Route Pages preview hosts to workers.dev agent API.

Allow *.pages.dev origins in the agent Worker CORS so design chat works when the custom domain is blocked.

Co-authored-by: Cursor <cursoragent@cursor.com>

Author: 2 people

src/app/globals.css

@@ -1065,10 +1065,10 @@
   .element-chat-popup-thread {
     display: flex;
     flex-direction: column;
-    gap: 4px;
+    gap: 6px;
     max-height: 160px;
     overflow-y: auto;
-    padding: 2px 14px 0;
+    padding: 4px 14px 14px;
   }
 
   .element-chat-popup-line {
@@ -1084,10 +1084,12 @@
 
   .element-chat-popup-line--assistant {
     color: rgba(17, 17, 17, 0.55);
+    padding-bottom: 2px;
   }
 
   .element-chat-popup-line--status {
     color: rgba(17, 17, 17, 0.35);
+    padding-bottom: 2px;
   }
 
   .element-chat-popup-line--error {

src/lib/agent-client.ts

@@ -4,11 +4,27 @@ import type { ElementContext } from "./element-context";
 const SESSION_ID_KEY = "popped.dev:agent-session-id";
 const AGENT_ID_KEY = "popped.dev:agent-id";
 
-const API_BASE =
-  (typeof process !== "undefined" && process.env.NEXT_PUBLIC_AGENT_API_URL) || "";
+/** Pages hosts have no /api — call the Worker directly (works when popped.dev is blocked). */
+const PAGES_AGENT_API = "https://popped-dev-agent-api.parse-nip.workers.dev";
+
+function isPagesDevHost(hostname: string): boolean {
+  return hostname === "popped-dev.pages.dev" || hostname.endsWith("--popped-dev.pages.dev");
+}
+
+function getApiBase(): string {
+  const fromEnv =
+    typeof process !== "undefined" ? process.env.NEXT_PUBLIC_AGENT_API_URL?.trim() : "";
+  if (fromEnv) return fromEnv;
+
+  if (typeof window !== "undefined" && isPagesDevHost(window.location.hostname)) {
+    return PAGES_AGENT_API;
+  }
+
+  return "";
+}
 
 function apiUrl(path: string): string {
-  return `${API_BASE}${path}`;
+  return `${getApiBase()}${path}`;
 }
 
 export function getContributorName(): string {

workers/agent-api/src/index.ts

@@ -36,6 +36,13 @@ app.use(
       ) {
         return origin;
       }
+      // Cloudflare Pages default + branch preview URLs (no Worker on *.pages.dev).
+      if (
+        origin === "https://popped-dev.pages.dev" ||
+        /^https:\/\/[^/]+--popped-dev\.pages\.dev$/.test(origin)
+      ) {
+        return origin;
+      }
       return c.env.CORS_ORIGIN || "https://popped.dev";
     },
     allowMethods: ["GET", "POST", "OPTIONS"],