diff --git a/server/_shared/redis.ts b/server/_shared/redis.ts
index be9746d2f4..f103ec1f07 100644
--- a/server/_shared/redis.ts
+++ b/server/_shared/redis.ts
@@ -81,11 +81,18 @@ export async function setCachedJson(key: string, value: unknown, ttlSeconds: num
   if (!url || !token) return;
   try {
     // Atomic SET with EX — single call avoids race between SET and EXPIRE (C-3 fix)
-    await fetch(`${url}/set/${encodeURIComponent(prefixKey(key))}/${encodeURIComponent(JSON.stringify(value))}/EX/${ttlSeconds}`, {
+    const resp = await fetch(`${url}/`, {
       method: 'POST',
-      headers: { Authorization: `Bearer ${token}` },
-      signal: AbortSignal.timeout(REDIS_OP_TIMEOUT_MS),
+      headers: {
+        Authorization: `Bearer ${token}`,
+        'Content-Type': 'application/json',
+      },
+      body: JSON.stringify(['SET', prefixKey(key), JSON.stringify(value), 'EX', String(ttlSeconds)]),
+      signal: AbortSignal.timeout(REDIS_PIPELINE_TIMEOUT_MS),
     });
+    if (!resp.ok) {
+      console.warn(`[redis] setCachedJson HTTP ${resp.status}`);
+    }
   } catch (err) {
     console.warn('[redis] setCachedJson failed:', errMsg(err));
   }