diff --git a/dbTools/post.js b/dbTools/post.js
index aec2df6..906ef02 100644
--- a/dbTools/post.js
+++ b/dbTools/post.js
@@ -12,6 +12,7 @@ postDB = (DB)=>{
     }
 
     DB.removePost = (postid) => {
+        if(!DB.ObjectID.isValid(postid)) return false;
         const _id = DB.ObjectID(postid);
         return DB.postCols.deleteOne({_id}).catch((err)=>{
             console.log(err);
@@ -20,6 +21,7 @@ postDB = (DB)=>{
     }
 
     DB.updatePost = (postid, newContent, oldContent) => {
+        if(!DB.ObjectID.isValid(postid)) return false;
         const id = DB.ObjectID(postid);
         let update = {
             $set:{
@@ -37,6 +39,7 @@ postDB = (DB)=>{
     }
 
     DB.newReaction = (postid, profileid, reaction) => {
+        if(!DB.ObjectID.isValid(postid)) return false;
         const id = DB.ObjectID(postid);
         let update = {
             $set:{
@@ -51,6 +54,7 @@ postDB = (DB)=>{
     }
 
     DB.removeReaction = (postid, profileid) => {
+        if(!DB.ObjectID.isValid(postid)) return false;
         const id = DB.ObjectID(postid);
         let update = {
             $unset:{
@@ -67,6 +71,7 @@ postDB = (DB)=>{
     }
 
     DB.bookmarkPost = async (postid, profileId)=>{
+        if(!DB.ObjectID.isValid(postid)) return false;
         const _id = DB.ObjectID(postid);
         let update = {
             $addToSet:{
@@ -80,6 +85,7 @@ postDB = (DB)=>{
     }
 
     DB.unbookmarkPost = async (postid, profileId)=>{
+        if(!DB.ObjectID.isValid(postid)) return false;
         const _id = DB.ObjectID(postid);
         let update = {
             $pull:{
@@ -93,6 +99,7 @@ postDB = (DB)=>{
     }
 
     DB.newComment = (postid, comment) => {
+        if(!DB.ObjectID.isValid(postid)) return false;
         const id = DB.ObjectID(postid);
         return DB.postCols.updateOne({_id: id}, {
             $push: {
@@ -108,6 +115,7 @@ postDB = (DB)=>{
     }
 
     DB.newCommentReaction = (postid, commentDate, profileid, reaction) => {
+        if(!DB.ObjectID.isValid(postid)) return false;
         const id = DB.ObjectID(postid);
         let update = {
             $set:{
@@ -126,6 +134,7 @@ postDB = (DB)=>{
     }
 
     DB.removeCommentReaction = (postid, commentDate, profileid) => {
+        if(!DB.ObjectID.isValid(postid)) return false;
         const id = DB.ObjectID(postid);
         let update = {
             $unset:{
@@ -193,6 +202,7 @@ postDB = (DB)=>{
     }
 
     DB.getFeed = async (profileId) => {
+        if(!DB.ObjectID.isValid(profileId)) return [];
         const profile = await DB.getProfile(profileId);
         if(!profile) return [];
         let ids = profile.following.map((id)=>DB.ObjectID(id));
@@ -226,36 +236,48 @@ postDB = (DB)=>{
         });
     }
 
-    DB.getPostsOfUser = (userId) => {
+    DB.getPostsOfUser = (userId, limit = 20) => {
+        if(!DB.ObjectID.isValid(userId)) return [];
         let userid = DB.ObjectID(userId);
         console.log("getPostsOfUser")
-        return DB.postCols.find({userid}).sort({_id: -1}).limit(20).toArray().catch((err)=>{
+        return DB.postCols.find({userid}).sort({_id: -1}).limit(limit).toArray().catch((err)=>{
             console.log(err);
             return false;
         });
     }
 
-    DB.getImagesOfUser = (userId) => {
-        let userid = DB.ObjectID(userId);
+    DB.getMediaTagPostOfUser = (profileId, mediaTag = "@image:", limit = 20) => {
+        if(!DB.ObjectID.isValid(profileId)) return [];
+        let profileid = DB.ObjectID(profileId);
         let query = {
-            userid,
+            profileid,
             content: {
-                $regex: "@image"
+                "$regex": mediaTag
             }
         }
-        return DB.postCols.find(query).sort({_id: -1}).limit(20).toArray().catch((err)=>{
+        return DB.postCols.find(query).sort({_id: -1}).limit(limit).toArray().catch((err)=>{
             console.log(err);
             return false;
         });
     }
 
     DB.getPost = (postId) => {
+        if(!DB.ObjectID.isValid(postId)) return [];
         let _id = DB.ObjectID(postId);
         return DB.postCols.findOne({_id}).catch((err)=>{
             console.log(err);
             return false;
         });
     }
+
+    const postsCache = {};
+    DB.getPostCached = async (postId, refresh = false) => {
+        if(!DB.ObjectID.isValid(postId)) return [];
+        if(!postsCache[postId] || refresh){
+            postsCache[postId] = await DB.getPost(postId);
+        }
+        return postsCache[postId];
+    }
     
 }
 
diff --git a/routes/post.js b/routes/post.js
index 7d54d93..515a076 100644
--- a/routes/post.js
+++ b/routes/post.js
@@ -101,6 +101,15 @@ DB.getDB.then((DB) => {
         return res.json(posts);
     });
 
+    router.get("/usr/:id/images", async (req, res) => {
+        const profileid = req.params.id;
+        const posts = await DB.getMediaTagPostOfUser(profileid);
+        return res.json({
+            status: "ok",
+            posts
+        });
+    });
+
     router.get("/video/:id", async (req, res) => {
         videoId = req.params.id;
         return res.json([]);
@@ -218,6 +227,80 @@ DB.getDB.then((DB) => {
         })
     });
 
+    router.get("/images", async (req, res) => {
+        const profileid = getProfileId(req);
+        const posts = await DB.getMediaTagPostOfUser(profileid);
+        return res.json({
+            status: "ok",
+            posts
+        });
+    });
+
+    router.get("/embedded", async (req, res) => {
+        const profileid = getProfileId(req);
+        const posts = await DB.getMediaTagPostOfUser(profileid, "@iframe:");
+        return res.json({
+            status: "ok",
+            posts
+        });
+    });
+
+    router.get("/media", async (req, res) => {
+        const profileid = getProfileId(req);
+        const posts = await DB.getMediaTagPostOfUser(profileid, "@youtube:|@vimeo:|@hls:");
+        return res.json({
+            status: "ok",
+            posts
+        });
+    });
+
+    router.get("/course/recent", async (req, res) => {
+        const profileid = getProfileId(req);
+        const profile = await DB.getProfileCache(profileid);
+        const mediaPostsId = []
+        const recentMedia = {};
+        const mediaProfileP = []
+        let postPromises = [];
+        // Get watch information from profile data
+        Object.keys(profile.data).forEach(key => {
+            // So far we only use watch info using postid keys
+            if(DB.ObjectID.isValid(key)){
+                mediaPostsId.push(profile.data[key]);
+                postPromises.push(DB.getPostCached(profile.data[key].postId));
+                if(!recentMedia[profile.data[key].profileId]){
+                    recentMedia[profile.data[key].profileId] = [];
+                    mediaProfileP.push(DB.getProfileCache(profile.data[key].profileId));
+                }
+            }
+        });
+        recentMediaArray = mediaPostsId.sort((a,b)=>{
+            return b.ts - a.ts;
+        });
+        const postObjs = await Promise.all(postPromises);
+        const postObjsMap = postObjs.reduce((map, item)=>{
+            map[item._id] = item;
+            return map
+        }, {});
+        recentMediaArray.forEach(record => {
+            const postAndRecord = {
+                watchRecord: record,
+                ... postObjsMap[record.postId]
+            }
+            recentMedia[record.profileId].push(postAndRecord);
+        });
+        // Transform profiles array to dict
+        let mediaProfile = await Promise.all(mediaProfileP);
+        let mediaProfileMap = mediaProfile.reduce((dict, item) => {
+                dict[item._id] = item;
+                return dict;
+            }, {});
+        return res.json({
+            status: "ok",
+            recentMedia,
+            mediaProfileMap,
+        });
+    });
+
     router.get("/:id", async (req, res) => {
         const postId = req.params.id;
         const post = await DB.getPost(postId);