diff --git a/CHANGELOG.md b/CHANGELOG.md
index ce57f29e3a7..dcce92716c8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -52,6 +52,7 @@ Docs: https://docs.openclaw.ai
 
 ### Fixes
 
+- Agents/OpenAI: default direct OpenAI Responses models to the SSE transport instead of WebSocket auto-selection, preventing pi runtime chat turns from hanging on servers where the WebSocket path stalls while the OpenAI HTTP stream works. Thanks @vincentkoc.
 - CLI/update: disable and skip plugins that fail package-update plugin sync, so a broken npm/ClawHub/git/marketplace plugin cannot turn a successful OpenClaw package update into a failed update result. Thanks @vincentkoc.
 - CLI/update: use an absolute POSIX npm script shell during package-manager updates, so restricted PATH environments can still run dependency lifecycle scripts while updating from `--tag main`. Fixes #77530. Thanks @PeterTremonti.
 - Diagnostics: grant the internal diagnostics event bus to official installed diagnostics exporter plugins, so npm-installed `@openclaw/diagnostics-prometheus` can emit metrics without broadening the capability to arbitrary global plugins. Fixes #76628. Thanks @RayWoo.
diff --git a/extensions/openai/openai-provider.test.ts b/extensions/openai/openai-provider.test.ts
index 3cb2872f5f0..24b96524566 100644
--- a/extensions/openai/openai-provider.test.ts
+++ b/extensions/openai/openai-provider.test.ts
@@ -508,9 +508,9 @@ describe("buildOpenAIProvider", () => {
     });
 
     expect(extraParams).toMatchObject({
-      transport: "auto",
-      openaiWsWarmup: true,
+      transport: "sse",
     });
+    expect(extraParams?.openaiWsWarmup).toBeUndefined();
     expect(result.payload.store).toBe(true);
     expect(result.payload.context_management).toEqual([
       { type: "compaction", compact_threshold: 140_000 },
diff --git a/extensions/openai/openai-provider.ts b/extensions/openai/openai-provider.ts
index 969b04ed5dc..76503bb293d 100644
--- a/extensions/openai/openai-provider.ts
+++ b/extensions/openai/openai-provider.ts
@@ -227,7 +227,7 @@ export function buildOpenAIProvider(): ProviderPlugin {
       shouldUseOpenAIResponsesTransport({ provider, api, baseUrl })
         ? { api: "openai-responses", baseUrl }
         : undefined,
-    ...buildOpenAIResponsesProviderHooks({ openaiWsWarmup: true }),
+    ...buildOpenAIResponsesProviderHooks({ transport: "sse" }),
     matchesContextOverflowError: ({ errorMessage }) =>
       /content_filter.*(?:prompt|input).*(?:too long|exceed)/i.test(errorMessage),
     resolveReasoningOutputMode: () => "native",
diff --git a/extensions/openai/shared.ts b/extensions/openai/shared.ts
index c2b43cbe9be..143737f3d9d 100644
--- a/extensions/openai/shared.ts
+++ b/extensions/openai/shared.ts
@@ -50,10 +50,11 @@ function hasSupportedOpenAIResponsesTransport(
 
 function defaultOpenAIResponsesExtraParams(
   extraParams: Record<string, unknown> | undefined,
-  options?: { openaiWsWarmup?: boolean },
+  options?: { openaiWsWarmup?: boolean; transport?: "auto" | "sse" | "websocket" },
 ): Record<string, unknown> | undefined {
   const hasSupportedTransport = hasSupportedOpenAIResponsesTransport(extraParams?.transport);
   const hasExplicitWarmup = typeof extraParams?.openaiWsWarmup === "boolean";
+  const defaultTransport = options?.transport ?? "auto";
   const shouldDefaultWarmup = options?.openaiWsWarmup === true;
   if (hasSupportedTransport && (!shouldDefaultWarmup || hasExplicitWarmup)) {
     return extraParams;
@@ -61,7 +62,7 @@ function defaultOpenAIResponsesExtraParams(
 
   return {
     ...extraParams,
-    ...(hasSupportedTransport ? {} : { transport: "auto" }),
+    ...(hasSupportedTransport ? {} : { transport: defaultTransport }),
     ...(shouldDefaultWarmup && !hasExplicitWarmup ? { openaiWsWarmup: true } : {}),
   };
 }
@@ -93,6 +94,7 @@ const wrapOpenAIResponsesProviderStreamFn: NonNullable<
 
 export function buildOpenAIResponsesProviderHooks(options?: {
   openaiWsWarmup?: boolean;
+  transport?: "auto" | "sse" | "websocket";
 }): OpenAIResponsesProviderHooks {
   return {
     buildReplayPolicy: buildOpenAIReplayPolicy,