diff --git a/src/main.rs b/src/main.rs
index 62c1257..cea7ca0 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -2,13 +2,13 @@ use std::collections::HashMap;
 use std::sync::Arc;
 
 use cookie::{Cookie, SameSite};
-use futures::TryFutureExt;
 use log::{debug, error, info, trace};
-use sessions::{Session, SessionStatus, Storable};
+use sessions::Session;
 use warp::{Filter, Rejection, Reply};
 use warp::http::{StatusCode, Uri};
 
-const SESSION_HEADER: &str = "Spectrum-Session";
+mod session;
+use crate::session::{NoSession, SESSION_HEADER, SESSION_NAME, SessionPolicy, with_session};
 
 #[tokio::main]
 async fn main() {
@@ -78,44 +78,6 @@ where From: 'static,
   })
 }
 
-#[derive(Debug, Clone, Copy)]
-enum SessionPolicy {
-  Existing,
-  AllowNew
-}
-
-const SESSION_NAME: &str = "name";
-
-fn with_session(store: Arc<impl Storable>,
-                policy: SessionPolicy) -> impl Filter<Extract = (Session,),
-                                                      Error = Rejection> + Clone {
-  warp::cookie::cookie(SESSION_HEADER)
-    .and_then(move |session_id: String| {
-      trace!("Looking up session: {}", session_id);
-      let store = store.clone();  // pending async reqs allowed to outlive returned Filter
-      async move {
-        let session = store.get(&session_id).await?;
-        session.set_id(session_id)?;
-        Ok(session)
-      }
-    }.map_err(|err: std::io::Error| warp::reject::custom(ServerError(Box::new(err)))))
-    .or_else(clarify_error::<_, warp::reject::MissingCookie, NoSession>)  // Has cookies, but not session cookie
-    .or_else(clarify_error::<_, warp::reject::InvalidHeader, NoSession>)  // No cookies at all
-    .and_then(move |session: Session| async move {
-      match (session.status(), policy) {
-        (Ok(SessionStatus::Existed), _ )
-          // Session exists, but name might not be set yet
-          if session.get::<String>(SESSION_NAME)
-              .map_or(false, |name| name.filter(|name| !name.is_empty()).is_some()) => Ok(session),
-        (Ok(SessionStatus::Existed), _ )                      => Err(warp::reject::custom(BadName)),
-        (Ok(SessionStatus::Created), SessionPolicy::AllowNew) => Ok(session),
-        (Ok(SessionStatus::Created), _)                       => Err(warp::reject::custom(NoSession)),
-        (Err(e), _) => Err(warp::reject::custom(ServerError(Box::new(e)))),
-        _           => Err(warp::reject::custom(NoSession))
-      }
-    })
-}
-
 #[derive(Debug, Default)]
 struct BadName;
 impl warp::reject::Reject for BadName {}
@@ -135,10 +97,6 @@ async fn handle_reject(err: Rejection) -> Result<Box<dyn Reply>, Rejection> {
 struct ServerError(Box<dyn std::error::Error + Send + Sync>);
 impl warp::reject::Reject for ServerError {}
 
-#[derive(Debug, Default)]
-struct NoSession;
-impl warp::reject::Reject for NoSession {}
-
 async fn handle_no_session(err: Rejection) -> Result<impl Reply, Rejection> {
   match err.find() {
     Some(NoSession) => {
diff --git a/src/session.rs b/src/session.rs
new file mode 100644
index 0000000..bdc6836
--- /dev/null
+++ b/src/session.rs
@@ -0,0 +1,51 @@
+use std::sync::Arc;
+
+use futures::TryFutureExt;
+use log::trace;
+use sessions::{Session, SessionStatus, Storable};
+use warp::{Filter, Rejection};
+
+use crate::{BadName, clarify_error, ServerError};
+
+pub const SESSION_HEADER: &str = "Spectrum-Session";
+pub const SESSION_NAME: &str = "name";
+
+#[derive(Debug, Clone, Copy)]
+pub enum SessionPolicy {
+  Existing,
+  AllowNew
+}
+
+pub fn with_session(store: Arc<impl Storable>,
+                policy: SessionPolicy) -> impl Filter<Extract = (Session,),
+                                                      Error = Rejection> + Clone {
+  warp::cookie::cookie(SESSION_HEADER)
+    .and_then(move |session_id: String| {
+      trace!("Looking up session: {}", session_id);
+      let store = store.clone();  // pending async reqs allowed to outlive returned Filter
+      async move {
+        let session = store.get(&session_id).await?;
+        session.set_id(session_id)?;
+        Ok(session)
+      }
+    }.map_err(|err: std::io::Error| warp::reject::custom(ServerError(Box::new(err)))))
+    .or_else(clarify_error::<_, warp::reject::MissingCookie, NoSession>)  // Has cookies, but not session cookie
+    .or_else(clarify_error::<_, warp::reject::InvalidHeader, NoSession>)  // No cookies at all
+    .and_then(move |session: Session| async move {
+      match (session.status(), policy) {
+        (Ok(SessionStatus::Existed), _ )
+          // Session exists, but name might not be set yet
+          if session.get::<String>(SESSION_NAME)
+              .map_or(false, |name| name.filter(|name| !name.is_empty()).is_some()) => Ok(session),
+        (Ok(SessionStatus::Existed), _ )                      => Err(warp::reject::custom(BadName)),
+        (Ok(SessionStatus::Created), SessionPolicy::AllowNew) => Ok(session),
+        (Ok(SessionStatus::Created), _)                       => Err(warp::reject::custom(NoSession)),
+        (Err(e), _) => Err(warp::reject::custom(ServerError(Box::new(e)))),
+        _           => Err(warp::reject::custom(NoSession))
+      }
+    })
+}
+
+#[derive(Debug, Default)]
+pub struct NoSession;
+impl warp::reject::Reject for NoSession {}