fix: friendlier error for when a subdomain hasn't been configured in dev mode

.changeset/nine-crabs-raise.md

@@ -0,0 +1,5 @@
+---
+"wrangler": patch
+---
+
+fix: friendlier error for when a subdomain hasn't been configured in dev mode

packages/wrangler/src/dev/remote.tsx

@@ -185,7 +185,21 @@ export function useWorker(props: {
       // we want to log the error, but not end the process
       // since it could recover after the developer fixes whatever's wrong
       if ((err as { code: string }).code !== "ABORT_ERR") {
-        logger.error("Error on remote worker:", err);
+        // instead of logging the raw API error to the user,
+        // give them friendly instructions
+        // for error 10063 (workers.dev subdomain required)
+        if (err.code === 10063) {
+          const errorMessage =
+            "Error: You need to register a workers.dev subdomain before running the dev command in remote mode";
+          const solutionMessage =
+            "You can either enable local mode by pressing l, or register a workers.dev subdomain here:";
+          const onboardingLink = `https://dash.cloudflare.com/${accountId}/workers/onboarding`;
+          logger.error(
+            `${errorMessage}\n${solutionMessage}\n${onboardingLink}`
+          );
+        } else {
+          logger.error("Error on remote worker:", err);
+        }
       }
     });