diff --git a/Cargo.lock b/Cargo.lock
index a334111..afeab09 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -239,7 +239,7 @@ checksum = "613afe47fcd5fac7ccf1db93babcb082c5994d996f20b8b159f2ad1658eb5724"
 
 [[package]]
 name = "charge-controller-supervisor"
-version = "1.9.9-pre-4"
+version = "1.9.9-pre-5"
 dependencies = [
  "chrono",
  "clap",
@@ -2201,7 +2201,7 @@ dependencies = [
 
 [[package]]
 name = "tesla-charge-controller"
-version = "1.9.9-pre-4"
+version = "1.9.9-pre-5"
 dependencies = [
  "chrono",
  "clap",
diff --git a/Cargo.toml b/Cargo.toml
index 5995459..fa4416d 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -4,7 +4,7 @@ default-members = ["charge-controller-supervisor"]
 resolver = "2"
 
 [workspace.package]
-version = "1.9.9-pre-4"
+version = "1.9.9-pre-5"
 
 [workspace.lints.clippy]
 pedantic = "warn"
diff --git a/charge-controller-supervisor/src/main.rs b/charge-controller-supervisor/src/main.rs
index 10f8e06..1444cd6 100644
--- a/charge-controller-supervisor/src/main.rs
+++ b/charge-controller-supervisor/src/main.rs
@@ -82,7 +82,7 @@ async fn watch(args: Args) -> eyre::Result<()> {
         }
     }
 
-    let server = web::rocket(web::ServerState::new(map));
+    let server = web::rocket(web::ServerState::new(config.primary_charge_controller, map));
     let server_task = tokio::task::spawn(server.launch());
 
     tokio::select! {
diff --git a/charge-controller-supervisor/src/web.rs b/charge-controller-supervisor/src/web.rs
index d603f0d..c80ab7b 100644
--- a/charge-controller-supervisor/src/web.rs
+++ b/charge-controller-supervisor/src/web.rs
@@ -1,6 +1,7 @@
 use rocket::{get, routes, serde::json::Json, State};
 
 pub struct ServerState {
+    primary_name: String,
     map: std::collections::HashMap<
         String,
         std::sync::Arc<tokio::sync::RwLock<crate::controller::CommonData>>,
@@ -9,19 +10,27 @@ pub struct ServerState {
 
 impl ServerState {
     pub fn new(
+        primary_name: String,
         map: std::collections::HashMap<
             String,
             std::sync::Arc<tokio::sync::RwLock<crate::controller::CommonData>>,
         >,
     ) -> Self {
-        Self { map }
+        Self { primary_name, map }
     }
 }
 
 pub fn rocket(state: ServerState) -> rocket::Rocket<rocket::Build> {
-    rocket::build()
-        .manage(state)
-        .mount("/", routes![metrics, interfaces, all_interfaces, interface])
+    rocket::build().manage(state).mount(
+        "/",
+        routes![
+            metrics,
+            interfaces,
+            all_interfaces,
+            primary_interface,
+            interface
+        ],
+    )
 }
 
 #[get("/interfaces")]
@@ -29,6 +38,21 @@ fn interfaces(state: &State<ServerState>) -> Json<Vec<String>> {
     Json(state.map.keys().cloned().collect())
 }
 
+#[get("/interfaces/primary")]
+async fn primary_interface(
+    state: &State<ServerState>,
+) -> Result<Json<crate::controller::CommonData>, ServerError> {
+    let s = state
+        .map
+        .get(&state.primary_name)
+        .ok_or(ServerError::InvalidPrimaryName)?
+        .read()
+        .await
+        .clone();
+
+    Ok(Json(s))
+}
+
 #[get("/interfaces/data")]
 async fn all_interfaces(
     state: &State<ServerState>,
@@ -68,6 +92,7 @@ fn metrics() -> Result<String, ServerError> {
 enum ServerError {
     Prometheus,
     NotFound,
+    InvalidPrimaryName,
 }
 
 impl From<prometheus::Error> for ServerError {
@@ -79,8 +104,9 @@ impl From<prometheus::Error> for ServerError {
 impl<'a> rocket::response::Responder<'a, 'a> for ServerError {
     fn respond_to(self, _: &'a rocket::Request<'_>) -> rocket::response::Result<'a> {
         Err(match self {
+            Self::Prometheus => rocket::http::Status::InternalServerError,
             Self::NotFound => rocket::http::Status::NotFound,
-            ServerError::Prometheus => rocket::http::Status::InternalServerError,
+            Self::InvalidPrimaryName => rocket::http::Status::ServiceUnavailable,
         })
     }
 }