diff --git a/src/gateway/chat-display-projection.ts b/src/gateway/chat-display-projection.ts
index 0be281e5cb97..1328d43a8564 100644
--- a/src/gateway/chat-display-projection.ts
+++ b/src/gateway/chat-display-projection.ts
@@ -580,7 +580,7 @@ function extractAssistantTextForSilentCheck(message: unknown): string | undefine
       return undefined;
     }
     const typed = block as { type?: unknown; text?: unknown };
-    if ((typed.type !== "text" && typed.type !== "output_text") || typeof typed.text !== "string") {
+    if (!isAssistantTextContentType(typed.type) || typeof typed.text !== "string") {
       return undefined;
     }
     texts.push(typed.text);
@@ -588,6 +588,10 @@ function extractAssistantTextForSilentCheck(message: unknown): string | undefine
   return texts.length > 0 ? texts.join("\n") : undefined;
 }
 
+function isAssistantTextContentType(type: unknown): boolean {
+  return type === "text" || type === "input_text" || type === "output_text";
+}
+
 function hasAssistantNonTextContent(message: unknown): boolean {
   if (!message || typeof message !== "object") {
     return false;
@@ -600,8 +604,7 @@ function hasAssistantNonTextContent(message: unknown): boolean {
     (block) =>
       block &&
       typeof block === "object" &&
-      (block as { type?: unknown }).type !== "text" &&
-      (block as { type?: unknown }).type !== "output_text",
+      !isAssistantTextContentType((block as { type?: unknown }).type),
   );
 }
 
@@ -623,7 +626,11 @@ function hasAssistantMixedToolVisibleText(message: unknown): boolean {
     if (isToolHistoryBlockType(entry.type)) {
       hasToolHistoryBlock = true;
     }
-    if (entry.type === "text" && typeof entry.text === "string" && entry.text.trim()) {
+    if (
+      isAssistantTextContentType(entry.type) &&
+      typeof entry.text === "string" &&
+      entry.text.trim()
+    ) {
       hasText = true;
     }
   }
@@ -1648,7 +1655,7 @@ function projectEmptyAssistantErrorMessages(
         }
         const type = (block as { type?: unknown }).type;
         return (
-          type !== "text" &&
+          !isAssistantTextContentType(type) &&
           type !== "thinking" &&
           type !== "reasoning" &&
           type !== "redacted_thinking"
@@ -1669,7 +1676,7 @@ function projectEmptyAssistantErrorMessages(
           continue;
         }
         const entry = block as { type?: unknown; text?: unknown };
-        if (entry.type === "text" && typeof entry.text === "string") {
+        if (isAssistantTextContentType(entry.type) && typeof entry.text === "string") {
           visibleTexts.push(entry.text);
         }
       }
diff --git a/src/gateway/chat-sanitize.test.ts b/src/gateway/chat-sanitize.test.ts
index 6de855579b3e..49d9c14dd558 100644
--- a/src/gateway/chat-sanitize.test.ts
+++ b/src/gateway/chat-sanitize.test.ts
@@ -44,6 +44,20 @@ describe("stripEnvelopeFromMessage", () => {
     expect(assistant.content?.[0]?.text).toBe("Assistant body");
   });
 
+  test("strips internal metadata from assistant input_text blocks", () => {
+    const assistant = stripEnvelopeFromMessage({
+      role: "assistant",
+      content: [
+        {
+          type: "input_text",
+          text: 'Conversation info (untrusted metadata):\n```json\n{"message_id":"123"}\n```\n\nAssistant body',
+        },
+      ],
+    }) as { content?: Array<{ text?: string }> };
+
+    expect(assistant.content?.[0]?.text).toBe("Assistant body");
+  });
+
   test("does not strip inline message_id text that is part of a line", () => {
     const input = {
       role: "user",
diff --git a/src/gateway/chat-sanitize.ts b/src/gateway/chat-sanitize.ts
index 26905ba485af..628dda8b387d 100644
--- a/src/gateway/chat-sanitize.ts
+++ b/src/gateway/chat-sanitize.ts
@@ -59,7 +59,7 @@ function stripEnvelopeFromContentWithRole(
     const isRoleTextBlock =
       entry.type === "text" ||
       (role === "user" && entry.type === "input_text") ||
-      (role === "assistant" && entry.type === "output_text");
+      (role === "assistant" && (entry.type === "input_text" || entry.type === "output_text"));
     if (!isRoleTextBlock || typeof entry.text !== "string") {
       return item;
     }
diff --git a/src/gateway/server-methods/server-methods.test.ts b/src/gateway/server-methods/server-methods.test.ts
index 44ba7792da11..f9f51c18ac3c 100644
--- a/src/gateway/server-methods/server-methods.test.ts
+++ b/src/gateway/server-methods/server-methods.test.ts
@@ -941,6 +941,43 @@ describe("projectRecentChatDisplayMessages", () => {
     ]);
   });
 
+  it.each([
+    ["output_text", ""],
+    ["output_text", "NO_REPLY"],
+    ["input_text", ""],
+    ["input_text", "NO_REPLY"],
+  ])("projects hidden %s assistant errors %j as a generic safe failure", (type, text) => {
+    const result = projectRecentChatDisplayMessages([
+      {
+        role: "assistant",
+        content: [{ type, text }],
+        stopReason: "error",
+        errorMessage: "Connection error.",
+        timestamp: 1,
+      },
+    ]);
+
+    expect(result[0]?.content).toEqual([
+      { type: "text", text: "The agent run failed before producing a reply." },
+    ]);
+  });
+
+  it("preserves visible output_text from a failed assistant turn", () => {
+    const result = projectRecentChatDisplayMessages([
+      {
+        role: "assistant",
+        content: [{ type: "output_text", text: "A partial reply before the run failed." }],
+        stopReason: "error",
+        errorMessage: "Connection error.",
+        timestamp: 1,
+      },
+    ]);
+
+    expect(result[0]?.content).toEqual([
+      { type: "output_text", text: "A partial reply before the run failed." },
+    ]);
+  });
+
   it("projects thinking-only assistant errors as a generic safe failure", () => {
     const result = projectRecentChatDisplayMessages([
       {
diff --git a/src/gateway/server.chat.gateway-server-chat.test.ts b/src/gateway/server.chat.gateway-server-chat.test.ts
index 40b308a120e8..4fd028286a2f 100644
--- a/src/gateway/server.chat.gateway-server-chat.test.ts
+++ b/src/gateway/server.chat.gateway-server-chat.test.ts
@@ -714,9 +714,22 @@ describe("gateway server chat", () => {
         content: [{ type: "output_text", text: "visible response" }],
         timestamp: 2,
       },
+      {
+        role: "assistant",
+        content: [{ type: "input_text", text: "NO_REPLY" }],
+        timestamp: 3,
+      },
+      {
+        role: "assistant",
+        content: [{ type: "input_text", text: "visible assistant input" }],
+        timestamp: 4,
+      },
     ]);
 
-    expect(collectHistoryTextValues(historyMessages)).toEqual(["visible response"]);
+    expect(collectHistoryTextValues(historyMessages)).toEqual([
+      "visible response",
+      "visible assistant input",
+    ]);
   });
 
   test("chat.history mirrors current-session message tool sends before NO_REPLY", async () => {
diff --git a/src/shared/chat-message-content.test.ts b/src/shared/chat-message-content.test.ts
index f022c5f0ef91..479cecca9aac 100644
--- a/src/shared/chat-message-content.test.ts
+++ b/src/shared/chat-message-content.test.ts
@@ -147,6 +147,15 @@ describe("extractAssistantVisibleText", () => {
     ).toBe("Persisted assistant answer");
   });
 
+  it("extracts persisted Responses assistant input_text blocks", () => {
+    expect(
+      extractAssistantVisibleText({
+        role: "assistant",
+        content: [{ type: "input_text", text: "Persisted assistant input" }],
+      }),
+    ).toBe("Persisted assistant input");
+  });
+
   it("does not mix unphased legacy text into final_answer output", () => {
     expect(
       extractAssistantVisibleText({
diff --git a/src/shared/chat-message-content.ts b/src/shared/chat-message-content.ts
index 8fb79c556f4d..1d610e8e8fb9 100644
--- a/src/shared/chat-message-content.ts
+++ b/src/shared/chat-message-content.ts
@@ -24,7 +24,7 @@ export function extractFirstTextBlock(message: unknown): string | undefined {
 export type AssistantPhase = "commentary" | "final_answer";
 
 function isAssistantTextContentBlockType(value: unknown): boolean {
-  return value === "text" || value === "output_text";
+  return value === "text" || value === "input_text" || value === "output_text";
 }
 
 /** Narrows unknown phase metadata to assistant text phases that affect visibility. */
diff --git a/ui/src/ui/chat/message-extract.test.ts b/ui/src/ui/chat/message-extract.test.ts
index 4d84c0cc38c8..3615968b3a68 100644
--- a/ui/src/ui/chat/message-extract.test.ts
+++ b/ui/src/ui/chat/message-extract.test.ts
@@ -59,7 +59,7 @@ describe("extractTextCached", () => {
     ).toBe("Persisted assistant answer");
   });
 
-  it("ignores persisted Responses text blocks from the wrong role", () => {
+  it("accepts assistant Responses input blocks but ignores user output blocks", () => {
     expect(
       extractText({
         role: "user",
@@ -71,7 +71,7 @@ describe("extractTextCached", () => {
         role: "assistant",
         content: [{ type: "input_text", text: "User-only block" }],
       }),
-    ).toBeNull();
+    ).toBe("User-only block");
   });
 
   it("prefers final_answer assistant text over commentary text", () => {
diff --git a/ui/src/ui/chat/message-extract.ts b/ui/src/ui/chat/message-extract.ts
index c7fd961829f6..cef618ea84d8 100644
--- a/ui/src/ui/chat/message-extract.ts
+++ b/ui/src/ui/chat/message-extract.ts
@@ -13,7 +13,7 @@ function isTextContentBlockType(value: unknown, role: string): boolean {
   return (
     value === "text" ||
     (role === "user" && value === "input_text") ||
-    (role === "assistant" && value === "output_text")
+    (role === "assistant" && (value === "input_text" || value === "output_text"))
   );
 }
 
diff --git a/ui/src/ui/chat/message-normalizer.test.ts b/ui/src/ui/chat/message-normalizer.test.ts
index 40324224d822..be2e841a9f63 100644
--- a/ui/src/ui/chat/message-normalizer.test.ts
+++ b/ui/src/ui/chat/message-normalizer.test.ts
@@ -111,7 +111,7 @@ describe("message-normalizer", () => {
       expect(assistant.content).toEqual([{ type: "text", text: "Persisted assistant answer" }]);
     });
 
-    it("does not reinterpret persisted Responses text blocks from the wrong role", () => {
+    it("accepts assistant Responses input blocks but rejects user output blocks", () => {
       const user = normalizeMessage({
         role: "user",
         content: [{ type: "output_text", text: "Assistant-only block" }],
@@ -122,7 +122,7 @@ describe("message-normalizer", () => {
       });
 
       expect(user.content).not.toContainEqual({ type: "text", text: "Assistant-only block" });
-      expect(assistant.content).not.toContainEqual({ type: "text", text: "User-only block" });
+      expect(assistant.content).toContainEqual({ type: "text", text: "User-only block" });
     });
 
     it("normalizes structured base64 audio content blocks as renderable attachments", () => {
diff --git a/ui/src/ui/chat/message-normalizer.ts b/ui/src/ui/chat/message-normalizer.ts
index 65f65b161ad9..a19e73150705 100644
--- a/ui/src/ui/chat/message-normalizer.ts
+++ b/ui/src/ui/chat/message-normalizer.ts
@@ -23,7 +23,7 @@ function isTextContentBlock(
     typeof item.text === "string" &&
     (item.type === "text" ||
       (role === "user" && item.type === "input_text") ||
-      (role === "assistant" && item.type === "output_text"))
+      (role === "assistant" && (item.type === "input_text" || item.type === "output_text")))
   );
 }