diff --git a/packages/theme/src/cli/services/package.test.ts b/packages/theme/src/cli/services/package.test.ts
index 24300fbc4b6..edbf5bae0d3 100644
--- a/packages/theme/src/cli/services/package.test.ts
+++ b/packages/theme/src/cli/services/package.test.ts
@@ -16,6 +16,7 @@ describe('packageTheme', () => {
       await mkdir(inputDirectory)
       const themeRelativePaths = [
         'AGENTS.md',
+        'DESIGN.md',
         'assets/base.css',
         'layout/theme.liquid',
         'config/settings_schema.json',
diff --git a/packages/theme/src/cli/services/package.ts b/packages/theme/src/cli/services/package.ts
index 239865e718d..bfe10e0b60a 100644
--- a/packages/theme/src/cli/services/package.ts
+++ b/packages/theme/src/cli/services/package.ts
@@ -7,6 +7,7 @@ import {parseJSON} from '@shopify/theme-check-node'
 
 const themeFilesPattern = [
   'AGENTS.md',
+  'DESIGN.md',
   'assets/**',
   'blocks/**',
   'config/**',
diff --git a/packages/theme/src/cli/utilities/fixtures/theme/DESIGN.md b/packages/theme/src/cli/utilities/fixtures/theme/DESIGN.md
new file mode 100644
index 00000000000..be9d93f24b2
--- /dev/null
+++ b/packages/theme/src/cli/utilities/fixtures/theme/DESIGN.md
@@ -0,0 +1,3 @@
+# Theme design
+
+Use the existing visual language.
diff --git a/packages/theme/src/cli/utilities/theme-fs.test.ts b/packages/theme/src/cli/utilities/theme-fs.test.ts
index f2ded99a372..d9b4a07b87a 100644
--- a/packages/theme/src/cli/utilities/theme-fs.test.ts
+++ b/packages/theme/src/cli/utilities/theme-fs.test.ts
@@ -66,13 +66,14 @@ describe('theme-fs', () => {
 
         // Then
         expect(themeFileSystem.root).toBe(root)
-        expect(themeFileSystem.files.size).toBe(12)
+        expect(themeFileSystem.files.size).toBe(13)
         expect(themeFileSystem.unsyncedFileKeys).toEqual(new Set())
         expect(themeFileSystem.uploadErrors).toEqual(new Map())
 
         // Check that all expected files are present with correct checksums
         const expectedFiles = [
           {checksum: '6e3520cc5a5c4cdb1267f36406c732a1', key: 'AGENTS.md'},
+          {checksum: 'f5e9ce97aef578fc4e2e369a3c271234', key: 'DESIGN.md'},
           {checksum: 'b7fbe0ecff2a6c1d6e697a13096e2b17', key: 'assets/base.css'},
           {checksum: '7adcd48a3cc215a81fabd9dafb919507', key: 'assets/sparkle.gif'},
           {checksum: '22e69af13b7953914563c60035a831bc', key: 'config/settings_data.json'},
@@ -520,6 +521,7 @@ describe('theme-fs', () => {
         {key: 'templates/404.liquid', checksum: '13'},
         {key: 'blocks/block.liquid', checksum: '14'},
         {key: 'AGENTS.md', checksum: '17'},
+        {key: 'DESIGN.md', checksum: '18'},
       ]
       // When
       const {
@@ -534,7 +536,7 @@ describe('theme-fs', () => {
         contextualizedJsonFiles,
         blockLiquidFiles,
         layoutFiles,
-        agentInstructionFiles,
+        documentationFiles,
       } = partitionThemeFiles(files)
 
       // Then
@@ -560,7 +562,10 @@ describe('theme-fs', () => {
         {key: 'layout/theme.liquid', checksum: '5'},
         {key: 'layout/custom.liquid', checksum: '15'},
       ])
-      expect(agentInstructionFiles).toEqual([{key: 'AGENTS.md', checksum: '17'}])
+      expect(documentationFiles).toEqual([
+        {key: 'AGENTS.md', checksum: '17'},
+        {key: 'DESIGN.md', checksum: '18'},
+      ])
     })
 
     test('should handle empty file array', () => {
@@ -577,7 +582,7 @@ describe('theme-fs', () => {
         configDataFile,
         configStylesheetFiles,
         staticAssetFiles,
-        agentInstructionFiles,
+        documentationFiles,
       } = partitionThemeFiles(files)
 
       // Then
@@ -589,7 +594,7 @@ describe('theme-fs', () => {
       expect(configDataFile).toEqual([])
       expect(configStylesheetFiles).toEqual([])
       expect(staticAssetFiles).toEqual([])
-      expect(agentInstructionFiles).toEqual([])
+      expect(documentationFiles).toEqual([])
     })
   })
 
@@ -603,6 +608,7 @@ describe('theme-fs', () => {
       expect(isTextFile('sections/template.liquid')).toBeTruthy()
       expect(isTextFile('templates/cart.json')).toBeTruthy()
       expect(isTextFile('AGENTS.md')).toBeTruthy()
+      expect(isTextFile('DESIGN.md')).toBeTruthy()
     })
 
     test(`returns false when it's not a text file`, async () => {
diff --git a/packages/theme/src/cli/utilities/theme-fs.ts b/packages/theme/src/cli/utilities/theme-fs.ts
index 4cc4e3c3f7e..436d2878903 100644
--- a/packages/theme/src/cli/utilities/theme-fs.ts
+++ b/packages/theme/src/cli/utilities/theme-fs.ts
@@ -30,6 +30,7 @@ const FILE_EVENT_DEBOUNCE_TIME_IN_MS = 250
 
 const THEME_DIRECTORY_PATTERNS = [
   'AGENTS.md',
+  'DESIGN.md',
   'assets/**/*.*',
   'config/**/*.json',
   'config/styles.css',
@@ -43,7 +44,7 @@ const THEME_DIRECTORY_PATTERNS = [
 ]
 
 const THEME_PARTITION_REGEX = {
-  agentInstructionsRegex: /^AGENTS\.md$/,
+  documentationFilesRegex: /^(AGENTS|DESIGN)\.md$/,
   layoutLiquidRegex: /^layout\/.+\.liquid$/,
   sectionLiquidRegex: /^sections\/.+\.liquid$/,
   blockLiquidRegex: /^blocks\/.+\.liquid$/,
@@ -476,12 +477,12 @@ export function partitionThemeFiles<T extends {key: string}>(files: T[]) {
   const staticAssetFiles: T[] = []
   const blockLiquidFiles: T[] = []
   const layoutFiles: T[] = []
-  const agentInstructionFiles: T[] = []
+  const documentationFiles: T[] = []
 
   files.forEach((file) => {
     const fileKey = file.key
-    if (THEME_PARTITION_REGEX.agentInstructionsRegex.test(fileKey)) {
-      agentInstructionFiles.push(file)
+    if (THEME_PARTITION_REGEX.documentationFilesRegex.test(fileKey)) {
+      documentationFiles.push(file)
     } else if (fileKey.endsWith('.liquid')) {
       if (THEME_PARTITION_REGEX.sectionLiquidRegex.test(fileKey)) {
         sectionLiquidFiles.push(file)
@@ -526,7 +527,7 @@ export function partitionThemeFiles<T extends {key: string}>(files: T[]) {
     staticAssetFiles,
     blockLiquidFiles,
     layoutFiles,
-    agentInstructionFiles,
+    documentationFiles,
   }
 }
 
diff --git a/packages/theme/src/cli/utilities/theme-uploader.test.ts b/packages/theme/src/cli/utilities/theme-uploader.test.ts
index 396c6b8b8f3..a70dcbe961f 100644
--- a/packages/theme/src/cli/utilities/theme-uploader.test.ts
+++ b/packages/theme/src/cli/utilities/theme-uploader.test.ts
@@ -257,6 +257,7 @@ describe('theme-uploader', () => {
       {key: 'config/settings_data.json', checksum: '6'},
       {key: 'config/styles.css', checksum: '9'},
       {key: 'AGENTS.md', checksum: '10'},
+      {key: 'DESIGN.md', checksum: '11'},
       {key: 'assets/image.png', checksum: '7'},
       {key: 'layout/custom.liquid', checksum: '8'},
     ]
@@ -286,6 +287,7 @@ describe('theme-uploader', () => {
         'config/settings_data.json',
         'config/styles.css',
         'AGENTS.md',
+        'DESIGN.md',
         'assets/image.png',
       ],
       adminSession,
@@ -311,6 +313,7 @@ describe('theme-uploader', () => {
         ['layout/theme.liquid', {key: 'layout/theme.liquid', checksum: '10'}],
         ['config/styles.css', {key: 'config/styles.css', checksum: '11', value: ':root { --color-primary: #000; }'}],
         ['AGENTS.md', {key: 'AGENTS.md', checksum: '12', value: '# Theme instructions'}],
+        ['DESIGN.md', {key: 'DESIGN.md', checksum: '13', value: '# Theme design'}],
       ]),
     )
 
@@ -359,6 +362,10 @@ describe('theme-uploader', () => {
           key: 'AGENTS.md',
           value: '# Theme instructions',
         },
+        {
+          key: 'DESIGN.md',
+          value: '# Theme design',
+        },
       ],
       adminSession,
     )
diff --git a/packages/theme/src/cli/utilities/theme-uploader.ts b/packages/theme/src/cli/utilities/theme-uploader.ts
index 6a4254cf248..49522d71faf 100644
--- a/packages/theme/src/cli/utilities/theme-uploader.ts
+++ b/packages/theme/src/cli/utilities/theme-uploader.ts
@@ -215,7 +215,7 @@ function orderFilesToBeDeleted(files: Checksum[]): Checksum[] {
     ...fileSets.otherLiquidFiles,
     ...fileSets.configDataFile,
     ...fileSets.configStylesheetFiles,
-    ...fileSets.agentInstructionFiles,
+    ...fileSets.documentationFiles,
     ...fileSets.configSchemaFile,
     ...fileSets.staticAssetFiles,
   ]
@@ -337,7 +337,7 @@ function selectUploadableFiles(themeFileSystem: ThemeFileSystem, remoteChecksums
  * - The other JSON files (for example, locales)
  * - The static assets
  * - Config stylesheets
- * - Agent instructions
+ * - Root documentation files
  *
  */
 function orderFilesToBeUploaded(files: ChecksumWithSize[]): {
@@ -353,7 +353,7 @@ function orderFilesToBeUploaded(files: ChecksumWithSize[]): {
       fileSets.otherJsonFiles,
       fileSets.staticAssetFiles,
       fileSets.configStylesheetFiles,
-      fileSets.agentInstructionFiles,
+      fileSets.documentationFiles,
     ],
     // Follow order of dependencies:
     dependentFiles: [