diff --git a/src/activity_pub/actor.rs b/src/activity_pub/actor.rs
index e500128..b699652 100644
--- a/src/activity_pub/actor.rs
+++ b/src/activity_pub/actor.rs
@@ -10,24 +10,19 @@ pub trait Actor: Sized {
 
     fn get_instance(&self, conn: &PgConnection) -> Instance;
 
-    fn compute_outbox(&self, conn: &PgConnection) -> String {
-        self.compute_box(conn, "outbox")
-    }
+    // fn compute_outbox(&self, conn: &PgConnection) -> String {
+    //     self.compute_box(conn, "outbox")
+    // }
 
-    fn compute_inbox(&self, conn: &PgConnection) -> String {
-        self.compute_box(conn, "inbox")
-    }
+    // fn compute_inbox(&self, conn: &PgConnection) -> String {
+    //     self.compute_box(conn, "inbox")
+    // }
 
-    fn compute_box(&self, conn: &PgConnection, box_name: &str) -> String {
-        format!("{id}/{name}", id = self.compute_id(conn), name = box_name)
-    }
+    // fn compute_box(&self, conn: &PgConnection, box_name: &str) -> String {
+    //     format!("{id}/{name}", id = self.compute_id(conn), name = box_name)
+    // }
 
-    fn compute_id(&self, conn: &PgConnection) -> String {
-        ap_url(format!(
-            "{instance}/{prefix}/{user}",
-            instance = self.get_instance(conn).public_domain,
-            prefix = Self::get_box_prefix(),
-            user = self.get_actor_id()
-        ))
-    }
+    // fn compute_id(&self, conn: &PgConnection) -> String {
+    //     String::new()
+    // }
 }
diff --git a/src/models/blogs.rs b/src/models/blogs.rs
index e62fa08..f2fdd9a 100644
--- a/src/models/blogs.rs
+++ b/src/models/blogs.rs
@@ -55,6 +55,8 @@ pub struct NewBlog {
     pub public_key: String
 }
 
+const BLOG_PREFIX: &'static str = "~";
+
 impl Blog {
     insert!(blogs, NewBlog);
     get!(blogs);
@@ -142,21 +144,22 @@ impl Blog {
     }
 
     pub fn update_boxes(&self, conn: &PgConnection) {
+        let instance = self.get_instance(conn);
         if self.outbox_url.len() == 0 {
             diesel::update(self)
-                .set(blogs::outbox_url.eq(self.compute_outbox(conn)))
+                .set(blogs::outbox_url.eq(instance.compute_box(BLOG_PREFIX, self.actor_id.clone(), "outbox")))
                 .get_result::<Blog>(conn).expect("Couldn't update outbox URL");
         }
 
         if self.inbox_url.len() == 0 {
             diesel::update(self)
-                .set(blogs::inbox_url.eq(self.compute_inbox(conn)))
+                .set(blogs::inbox_url.eq(instance.compute_box(BLOG_PREFIX, self.actor_id.clone(), "inbox")))
                 .get_result::<Blog>(conn).expect("Couldn't update inbox URL");
         }
 
         if self.ap_url.len() == 0 {
             diesel::update(self)
-                .set(blogs::ap_url.eq(self.compute_id(conn)))
+                .set(blogs::ap_url.eq(instance.compute_box(BLOG_PREFIX, self.actor_id.clone(), "")))
                 .get_result::<Blog>(conn).expect("Couldn't update AP URL");
         }
     }
@@ -189,7 +192,7 @@ impl Blog {
                 Link {
                     rel: String::from("http://schemas.google.com/g/2010#updates-from"),
                     mime_type: Some(String::from("application/atom+xml")),
-                    href: self.compute_box(conn, "feed.atom")
+                    href: self.get_instance(conn).compute_box(BLOG_PREFIX, self.actor_id.clone(), "feed.atom")
                 },
                 Link {
                     rel: String::from("self"),
diff --git a/src/models/instance.rs b/src/models/instance.rs
index b627718..b93a92a 100644
--- a/src/models/instance.rs
+++ b/src/models/instance.rs
@@ -2,7 +2,7 @@ use chrono::NaiveDateTime;
 use diesel::{self, QueryDsl, RunQueryDsl, ExpressionMethods, PgConnection};
 use std::iter::Iterator;
 
-use activity_pub::inbox::Inbox;
+use activity_pub::{ap_url, inbox::Inbox};
 use models::users::User;
 use schema::{instances, users};
 
@@ -58,6 +58,16 @@ impl Instance {
             .expect("Couldn't load admins")
             .len() > 0
     }
+
+    pub fn compute_box(&self, prefix: &'static str, name: String, box_name: &'static str) -> String {
+        ap_url(format!(
+            "{instance}/{prefix}/{name}/{box_name}",
+            instance = self.public_domain,
+            prefix = prefix,
+            name = name,
+            box_name = box_name
+        ))
+    }
 }
 
 impl Inbox for Instance {}
diff --git a/src/models/users.rs b/src/models/users.rs
index 8ddf5a3..f55edce 100644
--- a/src/models/users.rs
+++ b/src/models/users.rs
@@ -83,6 +83,8 @@ pub struct NewUser {
     pub shared_inbox_url: Option<String>    
 }
 
+const USER_PREFIX: &'static str = "@";
+
 impl User {
     insert!(users, NewUser);
     get!(users);
@@ -196,21 +198,22 @@ impl User {
     }
 
     pub fn update_boxes(&self, conn: &PgConnection) {
+        let instance = self.get_instance(conn);
         if self.outbox_url.len() == 0 {
             diesel::update(self)
-                .set(users::outbox_url.eq(self.compute_outbox(conn)))
-                .get_result::<User>(conn).expect("Couldn't update outbox URL");                
+                .set(users::outbox_url.eq(instance.compute_box(USER_PREFIX, self.username.clone(), "outbox")))
+                .get_result::<User>(conn).expect("Couldn't update outbox URL");
         }
 
         if self.inbox_url.len() == 0 {
             diesel::update(self)
-                .set(users::inbox_url.eq(self.compute_inbox(conn)))
+                .set(users::inbox_url.eq(instance.compute_box(USER_PREFIX, self.username.clone(), "inbox")))
                 .get_result::<User>(conn).expect("Couldn't update inbox URL");                
         }
 
         if self.ap_url.len() == 0 {
             diesel::update(self)
-                .set(users::ap_url.eq(self.compute_id(conn)))
+                .set(users::ap_url.eq(instance.compute_box(USER_PREFIX, self.username.clone(), "")))
                 .get_result::<User>(conn).expect("Couldn't update AP URL");
         }
 
@@ -340,7 +343,7 @@ impl User {
                 Link {
                     rel: String::from("http://schemas.google.com/g/2010#updates-from"),
                     mime_type: Some(String::from("application/atom+xml")),
-                    href: self.compute_box(conn, "feed.atom")
+                    href: self.get_instance(conn).compute_box(USER_PREFIX, self.username.clone(), "feed.atom")
                 },
                 Link {
                     rel: String::from("self"),