diff --git a/lib/ai/providers/ruxa-image.ts b/lib/ai/providers/ruxa-image.ts
index d448b10..0214eda 100644
--- a/lib/ai/providers/ruxa-image.ts
+++ b/lib/ai/providers/ruxa-image.ts
@@ -154,6 +154,21 @@ function collectImageUrls(payload: any): string[] {
     if (typeof value === "string") {
       if (isLikelyImageUrl(value) || (isImageLikeKey(parentKey) && /^https?:\/\//i.test(value))) {
         urls.add(value);
+        return;
+      }
+
+      const trimmed = value.trim();
+      if (
+        trimmed.length > 1 &&
+        trimmed.length < 200000 &&
+        (trimmed.startsWith("{") || trimmed.startsWith("["))
+      ) {
+        try {
+          const parsed = JSON.parse(trimmed);
+          walk(parsed, parentKey);
+        } catch {
+          // ignore non-JSON strings
+        }
       }
       return;
     }
@@ -244,41 +259,44 @@ async function waitForTaskResult(baseURL: string, apiKey: string, taskId: string
     (id: string) => joinApiPath(baseURL, `/api/v1/tasks/${id}`),
     (id: string) => `${joinApiPath(baseURL, "/api/v1/tasks/query")}?taskId=${encodeURIComponent(id)}`,
   ];
+  let endpointIndex = 0;
 
   for (let attempt = 1; attempt <= POLL_MAX_ATTEMPTS; attempt++) {
-    for (const endpointBuilder of endpointCandidates) {
-      try {
-        const endpoint = endpointBuilder(taskId);
-        const response = await fetch(endpoint, {
-          headers: {
-            Authorization: `Bearer ${apiKey}`,
-            "Content-Type": "application/json",
-          },
-        });
+    try {
+      const endpoint = endpointCandidates[endpointIndex]!(taskId);
+      const response = await fetch(endpoint, {
+        headers: {
+          Authorization: `Bearer ${apiKey}`,
+          "Content-Type": "application/json",
+        },
+      });
 
-        if (!response.ok) {
-          continue;
+      if (!response.ok) {
+        if (response.status === 404 && endpointIndex < endpointCandidates.length - 1) {
+          endpointIndex++;
         }
+        await new Promise((resolve) => setTimeout(resolve, POLL_INTERVAL_MS));
+        continue;
+      }
 
-        const payload = await response.json();
-        const imageUrls = filterSourceImages(collectImageUrls(payload), sourceUrls);
-        const status = extractStatus(payload);
+      const payload = await response.json();
+      const imageUrls = filterSourceImages(collectImageUrls(payload), sourceUrls);
+      const status = extractStatus(payload);
 
-        if (imageUrls.length > 0) {
-          return imageUrls;
-        }
+      if (imageUrls.length > 0) {
+        return imageUrls;
+      }
 
-        if (status && ["failed", "error", "cancelled", "canceled"].includes(status)) {
-          throw new Error(extractErrorMessage(payload));
-        }
+      if (status && ["failed", "error", "cancelled", "canceled"].includes(status)) {
+        throw new Error(extractErrorMessage(payload));
+      }
 
-        if (status && ["success", "succeeded", "completed", "done", "finished"].includes(status)) {
-          throw new Error("任务已完成但未返回图片地址");
-        }
-      } catch (error) {
-        if (error instanceof Error && error.message !== "任务已完成但未返回图片地址") {
-          throw error;
-        }
+      if (status && ["success", "succeeded", "completed", "done", "finished"].includes(status)) {
+        throw new Error("任务已完成但未返回图片地址");
+      }
+    } catch (error) {
+      if (error instanceof Error && error.message !== "任务已完成但未返回图片地址") {
+        throw error;
       }
     }