diff --git a/packages/hlsjs/README.md b/packages/hlsjs/README.md
index 6197dc17..edc2883c 100644
--- a/packages/hlsjs/README.md
+++ b/packages/hlsjs/README.md
@@ -11,3 +11,9 @@ Using https://www.svgrepo.com/collection/solar-broken-line-icons for icons.
 - Selecting audio and quality during interstitials works for the main asset, but subtitles not.
 
 - Seeking to `this.getInterstitialsManager_().integrated.duration` does not work properly.
+
+- InterstitialEvent should contain custom tags (like X-MIX-TYPES).
+
+- Need to talk about ABR & interstitials, do they share the same instance? Same bandwidth estimation? That might give troubles as for all we know eg; interstitials might be on a different CDN.
+
+- Custom HLS tags? Is this needed?
diff --git a/packages/hlsjs/lib/main.ts b/packages/hlsjs/lib/main.ts
index db1baa7b..d1e3b1e1 100644
--- a/packages/hlsjs/lib/main.ts
+++ b/packages/hlsjs/lib/main.ts
@@ -2,7 +2,7 @@ import Hls from "hls.js";
 import update from "immutability-helper";
 import EventEmitter from "eventemitter3";
 import type { Spec } from "immutability-helper";
-import type { Level, MediaPlaylist } from "hls.js";
+import type { InterstitialScheduleItem, Level, MediaPlaylist } from "hls.js";
 
 export { Root as HlsUi } from "./ui";
 
@@ -123,10 +123,20 @@ export class HlsFacade extends EventEmitter<HlsFacadeEvent> {
     });
 
     hls.on(Hls.Events.INTERSTITIALS_UPDATED, (_, data) => {
+      const isAd = (item: InterstitialScheduleItem) => {
+        const types = item.event?.dateRange.attr.enumeratedStringList(
+          "X-MIX-TYPES",
+          {
+            ad: false,
+          },
+        );
+        return !!types?.ad;
+      };
+
       this.setState_({
         cuePoints: {
           $set: data.schedule.reduce<number[]>((acc, item) => {
-            if (!acc.includes(item.start)) {
+            if (isAd(item) && !acc.includes(item.start)) {
               acc.push(item.start);
             }
             return acc;
diff --git a/packages/hlsjs/src/main.tsx b/packages/hlsjs/src/main.tsx
index 23b85112..3ac92889 100644
--- a/packages/hlsjs/src/main.tsx
+++ b/packages/hlsjs/src/main.tsx
@@ -15,8 +15,11 @@ Object.assign(window, { facade });
 
 hls.loadSource(
   // "https://streamer.ams3.cdn.digitaloceanspaces.com/package/846ed9ef-b11f-43a4-9d31-0cecc1b7468c/hls/master.m3u8",
-  "https://playertest.longtailvideo.com/adaptive/elephants_dream_v4/redundant.m3u8",
+  // "https://playertest.longtailvideo.com/adaptive/elephants_dream_v4/redundant.m3u8",
   // "http://127.0.0.1:52002/session/260c015b-966f-4cc4-8373-ab859379a27d/master.m3u8",
+  // "http://127.0.0.1:52002/session/d8f508ab-8c93-41fa-9afe-63a784477d8b/master.m3u8",
+  "https://test-streams.mux.dev/x36xhzz/x36xhzz.m3u8",
+  // "http://127.0.0.1:52002/session/a7b1551f-5baf-4859-b783-b3c674a77690/master.m3u8",
 );
 
 const root = ReactDOM.createRoot(document.getElementById("root")!);
diff --git a/packages/stitcher/extern/hls-parser/stringify.ts b/packages/stitcher/extern/hls-parser/stringify.ts
index c32df2b6..3a03f161 100644
--- a/packages/stitcher/extern/hls-parser/stringify.ts
+++ b/packages/stitcher/extern/hls-parser/stringify.ts
@@ -370,6 +370,12 @@ function buildMediaPlaylist(
       `X-RESTRICT="${interstitial.restrict}"`,
     );
 
+    if (interstitial.custom) {
+      Object.entries(interstitial.custom).forEach(([key, value]) => {
+        params.push(`X-${key}="${value}"`);
+      });
+    }
+
     lines.push(`#EXT-X-DATERANGE:${params.join(",")}`);
   }
 }
diff --git a/packages/stitcher/extern/hls-parser/types.ts b/packages/stitcher/extern/hls-parser/types.ts
index ed11d892..8bc93da4 100644
--- a/packages/stitcher/extern/hls-parser/types.ts
+++ b/packages/stitcher/extern/hls-parser/types.ts
@@ -60,6 +60,7 @@ class Interstitial {
   startDate: Date;
   resumeOffset?: number;
   restrict?: string;
+  custom?: Record<string, string>;
 
   constructor({
     id,
@@ -69,6 +70,7 @@ class Interstitial {
     startDate,
     resumeOffset = 0,
     restrict = "SKIP,JUMP",
+    custom,
   }: any) {
     this.id = id;
     this.uri = uri;
@@ -77,6 +79,7 @@ class Interstitial {
     this.startDate = startDate;
     this.resumeOffset = resumeOffset;
     this.restrict = restrict;
+    this.custom = custom;
   }
 }
 
diff --git a/packages/stitcher/src/playlist.ts b/packages/stitcher/src/playlist.ts
index 8ec7533e..e2020afd 100644
--- a/packages/stitcher/src/playlist.ts
+++ b/packages/stitcher/src/playlist.ts
@@ -3,7 +3,7 @@ import parseFilepath from "parse-filepath";
 import { env } from "./env.js";
 import { MasterPlaylist, MediaPlaylist } from "../extern/hls-parser/types.js";
 import createError from "@fastify/error";
-import type { Session, Interstitial } from "./types.js";
+import type { Session, Interstitial, InterstitialType } from "./types.js";
 
 const PlaylistUnavailableError = createError<[string]>(
   "PLAYLIST_UNAVAILABLE",
@@ -80,6 +80,7 @@ export async function formatAssetList(session: Session, timeOffset: number) {
       return {
         URI: uri,
         DURATION: await getDuration(uri),
+        "MIX-TYPE": interstitial.type,
       };
     }),
   );
@@ -118,18 +119,40 @@ function addInterstitials(
   media.segments[0].programDateTime = new Date(now);
 
   interstitials
-    .reduce<number[]>((acc, interstitial) => {
-      if (!acc.includes(interstitial.timeOffset)) {
-        acc.push(interstitial.timeOffset);
+    .reduce<
+      {
+        timeOffset: number;
+        types: InterstitialType[];
+      }[]
+    >((acc, interstitial) => {
+      let foundItem = acc.find(
+        (item) => item.timeOffset === interstitial.timeOffset,
+      );
+      if (!foundItem) {
+        foundItem = {
+          timeOffset: interstitial.timeOffset,
+          types: [],
+        };
+        acc.push(foundItem);
+      }
+
+      if (interstitial.type && !foundItem.types.includes(interstitial.type)) {
+        foundItem.types.push(interstitial.type);
       }
+
       return acc;
     }, [])
-    .forEach((timeOffset) => {
+    .forEach((item) => {
+      const custom = {
+        "MIX-TYPES": item.types.join(","),
+      };
+
       media.interstitials.push(
         new hlsParser.types.Interstitial({
-          id: `${timeOffset}`,
-          startDate: new Date(now + timeOffset * 1000),
-          list: `/session/${sessionId}/asset-list.json?timeOffset=${timeOffset}`,
+          id: `${item.timeOffset}`,
+          startDate: new Date(now + item.timeOffset * 1000),
+          list: `/session/${sessionId}/asset-list.json?timeOffset=${item.timeOffset}`,
+          custom,
         }),
       );
     });
diff --git a/packages/stitcher/src/session.ts b/packages/stitcher/src/session.ts
index 907eaf6f..402e4973 100644
--- a/packages/stitcher/src/session.ts
+++ b/packages/stitcher/src/session.ts
@@ -47,6 +47,7 @@ export async function createSession(data: {
     interstitials.push({
       timeOffset: 0,
       assetId: data.bumperAssetId,
+      type: "bumper",
     });
   }
 
diff --git a/packages/stitcher/src/types.ts b/packages/stitcher/src/types.ts
index f3dc7c5f..1541c63b 100644
--- a/packages/stitcher/src/types.ts
+++ b/packages/stitcher/src/types.ts
@@ -5,7 +5,10 @@ export type Session = {
   maxResolution: number;
 };
 
+export type InterstitialType = "ad" | "bumper";
+
 export type Interstitial = {
   timeOffset: number;
   assetId: string;
+  type?: InterstitialType;
 };
diff --git a/packages/stitcher/src/vast.ts b/packages/stitcher/src/vast.ts
index deeca326..32a37762 100644
--- a/packages/stitcher/src/vast.ts
+++ b/packages/stitcher/src/vast.ts
@@ -22,6 +22,7 @@ export async function extractInterstitialFromVmapAdbreak(adBreak: VmapAdBreak) {
       interstitials.push({
         timeOffset: adBreak.timeOffset,
         assetId: adMedia.assetId,
+        type: "ad",
       });
     } else {
       scheduleForPackage(adMedia);