fix: optionally allow empty subscriptions

gateway-framework/src/subscriptions/subgraph.rs

@@ -19,6 +19,7 @@ pub struct Client {
 impl Client {
     pub async fn create(
         subgraph_client: subgraph_client::Client,
+        allow_empty: bool,
     ) -> watch::Receiver<HashMap<Address, Subscription>> {
         let (tx, mut rx) = watch::channel(Default::default());
         let mut client = Client {
@@ -39,9 +40,11 @@ impl Client {
             }
         });
 
-        rx.wait_for(|subscriptions| !subscriptions.is_empty())
-            .await
-            .unwrap();
+        if !allow_empty {
+            rx.wait_for(|subscriptions| !subscriptions.is_empty())
+                .await
+                .unwrap();
+        }
         rx
     }
 

graph-gateway/src/config.rs

@@ -196,6 +196,9 @@ pub struct Subscriptions {
     /// e.g. If 0.01 USDC (6 decimals) is required per query per minute, then this should be set to
     /// 10000.
     pub rate_per_query: u128,
+    /// Allow startup with no active subscriptions.
+    #[serde(default)]
+    pub allow_empty: bool,
 }
 
 #[serde_as]

graph-gateway/src/main.rs

@@ -485,6 +485,7 @@ async fn init_auth_service(
                 )
                 .with_auth_token(subscriptions.ticket.clone())
                 .build(),
+                subscriptions.allow_empty,
             )
             .await
         }