diff --git a/extensions/openai/realtime-quicksilver-wire.test.ts b/extensions/openai/realtime-quicksilver-wire.test.ts
index 1b6c03830d79..170d6637308f 100644
--- a/extensions/openai/realtime-quicksilver-wire.test.ts
+++ b/extensions/openai/realtime-quicksilver-wire.test.ts
@@ -315,4 +315,37 @@ describe("GPT-Live call creation", () => {
       message: "GPT-Live call creation returned an empty SDP answer",
     });
   });
+
+  it.each([
+    {
+      label: "GPT-Live",
+      auth: { type: "oauth" as const, token: "oauth-token", accountId: "acct-1" },
+      model: "gpt-live-1-codex",
+      location: "/v1/live/rtc_oversized_answer",
+    },
+    {
+      label: "OpenAI Realtime",
+      auth: { type: "api-key" as const, token: "platform-key" },
+      model: "gpt-realtime-2.1",
+      location: undefined,
+    },
+  ])("rejects an oversized streaming $label SDP answer", async (testCase) => {
+    const fetchImpl = vi.fn(
+      async () =>
+        new Response(`v=answer\r\n${"x".repeat(256 * 1024)}`, {
+          status: 201,
+          headers: testCase.location ? { Location: testCase.location } : undefined,
+        }),
+    );
+
+    await expect(
+      createOpenAIQuicksilverCall({
+        auth: testCase.auth,
+        requestIds: createRequestIds(`oversized-answer-${testCase.label}`),
+        sdp: "v=offer\r\n",
+        session: buildOpenAIQuicksilverSession({ model: testCase.model }),
+        fetchImpl: fetchImpl as unknown as typeof fetch,
+      }),
+    ).rejects.toThrow(`${testCase.label} SDP answer: text response exceeds 262144 bytes`);
+  });
 });
diff --git a/extensions/openai/realtime-quicksilver-wire.ts b/extensions/openai/realtime-quicksilver-wire.ts
index b8d31136e113..7511716faefa 100644
--- a/extensions/openai/realtime-quicksilver-wire.ts
+++ b/extensions/openai/realtime-quicksilver-wire.ts
@@ -1,6 +1,7 @@
 // GPT-Live frameless session, call-creation, and sideband event wire contracts.
 import { randomBytes } from "node:crypto";
 import {
+  readProviderTextResponse,
   readResponseTextLimited,
   resolveProviderRequestHeaders,
 } from "openclaw/plugin-sdk/provider-http";
@@ -15,6 +16,7 @@ const OPENAI_QUICKSILVER_CALL_URL = "https://api.openai.com/v1/live";
 const OPENAI_REALTIME_CALL_URL = "https://api.openai.com/v1/realtime/calls";
 const OPENAI_REALTIME_ERROR_BODY_MAX_BYTES = 16 * 1024;
 const OPENAI_REALTIME_ERROR_DETAIL_MAX_CHARS = 500;
+const OPENAI_REALTIME_SDP_ANSWER_MAX_BYTES = 256 * 1024;
 const OPENAI_GPT_LIVE_WAITLIST_URL = "https://openai.com/form/gpt-live-1-in-the-api/";
 
 const OPENAI_QUICKSILVER_VOICES = [
@@ -428,7 +430,11 @@ export async function createOpenAIQuicksilverCall(params: {
       response.status,
     );
   }
-  const answerSdp = await response.text();
+  const answerSdp = await readProviderTextResponse(
+    response,
+    `${isGptLive ? "GPT-Live" : "OpenAI Realtime"} SDP answer`,
+    { maxBytes: OPENAI_REALTIME_SDP_ANSWER_MAX_BYTES },
+  );
   if (!answerSdp.trim()) {
     throw new OpenAIQuicksilverCallError(
       `${isGptLive ? "GPT-Live" : "OpenAI Realtime"} call creation returned an empty SDP answer`,