diff --git a/CHANGELOG.md b/CHANGELOG.md
index 62f1f6774e6..b5167cb19d8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -25,6 +25,9 @@ Docs: https://docs.openclaw.ai
 
 ### Fixes
 
+- Agents/replies: forward sanitized underlying agent failure details on external
+  channels instead of replacing unknown failures with a generic retry message.
+  Thanks @steipete.
 - Agents/TTS: preserve `[[audio_as_voice]]` directives on trusted text
   tool-result `MEDIA:` payloads so generated audio still delivers as a voice
   note. (#46535) Thanks @azade-c.
diff --git a/src/auto-reply/reply/agent-runner-execution.test.ts b/src/auto-reply/reply/agent-runner-execution.test.ts
index 8ef3fa8bdf9..b25fca49f72 100644
--- a/src/auto-reply/reply/agent-runner-execution.test.ts
+++ b/src/auto-reply/reply/agent-runner-execution.test.ts
@@ -1662,7 +1662,9 @@ describe("runAgentTurnWithFallback", () => {
 
     expect(result.kind).toBe("final");
     if (result.kind === "final") {
-      expect(result.payload.text).toContain("Something went wrong while processing your request");
+      expect(result.payload.text).toContain("Agent failed before reply");
+      expect(result.payload.text).toContain("All models failed");
+      expect(result.payload.text).toContain("402 (billing)");
       expect(result.payload.text).not.toContain("Rate-limited");
     }
   });
@@ -1877,7 +1879,7 @@ describe("runAgentTurnWithFallback", () => {
     expect(failMock).not.toHaveBeenCalled();
   });
 
-  it("returns a friendly generic error on external chat channels", async () => {
+  it("forwards sanitized generic errors on external chat channels", async () => {
     state.runEmbeddedPiAgentMock.mockRejectedValueOnce(
       new Error("INVALID_ARGUMENT: some other failure"),
     );
@@ -1910,7 +1912,47 @@ describe("runAgentTurnWithFallback", () => {
     expect(result.kind).toBe("final");
     if (result.kind === "final") {
       expect(result.payload.text).toBe(
-        "⚠️ Something went wrong while processing your request. Please try again, or use /new to start a fresh session.",
+        "⚠️ Agent failed before reply: INVALID_ARGUMENT: some other failure. Please try again, or use /new to start a fresh session.",
+      );
+    }
+  });
+
+  it("formats raw Codex API payloads before forwarding external errors", async () => {
+    state.runEmbeddedPiAgentMock.mockRejectedValueOnce(
+      new Error(
+        'Codex error: {"type":"error","error":{"type":"server_error","message":"Something exploded"},"sequence_number":2}',
+      ),
+    );
+
+    const runAgentTurnWithFallback = await getRunAgentTurnWithFallback();
+    const result = await runAgentTurnWithFallback({
+      commandBody: "hello",
+      followupRun: createFollowupRun(),
+      sessionCtx: {
+        Provider: "whatsapp",
+        MessageSid: "msg",
+      } as unknown as TemplateContext,
+      opts: {},
+      typingSignals: createMockTypingSignaler(),
+      blockReplyPipeline: null,
+      blockStreamingEnabled: false,
+      resolvedBlockStreamingBreak: "message_end",
+      applyReplyToMode: (payload) => payload,
+      shouldEmitToolResult: () => true,
+      shouldEmitToolOutput: () => false,
+      pendingToolTasks: new Set(),
+      resetSessionAfterCompactionFailure: async () => false,
+      resetSessionAfterRoleOrderingConflict: async () => false,
+      isHeartbeat: false,
+      sessionKey: "main",
+      getActiveSessionEntry: () => undefined,
+      resolvedVerboseLevel: "off",
+    });
+
+    expect(result.kind).toBe("final");
+    if (result.kind === "final") {
+      expect(result.payload.text).toBe(
+        "⚠️ Agent failed before reply: LLM error server_error: Something exploded. Please try again, or use /new to start a fresh session.",
       );
     }
   });
diff --git a/src/auto-reply/reply/agent-runner-execution.ts b/src/auto-reply/reply/agent-runner-execution.ts
index f0e7dc3ecea..3ec304e4c4b 100644
--- a/src/auto-reply/reply/agent-runner-execution.ts
+++ b/src/auto-reply/reply/agent-runner-execution.ts
@@ -352,6 +352,7 @@ function collapseRepeatedFailureDetail(message: string): string {
 }
 
 const SAFE_MISSING_API_KEY_PROVIDERS = new Set(["anthropic", "google", "openai", "openai-codex"]);
+const EXTERNAL_RUN_FAILURE_DETAIL_MAX_CHARS = 900;
 
 function buildMissingApiKeyFailureText(message: string): string | null {
   const normalizedMessage = collapseRepeatedFailureDetail(message);
@@ -369,6 +370,22 @@ function buildMissingApiKeyFailureText(message: string): string | null {
   return "⚠️ Missing API key for the selected provider on the gateway. Configure provider auth, then try again.";
 }
 
+function formatForwardedExternalRunFailureText(message: string): string {
+  const sanitized = sanitizeUserFacingText(message, { errorContext: true })
+    .trim()
+    .replace(/^⚠️\s*/u, "")
+    .replace(/\s+/gu, " ");
+  if (!sanitized) {
+    return "⚠️ Something went wrong while processing your request. Please try again, or use /new to start a fresh session.";
+  }
+  const detail =
+    sanitized.length > EXTERNAL_RUN_FAILURE_DETAIL_MAX_CHARS
+      ? `${sanitized.slice(0, EXTERNAL_RUN_FAILURE_DETAIL_MAX_CHARS - 1).trimEnd()}…`
+      : sanitized;
+  const suffix = /[.!?]$/u.test(detail) ? "" : ".";
+  return `⚠️ Agent failed before reply: ${detail}${suffix} Please try again, or use /new to start a fresh session.`;
+}
+
 function buildExternalRunFailureText(message: string): string {
   const normalizedMessage = collapseRepeatedFailureDetail(message);
   if (isToolResultTurnMismatchError(normalizedMessage)) {
@@ -386,7 +403,7 @@ function buildExternalRunFailureText(message: string): string {
     }
     return `⚠️ Model login failed on the gateway${oauthRefreshFailure.provider ? ` for ${oauthRefreshFailure.provider}` : ""}. Please try again. If this keeps happening, re-auth with \`${loginCommand}\`.`;
   }
-  return "⚠️ Something went wrong while processing your request. Please try again, or use /new to start a fresh session.";
+  return formatForwardedExternalRunFailureText(normalizedMessage);
 }
 
 function shouldApplyOpenAIGptChatGuard(params: { provider?: string; model?: string }): boolean {