebuild-ios-dependencies.yml
@@ -130,7 +130,7 @@ jobs:
         with:
           path: |
             packages/react-native/third-party/
-          key: v3-ios-dependencies-xcframework-${{ matrix.flavor }}-${{ hashfiles('scripts/releases/ios-prebuild/configuration.js') }}
+          key: v4-ios-dependencies-xcframework-${{ matrix.flavor }}-${{ hashfiles('scripts/releases/ios-prebuild/configuration.js', 'scripts/releases/ios-prebuild/compose-framework.js') }}
       # If cache hit, we already have our binary. We don't need to do anything.
       - name: Yarn Install
         if: steps.restore-xcframework.outputs.cache-hit != 'true'
@@ -164,7 +164,13 @@ jobs:
         if: steps.restore-xcframework.outputs.cache-hit != 'true'
         run: |
           tar -cz -f packages/react-native/third-party/ReactNativeDependencies${{ matrix.flavor }}.xcframework.tar.gz \
-            packages/react-native/third-party/ReactNativeDependencies.xcframework
+            packages/react-native/third-party/ReactNativeDependencies.xcframework \
+            packages/react-native/third-party/ReactNativeDependenciesHeaders.xcframework
+      - name: Compress Headers Sidecar XCFramework
+        if: steps.restore-xcframework.outputs.cache-hit != 'true'
+        run: |
+          tar -cz -f packages/react-native/third-party/ReactNativeDependenciesHeaders${{ matrix.flavor }}.xcframework.tar.gz \
+            packages/react-native/third-party/ReactNativeDependenciesHeaders.xcframework
       - name: Show Symbol folder content
         if: steps.restore-xcframework.outputs.cache-hit != 'true'
         run: ls -lR packages/react-native/third-party/Symbols
@@ -179,6 +185,11 @@ jobs:
         with:
           name: ReactNativeDependencies${{ matrix.flavor }}.xcframework.tar.gz
           path: packages/react-native/third-party/ReactNativeDependencies${{ matrix.flavor }}.xcframework.tar.gz
+      - name: Upload Headers Sidecar XCFramework Artifact
+        uses: actions/upload-artifact@v6
+        with:
+          name: ReactNativeDependenciesHeaders${{ matrix.flavor }}.xcframework.tar.gz
+          path: packages/react-native/third-party/ReactNativeDependenciesHeaders${{ matrix.flavor }}.xcframework.tar.gz
       - name: Upload dSYM Artifact
         uses: actions/upload-artifact@v6
         with:
@@ -191,5 +202,6 @@ jobs:
         with:
           path: |
             packages/react-native/third-party/ReactNativeDependencies${{ matrix.flavor }}.xcframework.tar.gz
+            packages/react-native/third-party/ReactNativeDependenciesHeaders${{ matrix.flavor }}.xcframework.tar.gz
             packages/react-native/third-party/ReactNativeDependencies${{ matrix.flavor }}.framework.dSYM.tar.gz
-          key: v3-ios-dependencies-xcframework-${{ matrix.flavor }}-${{ hashfiles('scripts/releases/ios-prebuild/configuration.js') }}
+          key: v4-ios-dependencies-xcframework-${{ matrix.flavor }}-${{ hashfiles('scripts/releases/ios-prebuild/configuration.js', 'scripts/releases/ios-prebuild/compose-framework.js') }}
diff --git a/.github/workflows/test-all.yml b/.github/workflows/test-all.yml
index 422a90c712ae..4c353e965dc2 100644
--- a/.github/workflows/test-all.yml
+++ b/.github/workflows/test-all.yml
@@ -155,6 +155,12 @@ jobs:
         uses: ./.github/actions/test-ios-rntester
         with:
           use-frameworks: ${{ matrix.frameworks }}
+          # Consume the prebuilt artifacts in the dynamic-frameworks cells too:
+          # prebuilt + use_frameworks is the config of the 2026-07-03
+          # SocketRocket dual-copy regression, previously covered by no lane
+          # (source-built dynamic frameworks stay covered by
+          # test_ios_rntester_dynamic_frameworks).
+          use-prebuilds: true
           flavor: ${{ matrix.flavor }}
 
   test_e2e_ios_rntester:
diff --git a/packages/react-native/React-Core-prebuilt.podspec b/packages/react-native/React-Core-prebuilt.podspec
index 36d191278a08..bc838fafef3a 100644
--- a/packages/react-native/React-Core-prebuilt.podspec
+++ b/packages/react-native/React-Core-prebuilt.podspec
@@ -22,11 +22,15 @@ Pod::Spec.new do |s|
   #  - React.xcframework: the compiled core. Its per-slice React.framework carries
   #    every <React/...> header + the framework module map, so `#import <React/...>`
   #    and `@import React;` resolve through FRAMEWORK_SEARCH_PATHS automatically.
-  #  - ReactNativeHeaders.xcframework: headers-only. Carries every other namespace
-  #    (<react/...>, <yoga/...>, folly, glog, ...). Its headers are flattened into a
-  #    top-level Headers/ (see prepare_command) and exposed via the standard pod
-  #    header search path. (<hermes/...> is supplied by the hermes-engine pod here;
-  #    it is folded into ReactNativeHeaders only on the SwiftPM consumer side.)
+  #  - ReactNativeHeaders.xcframework: headers-only, PURE-RN. Carries every other
+  #    RN namespace (<react/...>, <yoga/...>, ...). Its headers are flattened into
+  #    a top-level Headers/ (see prepare_command) and exposed via the standard pod
+  #    header search path. The third-party deps namespaces (folly/glog/boost/...)
+  #    are NOT here — the ReactNativeDependencies pod serves them from its own
+  #    artifact (see scripts/cocoapods/__docs__/prebuilt-deps.md), wired through
+  #    add_rn_third_party_dependencies below. (<hermes/...> is supplied by the
+  #    hermes-engine pod here; it is folded into ReactNativeHeaders only on the
+  #    SwiftPM consumer side.)
   # There is no clang VFS overlay.
   s.vendored_frameworks    = "React.xcframework"
 
diff --git a/packages/react-native/ReactAndroid/external-artifacts/build.gradle.kts b/packages/react-native/ReactAndroid/external-artifacts/build.gradle.kts
index 1ed2851218df..e26ca9f61e62 100644
--- a/packages/react-native/ReactAndroid/external-artifacts/build.gradle.kts
+++ b/packages/react-native/ReactAndroid/external-artifacts/build.gradle.kts
@@ -53,6 +53,28 @@ val reactNativeDependenciesReleaseDSYMArtifact: PublishArtifact =
       classifier = "reactnative-dependencies-dSYM-release"
     }
 
+// [iOS] React Native Dependencies Headers — the headers-only LIBRARY-type
+// sidecar (per-slice Headers/ + HeadersPath) that SwiftPM auto-serves; the
+// binary xcframework above is framework-type and cannot expose headers to
+// SwiftPM binaryTargets. Also shipped INSIDE the deps tarball for CocoaPods.
+val reactNativeDependenciesHeadersDebugArtifactFile: RegularFile =
+    layout.projectDirectory.file("artifacts/ReactNativeDependenciesHeadersDebug.xcframework.tar.gz")
+val reactNativeDependenciesHeadersDebugArtifact: PublishArtifact =
+    artifacts.add("externalArtifacts", reactNativeDependenciesHeadersDebugArtifactFile) {
+      type = "tgz"
+      extension = "tar.gz"
+      classifier = "reactnative-dependencies-headers-debug"
+    }
+
+val reactNativeDependenciesHeadersReleaseArtifactFile: RegularFile =
+    layout.projectDirectory.file("artifacts/ReactNativeDependenciesHeadersRelease.xcframework.tar.gz")
+val reactNativeDependenciesHeadersReleaseArtifact: PublishArtifact =
+    artifacts.add("externalArtifacts", reactNativeDependenciesHeadersReleaseArtifactFile) {
+      type = "tgz"
+      extension = "tar.gz"
+      classifier = "reactnative-dependencies-headers-release"
+    }
+
 // [iOS] React Native Core
 val reactCoreDebugArtifactFile: RegularFile =
     layout.projectDirectory.file("artifacts/ReactCoreDebug.xcframework.tar.gz")
@@ -89,6 +111,27 @@ val reactCoreReleaseDSYMArtifact: PublishArtifact =
       classifier = "reactnative-core-dSYM-release"
     }
 
+// [iOS] React Native Headers — the pure-RN headers-only xcframework, published
+// standalone (it also ships inside the ReactCore tarball for CocoaPods) so
+// SwiftPM consumers can wire it as its own binaryTarget.
+val reactNativeHeadersDebugArtifactFile: RegularFile =
+    layout.projectDirectory.file("artifacts/ReactNativeHeadersDebug.xcframework.tar.gz")
+val reactNativeHeadersDebugArtifact: PublishArtifact =
+    artifacts.add("externalArtifacts", reactNativeHeadersDebugArtifactFile) {
+      type = "tgz"
+      extension = "tar.gz"
+      classifier = "reactnative-headers-debug"
+    }
+
+val reactNativeHeadersReleaseArtifactFile: RegularFile =
+    layout.projectDirectory.file("artifacts/ReactNativeHeadersRelease.xcframework.tar.gz")
+val reactNativeHeadersReleaseArtifact: PublishArtifact =
+    artifacts.add("externalArtifacts", reactNativeHeadersReleaseArtifactFile) {
+      type = "tgz"
+      extension = "tar.gz"
+      classifier = "reactnative-headers-release"
+    }
+
 apply(from = "../publish.gradle")
 
 publishing {
@@ -99,10 +142,14 @@ publishing {
       artifact(reactNativeDependenciesReleaseArtifact)
       artifact(reactNativeDependenciesDebugDSYMArtifact)
       artifact(reactNativeDependenciesReleaseDSYMArtifact)
+      artifact(reactNativeDependenciesHeadersDebugArtifact)
+      artifact(reactNativeDependenciesHeadersReleaseArtifact)
       artifact(reactCoreDebugArtifact)
       artifact(reactCoreReleaseArtifact)
       artifact(reactCoreDebugDSYMArtifact)
       artifact(reactCoreReleaseDSYMArtifact)
+      artifact(reactNativeHeadersDebugArtifact)
+      artifact(reactNativeHeadersReleaseArtifact)
     }
   }
 }
diff --git a/packages/react-native/scripts/cocoapods/__docs__/prebuilt-deps.md b/packages/react-native/scripts/cocoapods/__docs__/prebuilt-deps.md
index f52ed738480a..354d7592e625 100644
--- a/packages/react-native/scripts/cocoapods/__docs__/prebuilt-deps.md
+++ b/packages/react-native/scripts/cocoapods/__docs__/prebuilt-deps.md
@@ -13,17 +13,21 @@ xcframework binary, and the artifact's own
 `Headers/{folly,glog,boost,fmt,double-conversion,fast_float, SocketRocket}` are
 flattened into the pod's `Headers/` by the podspec's `prepare_command`.
 Consumers resolve bare `<folly/...>` / `<SocketRocket/...>` via CocoaPods
-public-header linkage from `s.dependency "ReactNativeDependencies"`, plus an
-explicit `HEADER_SEARCH_PATHS` entry
-(`$(PODS_ROOT)/ReactNativeDependencies/Headers`). The real source pods are
-neither depended on nor searched.
+public-header linkage from `s.dependency "ReactNativeDependencies"`, plus
+`HEADER_SEARCH_PATHS` entries pointing at
+`$(PODS_ROOT)/ReactNativeDependencies/Headers`: per-podspec via
+`add_rn_third_party_dependencies`, and globally (aggregate + every pod target)
+via `ReactNativeDependenciesUtils.configure_aggregate_xcconfig` at post-install
+— ReactNativeHeaders is pure-RN, so this is the only global home of the deps
+namespaces. The real source pods are neither depended on nor searched.
 
-NOTE: this is a CocoaPods-level contract. The deps XCFRAMEWORK itself is NOT
-self-serving: it is framework-type without `HeadersPath`, so its root `Headers/`
-is invisible to SPM binaryTargets (verified 2026-07-04 — `HeadersPath` is
-rejected on framework entries). In SPM the six C++ namespaces are served by
-ReactNativeHeaders.xcframework; serving them from the deps side requires the
-phase-2 headers-only library sidecar (see rn-deps-self-serving plan).
+For SPM, the deps XCFRAMEWORK itself cannot serve headers: it is framework-type
+without `HeadersPath`, and its root `Headers/` is invisible to SPM binaryTargets
+(verified 2026-07-04 — `HeadersPath` is rejected on framework entries). The deps
+prebuild therefore emits a headers-only LIBRARY-type sidecar,
+`ReactNativeDependenciesHeaders.xcframework` (same recipe as ReactNativeHeaders:
+stub archives + per-slice `Headers/`), which SPM auto-serves with zero flags.
+The sidecar ships inside the deps tarball and as a standalone artifact.
 
 ## Why SocketRocket is vended here
 
diff --git a/packages/react-native/scripts/cocoapods/rncore.rb b/packages/react-native/scripts/cocoapods/rncore.rb
index 1ff33b69c135..00b9327871e4 100644
--- a/packages/react-native/scripts/cocoapods/rncore.rb
+++ b/packages/react-native/scripts/cocoapods/rncore.rb
@@ -513,7 +513,9 @@ def self.get_nightly_npm_version()
     # only declares the React-Core-prebuilt dependency; it no longer touches xcconfigs.)
     #
     # `<React/...>` resolves through the vendored React.framework; this adds the search
-    # path to the flattened ReactNativeHeaders headers (every other namespace). There is
+    # path to the flattened ReactNativeHeaders headers (every other RN namespace —
+    # the third-party deps namespaces are served by the ReactNativeDependencies pod,
+    # see ReactNativeDependenciesUtils.configure_aggregate_xcconfig). There is
     # no clang VFS overlay.
     #
     # Parameters:
diff --git a/packages/react-native/scripts/cocoapods/rndependencies.rb b/packages/react-native/scripts/cocoapods/rndependencies.rb
index 20445517ed69..c78b4c1db8f2 100644
--- a/packages/react-native/scripts/cocoapods/rndependencies.rb
+++ b/packages/react-native/scripts/cocoapods/rndependencies.rb
@@ -150,6 +150,52 @@ def self.abort_if_use_local_rndeps_with_no_file()
       end
     end
 
+    # Single post-install injection site for the prebuilt deps header resolution.
+    # Adds the flattened ReactNativeDependencies/Headers search path to the
+    # aggregate (main app) target AND every pod target, mirroring
+    # ReactNativeCoreUtils.configure_aggregate_xcconfig. ReactNativeHeaders is
+    # pure-RN, so this path is the single global home of the third-party
+    # namespaces (folly/glog/boost/fmt/double-conversion/fast_float/
+    # SocketRocket): pods that never call add_rn_third_party_dependencies (nor
+    # depend on a facade) still compile RN headers that textually reach
+    # <folly/...>. No module-map activation needed — the deps headers are
+    # served textually; modules come from the ReactNativeDependencies pod.
+    def self.configure_aggregate_xcconfig(installer)
+        return if @@build_from_source
+
+        rndeps_log("Configuring xcconfig for prebuilt React Native Dependencies...")
+        headers_search_path = " \"$(PODS_ROOT)/ReactNativeDependencies/Headers\""
+
+        # Add the header search path to aggregate target xcconfigs (used by the main app target)
+        installer.aggregate_targets.each do |aggregate_target|
+            aggregate_target.xcconfigs.each do |config_name, config_file|
+                ReactNativePodsUtils.add_flag_to_map_with_inheritance(config_file.attributes, "HEADER_SEARCH_PATHS", headers_search_path)
+                xcconfig_path = aggregate_target.xcconfig_path(config_name)
+                config_file.save_as(xcconfig_path)
+            end
+        end
+
+        # Add the header search path to ALL pod targets (for pods that don't go
+        # through add_rn_third_party_dependencies)
+        installer.pod_targets.each do |pod_target|
+            pod_target.build_settings.each do |config_name, build_settings|
+                xcconfig_path = pod_target.xcconfig_path(config_name)
+                next unless File.exist?(xcconfig_path)
+
+                xcconfig = Xcodeproj::Config.new(xcconfig_path)
+
+                # Skip if the deps header search path is already present
+                header_search_paths = xcconfig.attributes["HEADER_SEARCH_PATHS"] || ""
+                next if header_search_paths.include?("ReactNativeDependencies/Headers")
+
+                ReactNativePodsUtils.add_flag_to_map_with_inheritance(xcconfig.attributes, "HEADER_SEARCH_PATHS", headers_search_path)
+                xcconfig.save_as(xcconfig_path)
+            end
+        end
+
+        rndeps_log("Prebuilt deps xcconfig configuration complete")
+    end
+
     def self.podspec_source_download_prebuild_release_tarball()
         # Warn if @@react_native_path is not set
         if @@react_native_path == ""
diff --git a/packages/react-native/scripts/ios-prebuild/__tests__/headers-spec-test.js b/packages/react-native/scripts/ios-prebuild/__tests__/headers-spec-test.js
index 167b3f47ea4f..2fc6f461f768 100644
--- a/packages/react-native/scripts/ios-prebuild/__tests__/headers-spec-test.js
+++ b/packages/react-native/scripts/ios-prebuild/__tests__/headers-spec-test.js
@@ -11,6 +11,7 @@
 'use strict';
 
 const {
+  DEPS_NAMESPACES,
   planFromInventory,
   renderNamespaceModuleMap,
   renderReactModuleMap,
@@ -218,6 +219,22 @@ describe('R11 redirect shims for dual-identity headers', () => {
   });
 });
 
+describe('DEPS_NAMESPACES (R2 — the deps sidecar namespace set)', () => {
+  test('includes SocketRocket: one physical home, in the sidecar', () => {
+    // Pre-sidecar, SocketRocket was excluded from relocation because a REAL
+    // pod vended it (the 2026-07-03 dual-copy regression). With the sidecar
+    // being the deps' single header home, it must be declared like every
+    // other deps namespace.
+    expect(DEPS_NAMESPACES).toContain('SocketRocket');
+  });
+
+  test('plan.depsNamespaces mirrors the spec list', () => {
+    expect(planFromInventory(validManifest()).depsNamespaces).toEqual(
+      DEPS_NAMESPACES,
+    );
+  });
+});
+
 describe('headers-verify gate pieces', () => {
   const {
     diffAgainstBaseline,
diff --git a/packages/react-native/scripts/ios-prebuild/__tests__/headers-xcframework-test.js b/packages/react-native/scripts/ios-prebuild/__tests__/headers-xcframework-test.js
new file mode 100644
index 000000000000..8cc6aa4f2f02
--- /dev/null
+++ b/packages/react-native/scripts/ios-prebuild/__tests__/headers-xcframework-test.js
@@ -0,0 +1,59 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @flow strict-local
+ * @format
+ */
+
+'use strict';
+
+const {buildDepsHeadersXcframework} = require('../headers-xcframework');
+const fs = require('fs');
+const os = require('os');
+const path = require('path');
+
+describe('buildDepsHeadersXcframework set-equality gate', () => {
+  let tmp /*: string */;
+  beforeEach(() => {
+    tmp = fs.mkdtempSync(path.join(os.tmpdir(), 'deps-headers-test-'));
+  });
+  afterEach(() => {
+    fs.rmSync(tmp, {recursive: true, force: true});
+  });
+
+  const mkHeaders = (namespaces /*: Array<string> */) => {
+    const dir = path.join(tmp, 'Headers');
+    fs.mkdirSync(dir, {recursive: true});
+    for (const ns of namespaces) {
+      fs.mkdirSync(path.join(dir, ns), {recursive: true});
+    }
+    return dir;
+  };
+
+  // Both gates throw BEFORE any staging or xcodebuild invocation, so these
+  // tests run without macOS tooling.
+  test('fails closed when a declared namespace is missing from the artifact', () => {
+    const headers = mkHeaders(['folly']);
+    expect(() =>
+      buildDepsHeadersXcframework(tmp, headers, ['folly', 'glog'], []),
+    ).toThrow(/missing from .*Headers: glog/);
+  });
+
+  test('fails closed when the artifact ships an undeclared namespace', () => {
+    const headers = mkHeaders(['folly', 'brand-new-dep']);
+    expect(() =>
+      buildDepsHeadersXcframework(tmp, headers, ['folly'], []),
+    ).toThrow(/undeclared in DEPS_NAMESPACES.*brand-new-dep/);
+  });
+
+  test('ignores loose files at the Headers root (directories are the namespace set)', () => {
+    const headers = mkHeaders(['folly']);
+    fs.writeFileSync(path.join(headers, 'stray.h'), '');
+    expect(() =>
+      buildDepsHeadersXcframework(tmp, headers, ['folly', 'glog'], []),
+    ).toThrow(/missing from .*Headers: glog/); // throws for glog, not stray.h
+  });
+});
diff --git a/packages/react-native/scripts/ios-prebuild/headers-compose.js b/packages/react-native/scripts/ios-prebuild/headers-compose.js
index 1e1eec92b19d..b4feaf118027 100644
--- a/packages/react-native/scripts/ios-prebuild/headers-compose.js
+++ b/packages/react-native/scripts/ios-prebuild/headers-compose.js
@@ -11,10 +11,13 @@
 /**
  * Headers compose — emits the headers-spec layout (rules R1–R8 in
  * headers-spec.js) into a React.xcframework and builds the headers-only
- * ReactNativeHeaders.xcframework beside it. The prebuild path (xcframework.js)
- * composes before signing (R7); `ensureHeadersLayout()` applies the same
- * emission to an already-cached artifact. One projector, spec-driven,
- * byte-identical output either way.
+ * ReactNativeHeaders.xcframework beside it (pure-RN: the third-party deps
+ * namespaces ship in the ReactNativeDependenciesHeaders sidecar instead —
+ * see headers-xcframework.js). The prebuild path (xcframework.js) composes
+ * before signing (R7); `ensureHeadersLayout()` applies the same emission to
+ * an already-cached artifact and builds the deps sidecar from the slot's
+ * deps headers. One projector, spec-driven, byte-identical output either
+ * way.
  */
 
 const {
@@ -25,12 +28,17 @@ const {
 const {computeInventory} = require('./headers-inventory');
 const {
   DEPS_NAMESPACES,
-  DEPS_NAMESPACES_NOT_RELOCATED,
   planFromInventory,
   renderNamespaceModuleMap,
   renderReactModuleMap,
   renderUmbrellaHeader,
 } = require('./headers-spec');
+const {
+  CATALYST_STUB_SLICE,
+  DEFAULT_STUB_SLICES,
+  buildDepsHeadersXcframework,
+  composeHeadersOnlyXcframework,
+} = require('./headers-xcframework');
 const {execSync} = require('child_process');
 const fs = require('fs');
 const path = require('path');
@@ -148,95 +156,29 @@ function emitReactFrameworkHeaders(
   );
 }
 
-/*::
-type StubSlice = {
-  name: string, // human label
-  sdk: string, // xcrun --sdk name
-  targets: Array<string>, // clang -target triples (lipo'd when > 1)
-};
-*/
-
-const DEFAULT_STUB_SLICES /*: Array<StubSlice> */ = [
-  {name: 'ios', sdk: 'iphoneos', targets: ['arm64-apple-ios15.0']},
-  {
-    name: 'ios-simulator',
-    sdk: 'iphonesimulator',
-    targets: [
-      'arm64-apple-ios15.0-simulator',
-      'x86_64-apple-ios15.0-simulator',
-    ],
-  },
-];
-
-// Mac Catalyst slice — used by the real compose (the cached-artifact
-// repackage path skips it to stay fast; React.xcframework carries it).
-const CATALYST_STUB_SLICE /*: StubSlice */ = {
-  name: 'mac-catalyst',
-  sdk: 'macosx',
-  targets: ['arm64-apple-ios15.0-macabi', 'x86_64-apple-ios15.0-macabi'],
-};
-
 /**
  * Builds ReactNativeHeaders.xcframework (R2, R5): a headers-only LIBRARY
  * xcframework (stub static archives — nothing embeds in apps) whose Headers
- * root carries every non-React namespace incl. the third-party deps
- * namespaces, plus module.modulemap with the plain per-namespace modules.
- * SPM serves its Headers automatically to dependents — no flags.
+ * root carries every non-React RN namespace, plus module.modulemap with the
+ * plain per-namespace modules. PURE-RN: the third-party deps namespaces ship
+ * in the ReactNativeDependenciesHeaders sidecar built by the deps prebuild
+ * (and by ensureHeadersLayout on the consumer side) — never here. SPM serves
+ * its Headers automatically to dependents — no flags.
  */
 function buildReactNativeHeadersXcframework(
   outDir /*: string */,
   plan /*: HeadersSpecPlan */,
-  depsHeaders /*: string */,
   rnRoot /*: string */,
   includeCatalyst /*: boolean */ = false,
   // Optional dir containing a `hermes/` namespace (Hermes public headers from
   // the hermes-ios tarball's destroot/include). Folded in as a textual
-  // namespace like folly/glog so `<hermes/...>` resolves without per-library
-  // wiring. null when unstaged — then `<hermes/...>` stays unavailable.
+  // namespace so `<hermes/...>` resolves without per-library wiring. null
+  // when unstaged — then `<hermes/...>` stays unavailable.
   hermesHeaders /*: ?string */ = null,
 ) /*: string */ {
   // ---- stage headers ----
   const stage = fs.mkdtempSync(path.join(outDir, '.rnh-stage-'));
   stageEntries(stage, plan.reactNativeHeaders, rnRoot);
-  for (const ns of plan.depsNamespaces) {
-    const src = path.join(depsHeaders, ns);
-    // Fail closed: a declared deps namespace (folly/glog/boost/...) missing
-    // from the staged ReactNativeDependencies headers means the artifact would
-    // ship WITHOUT those `<folly/...>`-style headers — a silently-broken
-    // ReactNativeHeaders.xcframework (consumers lose third-party header
-    // resolution). Refuse rather than emit it. Stage
-    // third-party/ReactNativeDependencies.xcframework/Headers (full prebuild or
-    // cache slot) before composing.
-    if (!fs.existsSync(src)) {
-      throw new Error(
-        `headers-compose: deps namespace '${ns}' missing under ${depsHeaders}. ` +
-          `ReactNativeDependencies headers are not staged — refusing to ship an ` +
-          `incomplete ReactNativeHeaders.xcframework.`,
-      );
-    }
-    execSync(`/bin/cp -Rc "${src}" "${path.join(stage, ns)}"`);
-  }
-  // Set equality with the deps artifact: a namespace dir present in the
-  // artifact but neither declared for relocation (DEPS_NAMESPACES) nor
-  // explicitly excluded (DEPS_NAMESPACES_NOT_RELOCATED — namespaces a real
-  // consumer pod vends itself, e.g. SocketRocket) means a new third-party dep
-  // was added upstream — fail closed so a decision is made deliberately.
-  const foundDepsDirs = fs
-    .readdirSync(depsHeaders, {withFileTypes: true})
-    .filter(e => e.isDirectory())
-    .map(e => String(e.name));
-  const undeclared = foundDepsDirs.filter(
-    d =>
-      !plan.depsNamespaces.includes(d) &&
-      !DEPS_NAMESPACES_NOT_RELOCATED.includes(d),
-  );
-  if (undeclared.length > 0) {
-    throw new Error(
-      `headers-compose: deps artifact ships undeclared namespace(s): ` +
-        `${undeclared.join(', ')}. Add them to DEPS_NAMESPACES (relocated) or ` +
-        `DEPS_NAMESPACES_NOT_RELOCATED (vended by a real pod) in headers-spec.js.`,
-    );
-  }
   // Hermes public headers (separate source from the deps namespaces — they
   // come from the hermes-ios tarball, not ReactNativeDependencies). Vend only
   // the `hermes/` namespace; `jsi/` is already provided elsewhere, so copying
@@ -264,54 +206,21 @@ function buildReactNativeHeadersXcframework(
     renderNamespaceModuleMap(plan.namespaceModules),
   );
 
-  // ---- stub static archives per slice ----
-  const work = fs.mkdtempSync(path.join(outDir, '.stub-work-'));
-  fs.writeFileSync(
-    path.join(work, 'stub.c'),
-    '// ReactNativeHeaders is headers-only; this stub satisfies xcframework tooling.\nstatic int RNHeadersStub __attribute__((unused)) = 0;\n',
-  );
+  // ---- compose (stub archives + create-xcframework) ----
   const slices = includeCatalyst
     ? [...DEFAULT_STUB_SLICES, CATALYST_STUB_SLICE]
     : DEFAULT_STUB_SLICES;
-  const libs = slices.map(slice => {
-    const sdkPath = execSync(`xcrun --sdk ${slice.sdk} --show-sdk-path`)
-      .toString()
-      .trim();
-    const thins = slice.targets.map((t, i) => {
-      const obj = path.join(work, `stub-${slice.name}-${i}.o`);
-      execSync(
-        `xcrun clang -c -target ${t} -isysroot "${sdkPath}" "${path.join(work, 'stub.c')}" -o "${obj}"`,
-      );
-      const lib = path.join(work, `stub-${slice.name}-${i}.a`);
-      execSync(`xcrun libtool -static -o "${lib}" "${obj}" 2>/dev/null`);
-      return lib;
-    });
-    const outLib = path.join(work, `libReactNativeHeaders-${slice.name}.a`);
-    if (thins.length === 1) {
-      fs.copyFileSync(thins[0], outLib);
-    } else {
-      execSync(
-        `xcrun lipo -create ${thins.map(l => `"${l}"`).join(' ')} -output "${outLib}"`,
-      );
-    }
-    return outLib;
-  });
-
-  // ---- compose ----
-  const outXcfw = path.join(outDir, 'ReactNativeHeaders.xcframework');
-  fs.rmSync(outXcfw, {recursive: true, force: true});
-  execSync(
-    `xcodebuild -create-xcframework ` +
-      libs.map(l => `-library "${l}" -headers "${stage}"`).join(' ') +
-      ` -output "${outXcfw}"`,
-    {stdio: 'pipe'},
+  const outXcfw = composeHeadersOnlyXcframework(
+    outDir,
+    'ReactNativeHeaders',
+    stage,
+    slices,
   );
   fs.rmSync(stage, {recursive: true, force: true});
-  fs.rmSync(work, {recursive: true, force: true});
   console.log(
     `headers-compose: ReactNativeHeaders.xcframework (${slices.map(s => s.name).join(', ')}) -> ${outXcfw} ` +
-      `(${plan.reactNativeHeaders.length} RN headers + deps ${plan.depsNamespaces.join(', ')}` +
-      `${hermesFolded ? ', hermes' : ''}; ` +
+      `(${plan.reactNativeHeaders.length} RN headers, pure-RN` +
+      `${hermesFolded ? ' + hermes' : ''}; ` +
       `${Object.keys(plan.namespaceModules).length} namespace modules)`,
   );
   return outXcfw;
@@ -321,20 +230,21 @@ function buildReactNativeHeadersXcframework(
  * Ensures the headers-spec layout exists at `outDir`, composed from the cache
  * slot's artifacts: clones React.xcframework (APFS clonefile), strips the
  * stale signature (R7 — production signs after compose), emits the spec
- * layout into every slice, and builds ReactNativeHeaders.xcframework from
- * the plan + the slot's deps headers.
+ * layout into every slice, builds the pure-RN ReactNativeHeaders.xcframework
+ * from the plan, and builds the ReactNativeDependenciesHeaders sidecar from
+ * the slot's deps headers.
  *
  * Skips when the freshness marker matches the source artifact (same
  * realpath + Info.plist mtime) unless `force`. Any consumer with a cache slot
- * gets composed artifacts automatically — no published ReactNativeHeaders
- * required.
+ * gets composed artifacts automatically — no published ReactNativeHeaders /
+ * ReactNativeDependenciesHeaders required.
  */
 function ensureHeadersLayout(
   artifactsDir /*: string */,
   rnRoot /*: string */,
   outDir /*: string */,
   force /*: boolean */ = false,
-) /*: {reactXcfw: string, headersXcfw: string} */ {
+) /*: {reactXcfw: string, headersXcfw: string, depsHeadersXcfw: string} */ {
   const sourceXcfw = fs.realpathSync(
     path.join(artifactsDir, 'React.xcframework'),
   );
@@ -353,6 +263,10 @@ function ensureHeadersLayout(
     : null;
   const reactXcfw = path.join(outDir, 'React.xcframework');
   const headersXcfw = path.join(outDir, 'ReactNativeHeaders.xcframework');
+  const depsHeadersXcfw = path.join(
+    outDir,
+    'ReactNativeDependenciesHeaders.xcframework',
+  );
   const markerPath = path.join(outDir, '.composed-from');
 
   const sourceStat = fs.statSync(path.join(sourceXcfw, 'Info.plist'));
@@ -364,10 +278,11 @@ function ensureHeadersLayout(
     !force &&
     fs.existsSync(reactXcfw) &&
     fs.existsSync(headersXcfw) &&
+    fs.existsSync(depsHeadersXcfw) &&
     fs.existsSync(markerPath) &&
     fs.readFileSync(markerPath, 'utf8') === marker
   ) {
-    return {reactXcfw, headersXcfw};
+    return {reactXcfw, headersXcfw, depsHeadersXcfw};
   }
 
   console.log(
@@ -387,13 +302,20 @@ function ensureHeadersLayout(
   buildReactNativeHeadersXcframework(
     outDir,
     plan,
-    depsHeaders,
     rnRoot,
     false,
     hermesHeaders,
   );
+  // The deps sidecar (like ReactNativeHeaders here) skips the catalyst slice
+  // on the consumer repackage path to stay fast.
+  buildDepsHeadersXcframework(
+    outDir,
+    depsHeaders,
+    plan.depsNamespaces,
+    DEFAULT_STUB_SLICES,
+  );
   fs.writeFileSync(markerPath, marker);
-  return {reactXcfw, headersXcfw};
+  return {reactXcfw, headersXcfw, depsHeadersXcfw};
 }
 
 module.exports = {
diff --git a/packages/react-native/scripts/ios-prebuild/headers-inventory.js b/packages/react-native/scripts/ios-prebuild/headers-inventory.js
index 980c447c5092..aac50945009c 100644
--- a/packages/react-native/scripts/ios-prebuild/headers-inventory.js
+++ b/packages/react-native/scripts/ios-prebuild/headers-inventory.js
@@ -31,10 +31,7 @@
 
 const {getHeaderFilesFromPodspecs} = require('./headers');
 // headers-spec.js requires only fs/path, so this cannot cycle.
-const {
-  DEPS_NAMESPACES,
-  DEPS_NAMESPACES_NOT_RELOCATED,
-} = require('./headers-spec');
+const {DEPS_NAMESPACES} = require('./headers-spec');
 const fs = require('fs');
 const path = require('path');
 
@@ -77,13 +74,10 @@ type HeaderEntry = {
 */
 // Third-party C++ libraries that RN's public headers re-expose (Tier 3 of the
 // modularization doc). Keyed by the first include-path segment. Single source
-// of truth: the spec's DEPS_NAMESPACES (the namespaces relocated into
-// ReactNativeHeaders) — a new third-party dep is declared ONCE and both the
-// include classifier and the compose step follow.
-const THIRD_PARTY_LIBS /*: Set<string> */ = new Set([
-  ...DEPS_NAMESPACES,
-  ...DEPS_NAMESPACES_NOT_RELOCATED,
-]);
+// of truth: the spec's DEPS_NAMESPACES (the ReactNativeDependenciesHeaders
+// sidecar's namespace set) — a new third-party dep is declared ONCE and the
+// include classifier, the sidecar emitter, and the headers gate all follow.
+const THIRD_PARTY_LIBS /*: Set<string> */ = new Set(DEPS_NAMESPACES);
 
 // Apple SDK / platform include roots (first path segment). Includes resolving
 // here are "system": always modular or always available, never our problem.
diff --git a/packages/react-native/scripts/ios-prebuild/headers-spec.js b/packages/react-native/scripts/ios-prebuild/headers-spec.js
index 62afc12a7cb4..a804d3142787 100644
--- a/packages/react-native/scripts/ios-prebuild/headers-spec.js
+++ b/packages/react-native/scripts/ios-prebuild/headers-spec.js
@@ -25,12 +25,14 @@
  *     would require case-folding `react.framework` → `React.framework`, which
  *     only works on case-insensitive filesystems; the header-search-path route
  *     is exact and works everywhere.
- * R2. Every other namespace (incl. `react/`) ships in ONE headers-only library
- *     xcframework ("ReactNativeHeaders"), namespace dirs at its Headers root,
- *     INCLUDING the third-party deps namespaces (folly/glog/boost/fmt/
- *     double-conversion/fast_float, sourced from the deps artifact) — making
- *     ReactNativeDependencies binary-only. Served by exact header-search-path
- *     lookup, so resolution is filesystem-case-independent.
+ * R2. Every other RN namespace (incl. `react/`) ships in ONE headers-only
+ *     library xcframework ("ReactNativeHeaders"), namespace dirs at its
+ *     Headers root. PURE-RN: the third-party deps namespaces (DEPS_NAMESPACES)
+ *     are NOT here — they ship in the ReactNativeDependenciesHeaders sidecar
+ *     built by the deps prebuild from its own artifact headers, so every
+ *     namespace has exactly ONE physical home (the SocketRocket dual-copy
+ *     regression class is structurally impossible). Both are served by exact
+ *     header-search-path lookup, so resolution is filesystem-case-independent.
  * R3. NO include rewriting anywhere — source headers are byte-identical to
  *     the repo (content authority = source files; layout authority = this
  *     spec). Consumers compile unchanged except bare-form angle includes
@@ -109,10 +111,15 @@ export type HeadersSpecPlan = {
 };
 */
 
-// R2: third-party namespaces relocated from the deps artifact. Kept in exact
-// sync with the artifact's Headers/ dirs — compose fails closed on a missing
-// OR an undeclared namespace, and the include classifier
-// (headers-inventory.js THIRD_PARTY_LIBS) derives from this same list.
+// R2: the third-party deps namespaces — the exact contents of the
+// ReactNativeDependenciesHeaders sidecar, and the exact set of namespace dirs
+// the deps artifact's Headers/ ships. The sidecar emitter fails closed on a
+// missing OR an undeclared namespace (set equality), the headers gate asserts
+// these stay ABSENT from ReactNativeHeaders (one physical home per
+// namespace — relocated copies collided with real pods' own headers: the
+// SocketRocket duplicate-@interface / poisoned-module-graph Expo regression,
+// 2026-07-03), and the include classifier (headers-inventory.js
+// THIRD_PARTY_LIBS) derives from this same list.
 const DEPS_NAMESPACES = [
   'folly',
   'glog',
@@ -120,20 +127,9 @@ const DEPS_NAMESPACES = [
   'fmt',
   'double-conversion',
   'fast_float',
+  'SocketRocket',
 ];
 
-// Namespaces the deps artifact ships but which must NOT be relocated into
-// ReactNativeHeaders: a REAL CocoaPods pod of the same name exists in consumer
-// graphs and vends these headers itself (with its own module). Relocating
-// textual copies puts them on every pod's HEADER_SEARCH_PATHS via the
-// flattened React-Core-prebuilt/Headers and collides with the pod's own
-// headers — duplicate @interface definitions compiling the SocketRocket pod,
-// and a poisoned module graph in use_frameworks/explicit-modules apps
-// (Expo regression, 2026-07-03). The compose set-equality guard treats these
-// as declared (so only genuinely NEW namespaces fail closed), and the headers
-// gate asserts they stay ABSENT from the artifact.
-const DEPS_NAMESPACES_NOT_RELOCATED = ['SocketRocket'];
-
 // R4/R5 umbrella exclusion: C extern-inline definitions.
 const EXTERN_INLINE_RE /*: RegExp */ =
   /\b(RCT_EXTERN\s+inline|extern\s+inline)\b/;
@@ -469,7 +465,6 @@ function renderNamespaceModuleMap(
 
 module.exports = {
   planFromInventory,
-  DEPS_NAMESPACES_NOT_RELOCATED,
   renderReactModuleMap,
   renderUmbrellaHeader,
   renderNamespaceModuleMap,
diff --git a/packages/react-native/scripts/ios-prebuild/headers-verify.js b/packages/react-native/scripts/ios-prebuild/headers-verify.js
index a18143bb6262..79bebc800348 100644
--- a/packages/react-native/scripts/ios-prebuild/headers-verify.js
+++ b/packages/react-native/scripts/ios-prebuild/headers-verify.js
@@ -39,7 +39,6 @@
 
 const {computeInventory} = require('./headers-inventory');
 const {
-  DEPS_NAMESPACES_NOT_RELOCATED,
   planFromInventory,
   renderNamespaceModuleMap,
   renderReactModuleMap,
@@ -227,18 +226,16 @@ function verifyStructural(
       `R10 umbrella ${u.relPath}`,
     );
   }
+  // ReactNativeHeaders is PURE-RN: every deps namespace must stay ABSENT.
+  // They ship in the ReactNativeDependenciesHeaders sidecar (one physical
+  // home per namespace) — relocated copies collide with the real pods' own
+  // headers (SocketRocket / Expo use_frameworks regression, 2026-07-03).
   for (const ns of plan.depsNamespaces) {
-    if (!fs.existsSync(path.join(rnhHeaders, ns))) {
-      throw new Error(`deps namespace missing from artifact: ${ns}`);
-    }
-  }
-  // Excluded namespaces must stay ABSENT: relocating them collides with the
-  // real pod's own headers (SocketRocket / Expo use_frameworks regression).
-  for (const ns of DEPS_NAMESPACES_NOT_RELOCATED) {
     if (fs.existsSync(path.join(rnhHeaders, ns))) {
       throw new Error(
-        `excluded deps namespace '${ns}' found in the artifact — it must NOT ` +
-          `be relocated (a real pod vends it; textual copies collide).`,
+        `deps namespace '${ns}' found in ReactNativeHeaders — it must NOT be ` +
+          `relocated (it ships in ReactNativeDependenciesHeaders; textual ` +
+          `copies collide with the real pods' headers).`,
       );
     }
   }
@@ -319,6 +316,7 @@ function runCompileGates(
   plan /*: HeadersSpecPlan */,
   reactSlice /*: string */,
   rnhHeaders /*: string */,
+  depsHeaders /*: string */,
 ) /*: void */ {
   const sdk = execFileSync(
     'xcrun',
@@ -327,6 +325,10 @@ function runCompileGates(
   ).trim();
   const tmp = fs.mkdtempSync(path.join(os.tmpdir(), 'headers-verify-'));
   try {
+    // ReactNativeHeaders is pure-RN, so the deps headers (folly/glog/... —
+    // reached textually from RN's public headers) come from the deps
+    // artifact's Headers dir, exactly as consumers get them from the
+    // ReactNativeDependencies pod / ReactNativeDependenciesHeaders sidecar.
     const common = [
       '-fsyntax-only',
       '-target',
@@ -337,6 +339,8 @@ function runCompileGates(
       reactSlice,
       '-I',
       rnhHeaders,
+      '-I',
+      depsHeaders,
     ];
 
     const objc = path.join(tmp, 'gate-modules.m');
@@ -394,6 +398,8 @@ function runCompileGates(
         reactSlice,
         '-I',
         rnhHeaders,
+        '-I',
+        depsHeaders,
         swift,
       ],
       'Swift gate (import React + RCTBridge.moduleRegistry)',
@@ -459,7 +465,23 @@ function main(argv /*:: ?: Array<string> */) /*: void */ {
   if (args.skipCompile) {
     log('compile gates skipped (--skip-compile).');
   } else {
-    runCompileGates(plan, reactSlice, rnhHeaders);
+    // ReactNativeHeaders is pure-RN — the compile gates additionally need the
+    // deps headers, served from the staged deps artifact (the same content
+    // the ReactNativeDependenciesHeaders sidecar ships).
+    const depsHeaders = path.join(
+      RN_ROOT,
+      'third-party',
+      'ReactNativeDependencies.xcframework',
+      'Headers',
+    );
+    if (!fs.existsSync(depsHeaders)) {
+      throw new Error(
+        `deps headers missing at ${depsHeaders} — stage the ` +
+          `ReactNativeDependencies artifact before running the compile gates ` +
+          `(or pass --skip-compile).`,
+      );
+    }
+    runCompileGates(plan, reactSlice, rnhHeaders, depsHeaders);
   }
   log('ALL GATES PASSED.');
 }
diff --git a/packages/react-native/scripts/ios-prebuild/headers-xcframework.js b/packages/react-native/scripts/ios-prebuild/headers-xcframework.js
new file mode 100644
index 000000000000..461bbc6c3949
--- /dev/null
+++ b/packages/react-native/scripts/ios-prebuild/headers-xcframework.js
@@ -0,0 +1,241 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @flow
+ * @format
+ */
+
+/**
+ * Headers-only xcframework emitter — the shared recipe behind
+ * ReactNativeHeaders.xcframework (headers-compose.js) and the
+ * ReactNativeDependenciesHeaders.xcframework sidecar (the deps prebuild's
+ * compose-framework.js). A headers-only artifact is a LIBRARY-type
+ * xcframework: stub static archives (nothing embeds in apps) paired with a
+ * staged Headers dir. The per-slice Headers/ layout and the Info.plist
+ * `HeadersPath` key — what makes SwiftPM auto-serve the headers with zero
+ * flags — are produced by `xcodebuild -create-xcframework -library ...
+ * -headers ...` itself and are never hand-written (framework-type entries
+ * hard-reject `HeadersPath`; verified 2026-07-04).
+ *
+ * This module must stay dependency-light (fs/path/child_process only): the
+ * deps prebuild under scripts/releases requires it across the package
+ * boundary.
+ */
+
+const {execSync} = require('child_process');
+const fs = require('fs');
+const path = require('path');
+
+/*::
+export type StubSlice = {
+  name: string, // human label
+  sdk: string, // xcrun --sdk name
+  targets: Array<string>, // clang -target triples (lipo'd when > 1)
+};
+*/
+
+const DEFAULT_STUB_SLICES /*: Array<StubSlice> */ = [
+  {name: 'ios', sdk: 'iphoneos', targets: ['arm64-apple-ios15.0']},
+  {
+    name: 'ios-simulator',
+    sdk: 'iphonesimulator',
+    targets: [
+      'arm64-apple-ios15.0-simulator',
+      'x86_64-apple-ios15.0-simulator',
+    ],
+  },
+];
+
+// Mac Catalyst slice — used by the real compose (the cached-artifact
+// repackage path skips it to stay fast; React.xcframework carries it).
+const CATALYST_STUB_SLICE /*: StubSlice */ = {
+  name: 'mac-catalyst',
+  sdk: 'macosx',
+  targets: ['arm64-apple-ios15.0-macabi', 'x86_64-apple-ios15.0-macabi'],
+};
+
+// SupportedPlatform(+variant) from an xcframework Info.plist -> stub recipe.
+// The min OS version in the triple only shapes the stub object file; slice
+// identity (what create-xcframework groups by) comes from platform + variant
+// + archs.
+const PLATFORM_STUB_RECIPES /*: {
+  [key: string]: {sdk: string, os: string, suffix: string},
+} */ = {
+  ios: {sdk: 'iphoneos', os: 'ios15.0', suffix: ''},
+  'ios-simulator': {
+    sdk: 'iphonesimulator',
+    os: 'ios15.0',
+    suffix: '-simulator',
+  },
+  'ios-maccatalyst': {sdk: 'macosx', os: 'ios15.0', suffix: '-macabi'},
+  macos: {sdk: 'macosx', os: 'macosx11.0', suffix: ''},
+  tvos: {sdk: 'appletvos', os: 'tvos15.1', suffix: ''},
+  'tvos-simulator': {
+    sdk: 'appletvsimulator',
+    os: 'tvos15.1',
+    suffix: '-simulator',
+  },
+  xros: {sdk: 'xros', os: 'xros1.0', suffix: ''},
+  'xros-simulator': {sdk: 'xrsimulator', os: 'xros1.0', suffix: '-simulator'},
+};
+
+/**
+ * Derives stub slices matching an existing (binary) xcframework's slice set,
+ * so a headers-only sidecar resolves for every platform the binary does.
+ */
+function stubSlicesFromXcframework(
+  xcfwPath /*: string */,
+) /*: Array<StubSlice> */ {
+  const plist = JSON.parse(
+    execSync(
+      `plutil -convert json -o - "${path.join(xcfwPath, 'Info.plist')}"`,
+    ).toString(),
+  );
+  return plist.AvailableLibraries.map(lib => {
+    const key =
+      lib.SupportedPlatformVariant != null
+        ? `${lib.SupportedPlatform}-${lib.SupportedPlatformVariant}`
+        : lib.SupportedPlatform;
+    const recipe = PLATFORM_STUB_RECIPES[key];
+    if (recipe == null) {
+      throw new Error(
+        `headers-xcframework: no stub recipe for slice '${key}' of ` +
+          `${xcfwPath}. Add it to PLATFORM_STUB_RECIPES.`,
+      );
+    }
+    return {
+      name: key,
+      sdk: recipe.sdk,
+      targets: lib.SupportedArchitectures.map(
+        a => `${a}-apple-${recipe.os}${recipe.suffix}`,
+      ),
+    };
+  });
+}
+
+/**
+ * Composes `<name>.xcframework` under `outDir` from an already-populated
+ * Headers stage dir: one stub static archive per slice, then
+ * `xcodebuild -create-xcframework` pairing every archive with the stage.
+ * The caller owns (and cleans) the stage dir.
+ */
+function composeHeadersOnlyXcframework(
+  outDir /*: string */,
+  name /*: string */,
+  stage /*: string */,
+  slices /*: Array<StubSlice> */,
+) /*: string */ {
+  const work = fs.mkdtempSync(path.join(outDir, '.stub-work-'));
+  fs.writeFileSync(
+    path.join(work, 'stub.c'),
+    `// ${name} is headers-only; this stub satisfies xcframework tooling.\n` +
+      `static int ${name}Stub __attribute__((unused)) = 0;\n`,
+  );
+  const libs = slices.map(slice => {
+    const sdkPath = execSync(`xcrun --sdk ${slice.sdk} --show-sdk-path`)
+      .toString()
+      .trim();
+    const thins = slice.targets.map((t, i) => {
+      const obj = path.join(work, `stub-${slice.name}-${i}.o`);
+      execSync(
+        `xcrun clang -c -target ${t} -isysroot "${sdkPath}" "${path.join(work, 'stub.c')}" -o "${obj}"`,
+      );
+      const lib = path.join(work, `stub-${slice.name}-${i}.a`);
+      execSync(`xcrun libtool -static -o "${lib}" "${obj}" 2>/dev/null`);
+      return lib;
+    });
+    const outLib = path.join(work, `lib${name}-${slice.name}.a`);
+    if (thins.length === 1) {
+      fs.copyFileSync(thins[0], outLib);
+    } else {
+      execSync(
+        `xcrun lipo -create ${thins.map(l => `"${l}"`).join(' ')} -output "${outLib}"`,
+      );
+    }
+    return outLib;
+  });
+
+  const outXcfw = path.join(outDir, `${name}.xcframework`);
+  fs.rmSync(outXcfw, {recursive: true, force: true});
+  execSync(
+    `xcodebuild -create-xcframework ` +
+      libs.map(l => `-library "${l}" -headers "${stage}"`).join(' ') +
+      ` -output "${outXcfw}"`,
+    {stdio: 'pipe'},
+  );
+  fs.rmSync(work, {recursive: true, force: true});
+  return outXcfw;
+}
+
+const DEPS_HEADERS_XCFRAMEWORK_NAME = 'ReactNativeDependenciesHeaders';
+
+/**
+ * Builds ReactNativeDependenciesHeaders.xcframework: the headers-only sidecar
+ * serving the third-party deps namespaces (folly/glog/boost/fmt/
+ * double-conversion/fast_float/SocketRocket). The binary
+ * ReactNativeDependencies.xcframework is FRAMEWORK-type, so its root Headers/
+ * dir is invisible to SwiftPM — this LIBRARY-type sidecar is what makes the
+ * deps headers auto-served, keeping ReactNativeHeaders pure-RN.
+ *
+ * Set-equality with `namespaces` (headers-spec.js DEPS_NAMESPACES) is
+ * enforced fail-closed in BOTH directions: a declared namespace missing from
+ * `depsHeaders` would ship a silently-broken sidecar; an undeclared dir means
+ * a new third-party dep was added without a spec decision.
+ */
+function buildDepsHeadersXcframework(
+  outDir /*: string */,
+  depsHeaders /*: string */,
+  namespaces /*: Array<string> */,
+  slices /*: Array<StubSlice> */,
+) /*: string */ {
+  const found = fs
+    .readdirSync(depsHeaders, {withFileTypes: true})
+    .filter(e => e.isDirectory())
+    .map(e => String(e.name));
+  const missing = namespaces.filter(ns => !found.includes(ns));
+  const undeclared = found.filter(d => !namespaces.includes(d));
+  if (missing.length > 0 || undeclared.length > 0) {
+    throw new Error(
+      `headers-xcframework: deps namespaces out of sync with the spec.\n` +
+        (missing.length > 0
+          ? `  missing from ${depsHeaders}: ${missing.join(', ')}\n`
+          : '') +
+        (undeclared.length > 0
+          ? `  undeclared in DEPS_NAMESPACES (headers-spec.js): ${undeclared.join(', ')}\n`
+          : '') +
+        `Declare new deps deliberately — the sidecar and the spec must agree.`,
+    );
+  }
+
+  const stage = fs.mkdtempSync(path.join(outDir, '.deps-headers-stage-'));
+  for (const ns of namespaces) {
+    execSync(
+      `/bin/cp -Rc "${path.join(depsHeaders, ns)}" "${path.join(stage, ns)}"`,
+    );
+  }
+  const outXcfw = composeHeadersOnlyXcframework(
+    outDir,
+    DEPS_HEADERS_XCFRAMEWORK_NAME,
+    stage,
+    slices,
+  );
+  fs.rmSync(stage, {recursive: true, force: true});
+  console.log(
+    `headers-xcframework: ${DEPS_HEADERS_XCFRAMEWORK_NAME}.xcframework ` +
+      `(${slices.map(s => s.name).join(', ')}) -> ${outXcfw} ` +
+      `(namespaces: ${namespaces.join(', ')})`,
+  );
+  return outXcfw;
+}
+
+module.exports = {
+  CATALYST_STUB_SLICE,
+  DEFAULT_STUB_SLICES,
+  DEPS_HEADERS_XCFRAMEWORK_NAME,
+  buildDepsHeadersXcframework,
+  composeHeadersOnlyXcframework,
+  stubSlicesFromXcframework,
+};
diff --git a/packages/react-native/scripts/ios-prebuild/reactNativeDependencies.js b/packages/react-native/scripts/ios-prebuild/reactNativeDependencies.js
index 43c40d9e51bd..c58ae0fc37d8 100644
--- a/packages/react-native/scripts/ios-prebuild/reactNativeDependencies.js
+++ b/packages/react-native/scripts/ios-prebuild/reactNativeDependencies.js
@@ -92,6 +92,28 @@ async function prepareReactNativeDependenciesArtifactsAsync(
     stdio: 'inherit',
   });
 
+  // The headers-only ReactNativeDependenciesHeaders.xcframework sidecar ships
+  // alongside the binary in the same tarball — it is what serves the deps
+  // namespaces to SwiftPM (the binary is framework-type; its root Headers/ is
+  // invisible to binaryTargets). Absent only in pre-sidecar tarballs (pinned
+  // RN_DEP_VERSION): CocoaPods still works (the pod flattens the binary's
+  // root Headers/), SwiftPM consumers regain it via ensureHeadersLayout.
+  const headersSidecarSource = path.join(
+    path.dirname(xcframeworkSource),
+    'ReactNativeDependenciesHeaders.xcframework',
+  );
+  if (fs.existsSync(headersSidecarSource)) {
+    execSync(`cp -R "${headersSidecarSource}" "${artifactsPath}"`, {
+      stdio: 'inherit',
+    });
+  } else {
+    dependencyLog(
+      'ReactNativeDependenciesHeaders.xcframework not present in the tarball ' +
+        '(pre-sidecar artifact) — continuing with the binary xcframework only.',
+      'warning',
+    );
+  }
+
   // Delete the tarball after extraction
   if (!process.env.HERMES_ENGINE_TARBALL_PATH) {
     fs.unlinkSync(localPath);
diff --git a/packages/react-native/scripts/ios-prebuild/xcframework.js b/packages/react-native/scripts/ios-prebuild/xcframework.js
index f021edbf68cc..c7cc2fd3b347 100644
--- a/packages/react-native/scripts/ios-prebuild/xcframework.js
+++ b/packages/react-native/scripts/ios-prebuild/xcframework.js
@@ -86,22 +86,19 @@ function buildXCFrameworks(
     computeSpecPlan,
     emitReactFrameworkHeaders,
   } = require('./headers-compose');
-  const depsHeaders = path.join(
-    rootFolder,
-    'third-party',
-    'ReactNativeDependencies.xcframework',
-    'Headers',
-  );
   const plan = computeSpecPlan(rootFolder);
   emitReactFrameworkHeaders(outputPath, plan, rootFolder);
+  // ReactNativeHeaders is PURE-RN — the third-party deps namespaces ship in
+  // the ReactNativeDependenciesHeaders sidecar built by the deps prebuild
+  // (scripts/releases/ios-prebuild), so the core compose no longer needs the
+  // deps artifact's headers.
   // NOTE: Hermes public headers (`<hermes/...>`) are folded into
   // ReactNativeHeaders on the consumer side by ensureHeadersLayout. When this
   // publish path is productionized, pass the prebuild's hermes destroot/include
-  // as the 6th arg so the PUBLISHED ReactNativeHeaders carries hermes too.
+  // as the 5th arg so the PUBLISHED ReactNativeHeaders carries hermes too.
   const headersXcfw = buildReactNativeHeadersXcframework(
     path.dirname(outputPath),
     plan,
-    depsHeaders,
     rootFolder,
     true, // include the mac-catalyst slice in the real compose
   );
diff --git a/packages/react-native/scripts/react_native_pods.rb b/packages/react-native/scripts/react_native_pods.rb
index 4214e23b20da..3b6d3142b38e 100644
--- a/packages/react-native/scripts/react_native_pods.rb
+++ b/packages/react-native/scripts/react_native_pods.rb
@@ -621,6 +621,15 @@ def react_native_post_install(
     ReactNativeCoreUtils.configure_aggregate_xcconfig(installer)
   end
 
+  if !ReactNativeDependenciesUtils.build_react_native_deps_from_source()
+    # Prebuilt-deps mode: make the deps artifact headers (folly/glog/...)
+    # resolvable from the aggregate and every pod target, mirroring the rncore
+    # injection above. ReactNativeHeaders is pure-RN, so the flattened
+    # ReactNativeDependencies/Headers dir is the single global home of the
+    # third-party namespaces (see scripts/cocoapods/__docs__/prebuilt-deps.md).
+    ReactNativeDependenciesUtils.configure_aggregate_xcconfig(installer)
+  end
+
   SPM.apply_on_post_install(installer)
 
   if privacy_file_aggregation_enabled
diff --git a/scripts/releases/ios-prebuild/compose-framework.js b/scripts/releases/ios-prebuild/compose-framework.js
index fd0e1287d1f3..12f026148550 100644
--- a/scripts/releases/ios-prebuild/compose-framework.js
+++ b/scripts/releases/ios-prebuild/compose-framework.js
@@ -8,6 +8,15 @@
  * @format
  */
 
+// Shared with the core prebuild (kept dependency-light for this cross-package
+// require): the headers-only xcframework recipe and the deps namespace spec.
+const {
+  DEPS_NAMESPACES,
+} = require('../../../packages/react-native/scripts/ios-prebuild/headers-spec');
+const {
+  buildDepsHeadersXcframework,
+  stubSlicesFromXcframework,
+} = require('../../../packages/react-native/scripts/ios-prebuild/headers-xcframework');
 const {HEADERS_FOLDER, TARGET_FOLDER} = require('./constants');
 const {execSync} = require('child_process');
 const fs = require('fs');
@@ -70,8 +79,23 @@ async function createFramework(
   // Copy headers to the framework - start by building the Header folder
   copyHeaders(scheme, dependencies, rootFolder);
 
+  // Emit the headers-only ReactNativeDependenciesHeaders.xcframework sidecar
+  // from the root Headers/ just assembled. The binary xcframework is
+  // FRAMEWORK-type, so its root Headers/ is invisible to SwiftPM
+  // (`HeadersPath` is rejected on framework entries) — the LIBRARY-type
+  // sidecar is what auto-serves the deps namespaces. Root Headers/ is
+  // slice-uniform (copied once after create-xcframework), so the sidecar
+  // stages it per slice, with slice parity derived from the binary artifact.
+  const headersXcfw = buildDepsHeadersXcframework(
+    rootFolder,
+    path.join(output, 'Headers'),
+    DEPS_NAMESPACES,
+    stubSlicesFromXcframework(output),
+  );
+
   if (identity) {
     signXCFramework(identity, output);
+    signXCFramework(identity, headersXcfw);
   }
 }