Using static client data as DCR fallback

client/src/lib/oauth-state-machine.ts

@@ -88,16 +88,34 @@ export const oauthTransitions: Record<OAuthStep, StateTransition> = {
         clientMetadata.scope = scopesSupported.join(" ");
       }
 
-      const fullInformation = await registerClient(context.serverUrl, {
-        metadata,
-        clientMetadata,
-      });
+      // Try DCR first, with static client as fallback
+      try {
+        const fullInformation = await registerClient(context.serverUrl, {
+          metadata,
+          clientMetadata,
+        });
 
-      context.provider.saveClientInformation(fullInformation);
-      context.updateState({
-        oauthClientInfo: fullInformation,
-        oauthStep: "authorization_redirect",
-      });
+        context.provider.saveClientInformation(fullInformation);
+        context.updateState({
+          oauthClientInfo: fullInformation,
+          oauthStep: "authorization_redirect",
+        });
+        console.log({ fullInformation });
+        return;
+      } catch (dcrError) {
+        console.error(dcrError);
+
+        // DCR failed, fallback to preregistered client
+        const existingClientInfo = await context.provider.clientInformation();
+        if (!existingClientInfo) {
+          console.error("Neither dynamic client registration or preregistered client information was found");
+          throw dcrError;
+        }
+        context.updateState({
+          oauthClientInfo: existingClientInfo,
+          oauthStep: "authorization_redirect",
+        });
+      }
     },
   },