diff --git a/lib/assets/assetManager.ts b/lib/assets/assetManager.ts
index 3d5525b..18e1387 100644
--- a/lib/assets/assetManager.ts
+++ b/lib/assets/assetManager.ts
@@ -16,6 +16,7 @@ export type AssetRef = {
 export type AssetManagerOptions = {
   maxBytes: number
   allowedExts: string[] // e.g., ['png','jpg','jpeg','webp','svg']
+  pathStrategy?: 'flat' | 'grouped'
 }
 
 function extOf(name: string): string {
@@ -36,6 +37,7 @@ function hash8(bytes: Uint8Array): string {
 export class AssetManager {
   private readonly maxBytes: number
   private readonly allowed: Set<string>
+  private readonly pathStrategy: 'flat' | 'grouped'
   private byHash = new Map<string, AssetRef>()
   private byOriginal = new Map<string, string>() // originalName -> path
   private referenced = new Set<string>() // originalName referenced via rewrite
@@ -43,6 +45,7 @@ export class AssetManager {
   constructor(opts: AssetManagerOptions) {
     this.maxBytes = opts.maxBytes
     this.allowed = new Set(opts.allowedExts.map((e) => e.toLowerCase()))
+    this.pathStrategy = opts.pathStrategy ?? 'flat'
   }
 
   async add(file: AssetInput): Promise<AssetRef> {
@@ -61,7 +64,7 @@ export class AssetManager {
       return existing
     }
 
-    const path = `assets/${h}.${ext}`
+    const path = this.makePath(h, ext, file.type)
     const ref: AssetRef = {
       originalName: file.name,
       mimeType: file.type,
@@ -101,4 +104,14 @@ export class AssetManager {
   referencedList(): string[] {
     return Array.from(this.referenced)
   }
+
+  private makePath(hash8: string, ext: string, mime: string): string {
+    if (this.pathStrategy === 'grouped') {
+      let group = 'other'
+      if (mime.startsWith('image/')) group = 'images'
+      else if (mime.startsWith('font/')) group = 'fonts'
+      return `assets/${group}/${hash8}.${ext}`
+    }
+    return `assets/${hash8}.${ext}`
+  }
 }
diff --git a/lib/exporter/assets.index.test.ts b/lib/exporter/assets.index.test.ts
new file mode 100644
index 0000000..fc278f9
--- /dev/null
+++ b/lib/exporter/assets.index.test.ts
@@ -0,0 +1,22 @@
+import { describe, it, expect } from 'vitest'
+import { AssetManager } from '@/lib/assets/assetManager'
+import { buildAssetsIndex } from '@/lib/exporter/assets.index'
+
+function u8(n: number): Uint8Array { const a = new Uint8Array(n); for (let i=0;i<n;i++) a[i]=i&0xff; return a }
+
+describe('Assets index builder', () => {
+  it('groups assets by mime into images/fonts/other and lists zipPath', async () => {
+    const am = new AssetManager({ maxBytes: 1024*1024, allowedExts: ['png','woff2','txt'] })
+    await am.add({ name: 'a.png', type: 'image/png', bytes: u8(4) })
+    await am.add({ name: 'b.woff2', type: 'font/woff2', bytes: u8(6) })
+    await am.add({ name: 'c.txt', type: 'text/plain', bytes: u8(2) })
+    const bytes = buildAssetsIndex(am)
+    const obj = JSON.parse(new TextDecoder().decode(bytes)) as { images: string[]; fonts: string[]; other: string[] }
+    expect(obj.images.length).toBe(1)
+    expect(obj.fonts.length).toBe(1)
+    expect(obj.other.length).toBe(1)
+    expect(obj.images[0]).toMatch(/^assets\/[0-9a-f]{8}\.png$/)
+    expect(obj.fonts[0]).toMatch(/^assets\/[0-9a-f]{8}\.woff2$/)
+    expect(obj.other[0]).toMatch(/^assets\/[0-9a-f]{8}\.txt$/)
+  })
+})
diff --git a/lib/exporter/assets.index.ts b/lib/exporter/assets.index.ts
new file mode 100644
index 0000000..fb82246
--- /dev/null
+++ b/lib/exporter/assets.index.ts
@@ -0,0 +1,21 @@
+import type { AssetManager } from '@/lib/assets/assetManager'
+
+export type AssetsIndex = {
+  images: string[]
+  fonts: string[]
+  other: string[]
+}
+
+export function buildAssetsIndex(am: AssetManager): Uint8Array {
+  const images: string[] = []
+  const fonts: string[] = []
+  const other: string[] = []
+  for (const ref of am.list()) {
+    if (ref.mimeType.startsWith('image/')) images.push(ref.path)
+    else if (ref.mimeType.startsWith('font/')) fonts.push(ref.path)
+    else other.push(ref.path)
+  }
+  const obj: AssetsIndex = { images, fonts, other }
+  const json = JSON.stringify(obj, null, 2)
+  return new TextEncoder().encode(json)
+}