diff --git a/packages/react-native/scripts/swiftpm/__tests__/prepare-app-utils-test.js b/packages/react-native/scripts/swiftpm/__tests__/prepare-app-utils-test.js
index a2be2a740111..6df8c34434cc 100644
--- a/packages/react-native/scripts/swiftpm/__tests__/prepare-app-utils-test.js
+++ b/packages/react-native/scripts/swiftpm/__tests__/prepare-app-utils-test.js
@@ -11,14 +11,29 @@
 'use strict';
 
 const {
+  configureAppForSwift,
   findXcodeProjectDirectory,
   runIosPrebuild,
   runPodDeintegrate,
+  setBuildFromSource,
 } = require('../prepare-app-utils');
 
 // Mock child_process module
 jest.mock('child_process');
 
+// Mock fs module
+jest.mock('fs');
+
+// Mock path module for absolute paths
+jest.mock('path', () => {
+  const actualPath = jest.requireActual('path');
+  return {
+    ...actualPath,
+    join: jest.fn((...args) => args.join('/')),
+    relative: jest.fn((from, to) => to.replace(from + '/', '')),
+  };
+});
+
 // Mock console methods - disable React Native's strict console checking
 const originalConsole = global.console;
 
@@ -175,6 +190,237 @@ describe('findXcodeProjectDirectory', () => {
   });
 });
 
+describe('setBuildFromSource', () => {
+  let mockFs;
+  let mockPath;
+  let mockConsoleLog;
+  let mockConsoleWarn;
+
+  beforeEach(() => {
+    // Setup mocks
+    mockFs = require('fs');
+    mockPath = require('path');
+    mockConsoleLog = console.log;
+    mockConsoleWarn = console.warn;
+
+    // Clear and reset all mocks completely
+    jest.clearAllMocks();
+    jest.resetAllMocks();
+
+    // Set up fresh mock implementations
+    mockFs.existsSync = jest.fn();
+    mockFs.readFileSync = jest.fn();
+    mockFs.writeFileSync = jest.fn();
+
+    // Mock path.join to return realistic paths
+    mockPath.join.mockImplementation((...args) => args.join('/'));
+  });
+
+  it('should update BUILD_FROM_SOURCE from false to true successfully', async () => {
+    // Setup
+    const reactNativePath = '/path/to/react-native';
+    const mockPackageSwiftContent = `
+// Package.swift
+import PackageDescription
+
+let BUILD_FROM_SOURCE = false
+
+let package = Package(
+    name: "ReactNative",
+    platforms: [.iOS(.v13)],
+    // rest of package
+)
+`;
+
+    const expectedUpdatedContent = `
+// Package.swift
+import PackageDescription
+
+let BUILD_FROM_SOURCE = true
+
+let package = Package(
+    name: "ReactNative",
+    platforms: [.iOS(.v13)],
+    // rest of package
+)
+`;
+
+    mockFs.existsSync.mockReturnValue(true);
+    mockFs.readFileSync.mockReturnValue(mockPackageSwiftContent);
+    mockFs.writeFileSync.mockImplementation(() => {});
+
+    // Execute
+    await setBuildFromSource(reactNativePath);
+
+    // Assert
+    expect(mockFs.existsSync).toHaveBeenCalledWith(
+      '/path/to/react-native/Package.swift',
+    );
+    expect(mockFs.readFileSync).toHaveBeenCalledWith(
+      '/path/to/react-native/Package.swift',
+      'utf8',
+    );
+    expect(mockFs.writeFileSync).toHaveBeenCalledWith(
+      '/path/to/react-native/Package.swift',
+      expectedUpdatedContent,
+      'utf8',
+    );
+    expect(mockConsoleLog).toHaveBeenCalledWith(
+      'Updating BUILD_FROM_SOURCE in: /path/to/react-native/Package.swift',
+    );
+    expect(mockConsoleLog).toHaveBeenCalledWith(
+      '✓ BUILD_FROM_SOURCE set to true in Package.swift',
+    );
+    expect(mockConsoleWarn).not.toHaveBeenCalled();
+  });
+
+  it('should handle when BUILD_FROM_SOURCE is already true', async () => {
+    // Setup
+    const reactNativePath = '/path/to/react-native';
+    const mockPackageSwiftContent = `
+// Package.swift
+import PackageDescription
+
+let BUILD_FROM_SOURCE = true
+
+let package = Package(
+    name: "ReactNative",
+    platforms: [.iOS(.v13)],
+    // rest of package
+)
+`;
+
+    mockFs.existsSync.mockReturnValue(true);
+    mockFs.readFileSync.mockReturnValue(mockPackageSwiftContent);
+    mockFs.writeFileSync.mockImplementation(() => {});
+
+    // Execute
+    await setBuildFromSource(reactNativePath);
+
+    // Assert
+    expect(mockFs.existsSync).toHaveBeenCalledWith(
+      '/path/to/react-native/Package.swift',
+    );
+    expect(mockFs.readFileSync).toHaveBeenCalledWith(
+      '/path/to/react-native/Package.swift',
+      'utf8',
+    );
+    expect(mockFs.writeFileSync).not.toHaveBeenCalled(); // Should not write when already true
+    expect(mockConsoleLog).toHaveBeenCalledWith(
+      'Updating BUILD_FROM_SOURCE in: /path/to/react-native/Package.swift',
+    );
+    expect(mockConsoleLog).toHaveBeenCalledWith(
+      '✓ BUILD_FROM_SOURCE is already set to true in Package.swift',
+    );
+    expect(mockConsoleWarn).not.toHaveBeenCalled();
+  });
+
+  it('should warn when BUILD_FROM_SOURCE declaration is not found', async () => {
+    // Setup
+    const reactNativePath = '/path/to/react-native';
+    const mockPackageSwiftContent = `
+// Package.swift
+import PackageDescription
+
+let package = Package(
+    name: "ReactNative",
+    platforms: [.iOS(.v13)],
+    // rest of package without BUILD_FROM_SOURCE
+)
+`;
+
+    mockFs.existsSync.mockReturnValue(true);
+    mockFs.readFileSync.mockReturnValue(mockPackageSwiftContent);
+    mockFs.writeFileSync.mockImplementation(() => {});
+
+    // Execute
+    await setBuildFromSource(reactNativePath);
+
+    // Assert
+    expect(mockFs.existsSync).toHaveBeenCalledWith(
+      '/path/to/react-native/Package.swift',
+    );
+    expect(mockFs.readFileSync).toHaveBeenCalledWith(
+      '/path/to/react-native/Package.swift',
+      'utf8',
+    );
+    expect(mockFs.writeFileSync).not.toHaveBeenCalled(); // Should not write when declaration not found
+    expect(mockConsoleLog).toHaveBeenCalledWith(
+      'Updating BUILD_FROM_SOURCE in: /path/to/react-native/Package.swift',
+    );
+    expect(mockConsoleWarn).toHaveBeenCalledWith(
+      '⚠️  BUILD_FROM_SOURCE declaration not found in Package.swift',
+    );
+  });
+
+  it('should throw error when Package.swift does not exist', async () => {
+    // Setup
+    const reactNativePath = '/path/to/react-native';
+
+    mockFs.existsSync.mockReturnValue(false);
+
+    // Execute & Assert
+    await expect(setBuildFromSource(reactNativePath)).rejects.toThrow(
+      'Package.swift not found at: /path/to/react-native/Package.swift',
+    );
+
+    expect(mockFs.existsSync).toHaveBeenCalledWith(
+      '/path/to/react-native/Package.swift',
+    );
+    expect(mockFs.readFileSync).not.toHaveBeenCalled();
+    expect(mockFs.writeFileSync).not.toHaveBeenCalled();
+    expect(mockConsoleLog).not.toHaveBeenCalled();
+  });
+
+  it('should handle multiple BUILD_FROM_SOURCE occurrences', async () => {
+    // Setup
+    const reactNativePath = '/path/to/react-native';
+    const mockPackageSwiftContent = `
+// Package.swift
+import PackageDescription
+
+let BUILD_FROM_SOURCE = false
+// Some comment about BUILD_FROM_SOURCE = false
+let anotherVar = "BUILD_FROM_SOURCE = false in string"
+
+let package = Package(
+    name: "ReactNative",
+    platforms: [.iOS(.v13)],
+    // Another BUILD_FROM_SOURCE = false comment
+)
+`;
+
+    const expectedUpdatedContent = `
+// Package.swift
+import PackageDescription
+
+let BUILD_FROM_SOURCE = true
+// Some comment about BUILD_FROM_SOURCE = false
+let anotherVar = "BUILD_FROM_SOURCE = false in string"
+
+let package = Package(
+    name: "ReactNative",
+    platforms: [.iOS(.v13)],
+    // Another BUILD_FROM_SOURCE = false comment
+)
+`;
+
+    mockFs.existsSync.mockReturnValue(true);
+    mockFs.readFileSync.mockReturnValue(mockPackageSwiftContent);
+    mockFs.writeFileSync.mockImplementation(() => {});
+
+    // Execute
+    await setBuildFromSource(reactNativePath);
+
+    // Assert - should replace only the declaration, not comments or strings
+    expect(mockFs.writeFileSync).toHaveBeenCalledWith(
+      '/path/to/react-native/Package.swift',
+      expectedUpdatedContent,
+      'utf8',
+    );
+  });
+});
+
 describe('runIosPrebuild', () => {
   let mockExecSync;
   let mockConsoleLog;
@@ -468,3 +714,272 @@ describe('runPodDeintegrate', () => {
     );
   });
 });
+
+describe('configureAppForSwift', () => {
+  let mockFs;
+  let mockPath;
+  let mockConsoleLog;
+
+  beforeEach(() => {
+    // Setup mocks
+    mockFs = require('fs');
+    mockPath = require('path');
+    mockConsoleLog = console.log;
+
+    // Clear and reset all mocks completely
+    jest.clearAllMocks();
+    jest.resetAllMocks();
+
+    // Set up fresh mock implementations
+    mockFs.existsSync = jest.fn();
+    mockFs.mkdirSync = jest.fn();
+    mockFs.unlinkSync = jest.fn();
+    mockFs.linkSync = jest.fn();
+    mockFs.symlinkSync = jest.fn();
+    mockFs.writeFileSync = jest.fn();
+
+    // Mock path.join to return realistic paths
+    mockPath.join.mockImplementation((...args) => args.join('/'));
+
+    // Mock path.relative to return realistic relative paths
+    mockPath.relative.mockImplementation((from, to) => {
+      // Simple implementation for tests
+      return to.replace(from + '/', '');
+    });
+  });
+
+  it('should configure app for Swift integration successfully', async () => {
+    // Setup
+    const reactNativePath = '/path/to/react-native';
+
+    // Mock file system calls
+    mockFs.existsSync
+      .mockReturnValueOnce(true) // reactIncludesReactPath exists
+      .mockReturnValueOnce(false) // destUmbrellaPath doesn't exist
+      .mockReturnValueOnce(true); // sourceUmbrellaPath exists
+
+    mockFs.mkdirSync.mockImplementation(() => {});
+    mockFs.symlinkSync.mockImplementation(() => {});
+    mockFs.writeFileSync.mockImplementation(() => {});
+
+    // Execute
+    await configureAppForSwift(reactNativePath);
+
+    // Assert file system calls
+    expect(mockFs.existsSync).toHaveBeenCalledWith(
+      '/path/to/react-native/React/includes/React',
+    );
+    expect(mockFs.existsSync).toHaveBeenCalledWith(
+      '/path/to/react-native/React/includes/React/React-umbrella.h',
+    );
+    expect(mockFs.existsSync).toHaveBeenCalledWith(
+      '/path/to/react-native/scripts/ios-prebuild/React-umbrella.h',
+    );
+
+    expect(mockFs.symlinkSync).toHaveBeenCalledWith(
+      '/path/to/react-native/scripts/ios-prebuild/React-umbrella.h',
+      '/path/to/react-native/React/includes/React/React-umbrella.h',
+    );
+
+    expect(mockFs.linkSync).not.toHaveBeenCalled();
+
+    // Verify module.modulemap content
+    const expectedModuleMapContent = `framework module React {
+  umbrella header "/path/to/react-native/React/includes/React/React-umbrella.h"
+  export *
+  module * { export * }
+}
+`;
+    expect(mockFs.writeFileSync).toHaveBeenCalledWith(
+      '/path/to/react-native/React/includes/module.modulemap',
+      expectedModuleMapContent,
+      'utf8',
+    );
+
+    // Verify console output
+    expect(mockConsoleLog).toHaveBeenCalledWith(
+      'Configuring app for Swift integration...',
+    );
+    expect(mockConsoleLog).toHaveBeenCalledWith(
+      '✓ Created hardlink: React-umbrella.h -> scripts/ios-prebuild/React-umbrella.h',
+    );
+    expect(mockConsoleLog).toHaveBeenCalledWith(
+      '✓ Generated module.modulemap file',
+    );
+    expect(mockConsoleLog).toHaveBeenCalledWith(
+      '✓ App configured for Swift integration',
+    );
+  });
+
+  it('should remove existing hardlink before creating new one', async () => {
+    // Setup
+    const reactNativePath = '/path/to/react-native';
+
+    mockFs.existsSync
+      .mockReturnValueOnce(true) // reactIncludesReactPath exists
+      .mockReturnValueOnce(true) // destUmbrellaPath exists (should be removed)
+      .mockReturnValueOnce(true); // sourceUmbrellaPath exists
+
+    mockFs.mkdirSync.mockImplementation(() => {});
+    mockFs.unlinkSync.mockImplementation(() => {});
+    mockFs.linkSync.mockImplementation(() => {});
+    mockFs.writeFileSync.mockImplementation(() => {});
+
+    // Execute
+    await configureAppForSwift(reactNativePath);
+
+    // Assert
+    expect(mockFs.unlinkSync).toHaveBeenCalledWith(
+      '/path/to/react-native/React/includes/React/React-umbrella.h',
+    );
+  });
+
+  it('should handle different React Native paths', async () => {
+    // Setup
+    const reactNativePath = '/Users/developer/react-native';
+
+    mockFs.existsSync
+      .mockReturnValueOnce(true)
+      .mockReturnValueOnce(false)
+      .mockReturnValueOnce(true);
+
+    mockFs.linkSync.mockImplementation(() => {});
+    mockFs.writeFileSync.mockImplementation(() => {});
+
+    // Execute
+    await configureAppForSwift(reactNativePath);
+
+    // Assert
+    expect(mockFs.symlinkSync).toHaveBeenCalledWith(
+      '/Users/developer/react-native/scripts/ios-prebuild/React-umbrella.h',
+      '/Users/developer/react-native/React/includes/React/React-umbrella.h',
+    );
+
+    expect(mockFs.linkSync).not.toHaveBeenCalled();
+  });
+
+  it('should throw error when source umbrella header does not exist', async () => {
+    // Setup
+    const reactNativePath = '/path/to/react-native';
+
+    mockFs.existsSync
+      .mockReturnValueOnce(true) // reactIncludesReactPath exists
+      .mockReturnValueOnce(false) // destUmbrellaPath doesn't exist
+      .mockReturnValueOnce(false); // sourceUmbrellaPath doesn't exist
+
+    // Execute & Assert
+    await expect(configureAppForSwift(reactNativePath)).rejects.toThrow(
+      'Swift configuration failed: Source umbrella header not found: /path/to/react-native/scripts/ios-prebuild/React-umbrella.h',
+    );
+
+    expect(mockConsoleLog).toHaveBeenCalledWith(
+      'Configuring app for Swift integration...',
+    );
+    expect(mockConsoleLog).not.toHaveBeenCalledWith(
+      '✓ App configured for Swift integration',
+    );
+  });
+
+  it('should throw error when hardlink creation fails', async () => {
+    // Setup
+    const reactNativePath = '/path/to/react-native';
+
+    mockFs.existsSync
+      .mockReturnValueOnce(true)
+      .mockReturnValueOnce(false)
+      .mockReturnValueOnce(true);
+
+    mockFs.symlinkSync.mockImplementation(() => {
+      throw new Error('Permission denied');
+    });
+
+    // Execute & Assert
+    await expect(configureAppForSwift(reactNativePath)).rejects.toThrow(
+      'Swift configuration failed: Permission denied',
+    );
+  });
+
+  it('should throw error when module.modulemap write fails', async () => {
+    // Setup
+    const reactNativePath = '/path/to/react-native';
+
+    mockFs.existsSync
+      .mockReturnValueOnce(true)
+      .mockReturnValueOnce(false)
+      .mockReturnValueOnce(true);
+
+    mockFs.symlinkSync.mockImplementation(() => {});
+    mockFs.writeFileSync.mockImplementation(() => {
+      throw new Error('Disk full');
+    });
+
+    // Execute & Assert
+    await expect(configureAppForSwift(reactNativePath)).rejects.toThrow(
+      'Swift configuration failed: Disk full',
+    );
+  });
+
+  it('should throw error when directory creation fails', async () => {
+    // Setup
+    const reactNativePath = '/path/to/react-native';
+
+    mockFs.existsSync.mockReturnValueOnce(false); // reactIncludesReactPath doesn't exist
+
+    mockFs.mkdirSync.mockImplementation(() => {
+      throw new Error('Permission denied');
+    });
+
+    // Execute & Assert
+    await expect(configureAppForSwift(reactNativePath)).rejects.toThrow(
+      'Swift configuration failed: Permission denied',
+    );
+  });
+
+  it('should handle file unlink errors gracefully', async () => {
+    // Setup
+    const reactNativePath = '/path/to/react-native';
+
+    mockFs.existsSync
+      .mockReturnValueOnce(true)
+      .mockReturnValueOnce(true) // destUmbrellaPath exists
+      .mockReturnValueOnce(true);
+
+    mockFs.unlinkSync.mockImplementation(() => {
+      throw new Error('File in use');
+    });
+
+    // Execute & Assert
+    await expect(configureAppForSwift(reactNativePath)).rejects.toThrow(
+      'Swift configuration failed: File in use',
+    );
+  });
+
+  it('should generate correct module.modulemap content with absolute path', async () => {
+    // Setup
+    const reactNativePath = '/custom/path/to/react-native';
+
+    mockFs.existsSync
+      .mockReturnValueOnce(true)
+      .mockReturnValueOnce(false)
+      .mockReturnValueOnce(true);
+
+    mockFs.linkSync.mockImplementation(() => {});
+    mockFs.writeFileSync.mockImplementation(() => {});
+
+    // Execute
+    await configureAppForSwift(reactNativePath);
+
+    // Assert module.modulemap content with correct absolute path
+    const expectedModuleMapContent = `framework module React {
+  umbrella header "/custom/path/to/react-native/React/includes/React/React-umbrella.h"
+  export *
+  module * { export * }
+}
+`;
+    expect(mockFs.writeFileSync).toHaveBeenCalledWith(
+      '/custom/path/to/react-native/React/includes/module.modulemap',
+      expectedModuleMapContent,
+      'utf8',
+    );
+  });
+});
diff --git a/packages/react-native/scripts/swiftpm/prepare-app-utils.js b/packages/react-native/scripts/swiftpm/prepare-app-utils.js
index 3a15fda0c0d9..902094a145bd 100644
--- a/packages/react-native/scripts/swiftpm/prepare-app-utils.js
+++ b/packages/react-native/scripts/swiftpm/prepare-app-utils.js
@@ -9,6 +9,7 @@
  */
 
 const {execSync} = require('child_process');
+const fs = require('fs');
 const path = require('path');
 
 /**
@@ -85,8 +86,130 @@ async function runIosPrebuild(
     throw new Error(`iOS prebuild failed: ${error.message}`);
   }
 }
+
+/**
+ * Configure app for Swift integration
+ */
+async function configureAppForSwift(
+  reactNativePath /*: string */,
+) /*: Promise<void> */ {
+  try {
+    console.log('Configuring app for Swift integration...');
+
+    // 1. Create hardlink from React-umbrella.h to React-umbrella.h
+    const sourceUmbrellaPath = path.join(
+      reactNativePath,
+      'scripts',
+      'ios-prebuild',
+      'React-umbrella.h',
+    );
+    const reactIncludesReactPath = path.join(
+      reactNativePath,
+      'React',
+      'includes',
+      'React',
+    );
+    const destUmbrellaPath = path.join(
+      reactIncludesReactPath,
+      'React-umbrella.h',
+    );
+
+    // Ensure the React/includes/React directory exists
+    if (!fs.existsSync(reactIncludesReactPath)) {
+      fs.mkdirSync(reactIncludesReactPath, {recursive: true});
+    }
+
+    // Remove existing hardlink if it exists
+    if (fs.existsSync(destUmbrellaPath)) {
+      fs.unlinkSync(destUmbrellaPath);
+    }
+
+    // Create hardlink for umbrella header
+    if (fs.existsSync(sourceUmbrellaPath)) {
+      fs.symlinkSync(sourceUmbrellaPath, destUmbrellaPath);
+      console.log(
+        `✓ Created hardlink: React-umbrella.h -> ${path.relative(
+          reactNativePath,
+          sourceUmbrellaPath,
+        )}`,
+      );
+    } else {
+      throw new Error(
+        `Source umbrella header not found: ${sourceUmbrellaPath}`,
+      );
+    }
+
+    // 2. Generate module.modulemap file
+    const reactIncludesPath = path.join(reactNativePath, 'React', 'includes');
+    const moduleMapPath = path.join(reactIncludesPath, 'module.modulemap');
+    const absoluteUmbrellaPath = path.join(
+      reactNativePath,
+      'React',
+      'includes',
+      'React',
+      'React-umbrella.h',
+    );
+    const moduleMapContent = `framework module React {
+  umbrella header "${absoluteUmbrellaPath}"
+  export *
+  module * { export * }
+}
+`;
+
+    fs.writeFileSync(moduleMapPath, moduleMapContent, 'utf8');
+    console.log('✓ Generated module.modulemap file');
+
+    console.log('✓ App configured for Swift integration');
+  } catch (error) {
+    throw new Error(`Swift configuration failed: ${error.message}`);
+  }
+}
+
+/**
+ * Set BUILD_FROM_SOURCE to true in Package.swift
+ */
+async function setBuildFromSource(
+  reactNativePath /*: string */,
+) /*: Promise<void> */ {
+  const packageSwiftPath = path.join(reactNativePath, 'Package.swift');
+
+  if (!fs.existsSync(packageSwiftPath)) {
+    throw new Error(`Package.swift not found at: ${packageSwiftPath}`);
+  }
+
+  try {
+    console.log(`Updating BUILD_FROM_SOURCE in: ${packageSwiftPath}`);
+
+    const content = fs.readFileSync(packageSwiftPath, 'utf8');
+
+    // Check if BUILD_FROM_SOURCE = false exists and replace it with true
+    if (content.includes('let BUILD_FROM_SOURCE = false')) {
+      const updatedContent = content.replace(
+        /let BUILD_FROM_SOURCE = false/g,
+        'let BUILD_FROM_SOURCE = true',
+      );
+      fs.writeFileSync(packageSwiftPath, updatedContent, 'utf8');
+      console.log('✓ BUILD_FROM_SOURCE set to true in Package.swift');
+    } else if (content.includes('let BUILD_FROM_SOURCE = true')) {
+      console.log(
+        '✓ BUILD_FROM_SOURCE is already set to true in Package.swift',
+      );
+    } else {
+      console.warn(
+        '⚠️  BUILD_FROM_SOURCE declaration not found in Package.swift',
+      );
+    }
+  } catch (error) {
+    throw new Error(
+      `Failed to update BUILD_FROM_SOURCE in Package.swift: ${error.message}`,
+    );
+  }
+}
+
 module.exports = {
   findXcodeProjectDirectory,
   runPodDeintegrate,
   runIosPrebuild,
+  configureAppForSwift,
+  setBuildFromSource,
 };