diff --git a/src/agents/embedded-agent-runner/run/runtime-context-prompt.test.ts b/src/agents/embedded-agent-runner/run/runtime-context-prompt.test.ts
index f892ec432409..b80509f9839a 100644
--- a/src/agents/embedded-agent-runner/run/runtime-context-prompt.test.ts
+++ b/src/agents/embedded-agent-runner/run/runtime-context-prompt.test.ts
@@ -219,7 +219,9 @@ describe("runtime context prompt submission", () => {
         "OpenClaw runtime event.",
         "This context is runtime-generated, not user-authored. Keep internal details private.",
         "",
+        "<<<BEGIN_OPENCLAW_INTERNAL_CONTEXT>>>",
         "internal event",
+        "<<<END_OPENCLAW_INTERNAL_CONTEXT>>>",
       ].join("\n"),
     });
   });
@@ -242,7 +244,9 @@ describe("runtime context prompt submission", () => {
         "OpenClaw runtime event.",
         "This context is runtime-generated, not user-authored. Keep internal details private.",
         "",
+        "<<<BEGIN_OPENCLAW_INTERNAL_CONTEXT>>>",
         "internal event",
+        "<<<END_OPENCLAW_INTERNAL_CONTEXT>>>",
       ].join("\n"),
     });
   });
@@ -339,7 +343,9 @@ describe("runtime context prompt submission", () => {
         "OpenClaw runtime context for the immediately preceding user message.",
         "This context is runtime-generated, not user-authored. Keep internal details private.",
         "",
+        "<<<BEGIN_OPENCLAW_INTERNAL_CONTEXT>>>",
         "secret runtime context",
+        "<<<END_OPENCLAW_INTERNAL_CONTEXT>>>",
       ].join("\n"),
       display: false,
       details: { source: "openclaw-runtime-context" },
diff --git a/src/agents/embedded-agent-runner/run/runtime-context-prompt.ts b/src/agents/embedded-agent-runner/run/runtime-context-prompt.ts
index 76ba70319e80..57d00d9c04f6 100644
--- a/src/agents/embedded-agent-runner/run/runtime-context-prompt.ts
+++ b/src/agents/embedded-agent-runner/run/runtime-context-prompt.ts
@@ -3,6 +3,8 @@
  */
 import {
   extractInternalRuntimeContext,
+  INTERNAL_RUNTIME_CONTEXT_BEGIN,
+  INTERNAL_RUNTIME_CONTEXT_END,
   OPENCLAW_NEXT_TURN_RUNTIME_CONTEXT_HEADER,
   OPENCLAW_RUNTIME_CONTEXT_CUSTOM_TYPE,
   OPENCLAW_RUNTIME_CONTEXT_NOTICE,
@@ -153,13 +155,18 @@ function buildRuntimeContextMessageContent(params: {
   runtimeContext: string;
   kind: "next-turn" | "runtime-event";
 }): string {
+  // Wrap the runtime context body in delimited internal-context markers so
+  // stripInternalRuntimeContext can fully remove the block when it leaks
+  // into user-visible surfaces (e.g. Feishu streaming cards, #92589).
   return [
     params.kind === "runtime-event"
       ? OPENCLAW_RUNTIME_EVENT_HEADER
       : OPENCLAW_NEXT_TURN_RUNTIME_CONTEXT_HEADER,
     OPENCLAW_RUNTIME_CONTEXT_NOTICE,
     "",
+    INTERNAL_RUNTIME_CONTEXT_BEGIN,
     params.runtimeContext,
+    INTERNAL_RUNTIME_CONTEXT_END,
   ].join("\n");
 }