diff --git a/crates/server/src/main.rs b/crates/server/src/main.rs
index 1603e15..a7b1083 100644
--- a/crates/server/src/main.rs
+++ b/crates/server/src/main.rs
@@ -1,17 +1,14 @@
 use std::{
     path::PathBuf,
-    pin::pin,
     sync::{Arc, LazyLock},
-    time::{Duration, Instant},
 };
 
 use miniserve::{http::StatusCode, Content, Request, Response};
 use serde::{Deserialize, Serialize};
-use tokio::{
-    fs, join,
-    sync::{mpsc, oneshot},
-    task::JoinSet,
-};
+use stateful::StatefulThread;
+use tokio::{fs, join, task::JoinSet};
+
+mod stateful;
 
 async fn index(_req: Request) -> Response {
     let content = include_str!("../index.html").to_string();
@@ -42,55 +39,49 @@ async fn load_docs(paths: Vec<PathBuf>) -> Vec<String> {
     docs
 }
 
-type Payload = (Arc<Vec<String>>, oneshot::Sender<Option<Vec<String>>>);
-
-fn chatbot_thread() -> (mpsc::Sender<Payload>, mpsc::Sender<()>) {
-    let (req_tx, mut req_rx) = mpsc::channel::<Payload>(1024);
-    let (cancel_tx, mut cancel_rx) = mpsc::channel::<()>(1);
-    tokio::spawn(async move {
-        let mut chatbot = chatbot::Chatbot::new(vec![":-)".into(), "^^".into()]);
-        while let Some((messages, responder)) = req_rx.recv().await {
-            let doc_paths = chatbot.retrieval_documents(&messages);
-            let docs = load_docs(doc_paths).await;
-            let mut chat_fut = pin!(chatbot.query_chat(&messages, &docs));
-            let mut cancel_fut = pin!(cancel_rx.recv());
-            let start = Instant::now();
-            loop {
-                let log_fut = tokio::time::sleep(Duration::from_secs(1));
-                tokio::select! {
-                    response = &mut chat_fut => {
-                        responder.send(Some(response)).unwrap();
-                        break;
-                    }
-                    _ = &mut cancel_fut => {
-                        responder.send(None).unwrap();
-                        break;
-                    }
-                    _ = log_fut => {
-                        println!("Waiting for {} seconds", start.elapsed().as_secs());
-                    }
-                }
-            }
-        }
-    });
-    (req_tx, cancel_tx)
+struct LogFunction {
+    logger: chatbot::Logger,
 }
 
-static CHATBOT_THREAD: LazyLock<(mpsc::Sender<Payload>, mpsc::Sender<()>)> =
-    LazyLock::new(chatbot_thread);
+impl stateful::StatefulFunction for LogFunction {
+    type Input = Arc<Vec<String>>;
+    type Output = ();
 
-async fn query_chat(messages: &Arc<Vec<String>>) -> Option<Vec<String>> {
-    let (tx, rx) = oneshot::channel();
-    CHATBOT_THREAD
-        .0
-        .send((Arc::clone(messages), tx))
-        .await
-        .unwrap();
-    rx.await.unwrap()
+    async fn call(&mut self, messages: Self::Input) -> Self::Output {
+        self.logger.append(messages.last().unwrap());
+        self.logger.save().await.unwrap();
+    }
+}
+
+static LOG_THREAD: LazyLock<StatefulThread<LogFunction>> = LazyLock::new(|| {
+    StatefulThread::new(LogFunction {
+        logger: chatbot::Logger::default(),
+    })
+});
+
+struct ChatbotFunction {
+    chatbot: chatbot::Chatbot,
 }
 
+impl stateful::StatefulFunction for ChatbotFunction {
+    type Input = Arc<Vec<String>>;
+    type Output = Vec<String>;
+
+    async fn call(&mut self, messages: Self::Input) -> Self::Output {
+        let doc_paths = self.chatbot.retrieval_documents(&messages);
+        let docs = load_docs(doc_paths).await;
+        self.chatbot.query_chat(&messages, &docs).await
+    }
+}
+
+static CHATBOT_THREAD: LazyLock<StatefulThread<ChatbotFunction>> = LazyLock::new(|| {
+    StatefulThread::new(ChatbotFunction {
+        chatbot: chatbot::Chatbot::new(vec![":-)".into(), "^^".into()]),
+    })
+});
+
 async fn cancel(_req: Request) -> Response {
-    CHATBOT_THREAD.1.send(()).await.unwrap();
+    CHATBOT_THREAD.cancel().await;
     Ok(Content::Html("success".into()))
 }
 
@@ -103,7 +94,11 @@ async fn chat(req: Request) -> Response {
     };
 
     let messages = Arc::new(data.messages);
-    let (i, responses_opt) = join!(chatbot::gen_random_number(), query_chat(&messages));
+    let (i, responses_opt, _) = join!(
+        chatbot::gen_random_number(),
+        CHATBOT_THREAD.call(Arc::clone(&messages)),
+        LOG_THREAD.call(Arc::clone(&messages))
+    );
 
     let response = match responses_opt {
         Some(mut responses) => {
diff --git a/crates/server/src/stateful.rs b/crates/server/src/stateful.rs
new file mode 100644
index 0000000..bd3a199
--- /dev/null
+++ b/crates/server/src/stateful.rs
@@ -0,0 +1,73 @@
+use std::{
+    fmt::Debug,
+    future::Future,
+    pin::pin,
+    time::{Duration, Instant},
+};
+
+use tokio::{
+    sync::{mpsc, oneshot},
+    task::JoinHandle,
+};
+
+pub trait StatefulFunction: Send + 'static {
+    type Input: Send;
+    type Output: Send + Debug;
+    fn call(&mut self, input: Self::Input) -> impl Future<Output = Self::Output> + Send;
+}
+
+type Payload<F> = (
+    <F as StatefulFunction>::Input,
+    oneshot::Sender<Option<<F as StatefulFunction>::Output>>,
+);
+
+pub struct StatefulThread<F: StatefulFunction> {
+    _handle: JoinHandle<()>,
+    input_tx: mpsc::Sender<Payload<F>>,
+    cancel_tx: mpsc::Sender<()>,
+}
+
+impl<F: StatefulFunction> StatefulThread<F> {
+    pub fn new(mut func: F) -> Self {
+        let (input_tx, mut input_rx) = mpsc::channel::<Payload<F>>(1024);
+        let (cancel_tx, mut cancel_rx) = mpsc::channel::<()>(1);
+        let _handle = tokio::spawn(async move {
+            while let Some((input, responder)) = input_rx.recv().await {
+                let mut output_fut = pin!(func.call(input));
+                let mut cancel_fut = pin!(cancel_rx.recv());
+                let start = Instant::now();
+                loop {
+                    let log_fut = tokio::time::sleep(Duration::from_secs(1));
+                    tokio::select! {
+                        response = &mut output_fut => {
+                            responder.send(Some(response)).unwrap();
+                            break;
+                        }
+                        _ = &mut cancel_fut => {
+                            responder.send(None).unwrap();
+                            break;
+                        }
+                        _ = log_fut => {
+                            println!("Waiting for {} seconds", start.elapsed().as_secs());
+                        }
+                    }
+                }
+            }
+        });
+        StatefulThread {
+            _handle,
+            input_tx,
+            cancel_tx,
+        }
+    }
+
+    pub async fn call(&self, input: F::Input) -> Option<F::Output> {
+        let (tx, rx) = oneshot::channel();
+        self.input_tx.send((input, tx)).await.unwrap();
+        rx.await.unwrap()
+    }
+
+    pub async fn cancel(&self) {
+        self.cancel_tx.send(()).await.unwrap();
+    }
+}