diff --git a/src/database/mod.rs b/src/database/mod.rs
index f3e2bde..2678305 100644
--- a/src/database/mod.rs
+++ b/src/database/mod.rs
@@ -1,2 +1,5 @@
 pub mod unversioned;
 pub mod v1;
+
+pub const SCHEMA_VERSION: unversioned::global::schema_version::V = 1;
+pub use self::v1 as latest;
diff --git a/src/database/unversioned.rs b/src/database/unversioned.rs
index edf4205..0acd674 100644
--- a/src/database/unversioned.rs
+++ b/src/database/unversioned.rs
@@ -1,6 +1,6 @@
 pub mod global {
     pub mod schema_version {
         pub const K: &str = "SCHEMA_VERSION";
-        pub type V = (u32, u32, u32);
+        pub type V = u32;
     }
 }
diff --git a/src/database/v1.rs b/src/database/v1.rs
index 4416d21..abb0e00 100644
--- a/src/database/v1.rs
+++ b/src/database/v1.rs
@@ -35,8 +35,13 @@ pub mod trees {
 
         #[derive(Debug, Clone, Serialize, Deserialize)]
         pub struct V {
+            /// The UUID of the category to which this session belongs
             pub category: trees::categories::K,
+
+            /// The time when this session was started
             pub started: NaiveDateTime,
+
+            /// The time when this session was ended
             pub ended: NaiveDateTime,
         }
     }
diff --git a/src/main.rs b/src/main.rs
index 688e0a6..f0bf41c 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -4,6 +4,8 @@ mod handlebars_util;
 mod routes;
 mod status_json;
 
+use bincode::{deserialize, serialize};
+use database::{unversioned::global::schema_version, SCHEMA_VERSION};
 use dotenv::dotenv;
 use rocket_contrib::serve::StaticFiles;
 use rocket_contrib::templates::Template;
@@ -15,6 +17,21 @@ fn main() -> io::Result<()> {
     let db_path = env::var("DB_PATH").expect("DB_PATH not set");
 
     let sled = sled::open(db_path)?;
+    match sled.insert(
+        serialize(schema_version::K).unwrap(),
+        serialize(&SCHEMA_VERSION).unwrap(),
+    )? {
+        Some(prev_schema_version) => {
+            let prev_schema_version: schema_version::V = deserialize(&prev_schema_version).unwrap();
+            println!(
+                "Schema version: {}, previously: {}",
+                SCHEMA_VERSION, prev_schema_version
+            );
+        }
+        None => {
+            println!("Schema version: {}, previously: None", SCHEMA_VERSION);
+        }
+    }
 
     let rocket = rocket::ignite()
         .attach(Template::custom(|engines| {
@@ -28,8 +45,9 @@ fn main() -> io::Result<()> {
                 routes::pages::index,
                 routes::pages::history,
                 routes::api::create_category,
-                routes::api::activate_category,
-                routes::api::deactivate_category,
+                routes::api::start_session,
+                routes::api::end_session,
+                routes::api::delete_session,
             ],
         );
 
diff --git a/src/routes/api.rs b/src/routes/api.rs
index e60b454..98d765d 100644
--- a/src/routes/api.rs
+++ b/src/routes/api.rs
@@ -1,10 +1,12 @@
-use crate::database::v1::trees::{categories, past_sessions};
+use crate::database::latest::trees::{categories, past_sessions};
+use crate::routes::pages;
 use crate::status_json::StatusJson;
 use bincode::{deserialize, serialize};
 use chrono::{Duration, Utc};
 use rocket::http::Status;
 use rocket::request::{Form, FromForm};
-use rocket::{post, State};
+use rocket::response::Redirect;
+use rocket::{post, uri, State};
 use sled::Transactional;
 use uuid::Uuid;
 
@@ -34,23 +36,23 @@ pub fn create_category(
     Ok(Status::Ok.into())
 }
 
-#[post("/set_category/<category_uuid>/active")]
-pub fn activate_category(
+#[post("/category/<category_uuid>/start_session")]
+pub fn start_session(
     category_uuid: String,
     db: State<'_, sled::Db>,
 ) -> Result<StatusJson, StatusJson> {
-    toggle_category(category_uuid, true, db)
+    toggle_category_session(category_uuid, true, db)
 }
 
-#[post("/set_category/<category_uuid>/inactive")]
-pub fn deactivate_category(
+#[post("/category/<category_uuid>/end_session")]
+pub fn end_session(
     category_uuid: String,
     db: State<'_, sled::Db>,
 ) -> Result<StatusJson, StatusJson> {
-    toggle_category(category_uuid, false, db)
+    toggle_category_session(category_uuid, false, db)
 }
 
-pub fn toggle_category(
+pub fn toggle_category_session(
     category_uuid: String,
     set_active: bool,
     db: State<'_, sled::Db>,
@@ -101,3 +103,30 @@ pub fn toggle_category(
         },
     )??)
 }
+
+#[post("/session/<session_uuid>/delete")]
+pub fn delete_session(
+    session_uuid: String,
+    db: State<'_, sled::Db>,
+) -> Result<Redirect, StatusJson> {
+    let session_uuid = Uuid::parse_str(&session_uuid)?;
+    let session_uuid_s = sled::IVec::from(serialize(&session_uuid)?);
+
+    let past_sessions_tree = db.open_tree(past_sessions::NAME)?;
+
+    match past_sessions_tree.remove(session_uuid_s)? {
+        Some(_) => Ok(Redirect::to(uri!(pages::history))),
+        None => Err(Status::NotFound.into()),
+    }
+
+    // TODO: mark as deleted instead of removing
+    // Ok(past_sessions_tree.transaction(|tx_past_sessions| {
+    //     match tx_past_sessions.get(&session_uuid_s)? {
+    //         None => return Ok(Err(Status::NotFound)),
+    //         Some(data) => {
+    //             let mut past_session: past_sessions::V = deserialize(&data).unwrap();
+    //         }
+    //     }
+    //     Ok(Ok(Redirect::to(uri!(pages::history))))
+    // })??)
+}
diff --git a/src/routes/pages.rs b/src/routes/pages.rs
index 67a71c5..9d24b95 100644
--- a/src/routes/pages.rs
+++ b/src/routes/pages.rs
@@ -1,4 +1,4 @@
-use crate::database::v1::trees::{categories, past_sessions};
+use crate::database::latest::trees::{categories, past_sessions};
 use crate::status_json::StatusJson;
 use bincode::deserialize;
 use rocket::{get, State};
@@ -35,6 +35,7 @@ pub fn history(db: State<'_, sled::Db>) -> Result<Template, StatusJson> {
     struct HistoryEntryContext {
         category: categories::V,
         session: past_sessions::V,
+        session_id: Uuid,
         duration: Duration,
     }
 
@@ -60,19 +61,17 @@ pub fn history(db: State<'_, sled::Db>) -> Result<Template, StatusJson> {
         })
         .collect::<Result<Result<_, _>, _>>()??;
 
-    let mut context = dbg!(TemplateContext {
+    let mut context = TemplateContext {
         entries: past_sessions
             .into_iter()
-            .map(|(_, session)| {
-                let category = categories.get(&session.category).unwrap().clone();
-                HistoryEntryContext {
-                    duration: (session.ended - session.started).to_std().unwrap(),
-                    category,
-                    session,
-                }
+            .map(|(session_id, session)| HistoryEntryContext {
+                duration: (session.ended - session.started).to_std().unwrap(),
+                category: categories.get(&session.category).unwrap().clone(),
+                session,
+                session_id,
             })
             .collect(),
-    });
+    };
 
     // Newest entries first
     context.entries.sort_by_key(|entry| entry.session.started);
diff --git a/src/status_json.rs b/src/status_json.rs
index c92d090..f07abb8 100644
--- a/src/status_json.rs
+++ b/src/status_json.rs
@@ -1,3 +1,5 @@
+#![allow(dead_code)]
+
 use duplicate::duplicate;
 use log::{info, warn};
 use rocket::http::Status;
diff --git a/static/styles.css b/static/styles.css
index 7ab328c..6fd26ec 100644
--- a/static/styles.css
+++ b/static/styles.css
@@ -100,3 +100,6 @@ ul.striped_list > li:nth-of-type(odd) {
     color: #9f2727;
 }
 
+.history_entry_delete_button {
+    color: #aa0000;
+}
diff --git a/templates/history.hbs b/templates/history.hbs
index 6d2acc9..4961921 100644
--- a/templates/history.hbs
+++ b/templates/history.hbs
@@ -17,13 +17,16 @@
         <ul class="striped_list">
         {{#each entries}}
             <li class="history_entry">
-                <span class="history_entry_category">{{this.category.name}}</span>
-                <span> for </span>
-                <span class="history_entry_duration">{{pretty_seconds this.duration.secs}}</span>
-                <span> from </span>
-                <span class="history_entry_started">{{pretty_datetime this.session.started}}</span>
-                <span> to </span>
-                <span class="history_entry_ended">{{pretty_datetime this.session.ended}}</span>
+                <form action="/session/{{this.session_id}}/delete" method="post">
+                    <span class="history_entry_category">{{this.category.name}}</span>
+                    <span> under </span>
+                    <span class="history_entry_duration">{{pretty_seconds this.duration.secs}}</span>
+                    <span> från </span>
+                    <span class="history_entry_started">{{pretty_datetime this.session.started}}</span>
+                    <span> tills </span>
+                    <span class="history_entry_ended">{{pretty_datetime this.session.ended}}</span>
+                    <button type="submit" class="history_entry_delete_button">✕</button>
+                </form>
             </li>
         {{/each}}
         </ul>
diff --git a/templates/index.hbs b/templates/index.hbs
index e8edd57..69d7d3c 100644
--- a/templates/index.hbs
+++ b/templates/index.hbs
@@ -20,10 +20,10 @@
                 // Get the corresponding route to activate/inactivate the category
                 let url;
                 if(active) {
-                    url = "/set_category/" + id + "/inactive";
+                    url = "/category/" + id + "/end_session";
                     cl.remove(toggled_class);
                 } else {
-                    url = "/set_category/" + id + "/active";
+                    url = "/category/" + id + "/start_session";
                     cl.add(toggled_class);
                 }
 
@@ -42,10 +42,6 @@
     <body>
         <h1 class="title">stl</h1>
 
-        {{#each categories}}
-            <form action="/toggle_category/{{this.0}}" method="post" id="{{this.0}}"></form>
-        {{/each}}
-
         <ul class="striped_list">
         {{#each categories}}
             <li class="category_entry">