diff --git a/ui/src/components/config-form-scalar-integrity.browser.test.ts b/ui/src/components/config-form-scalar-integrity.browser.test.ts
index b6cb2d0d3d0d..c777014decfc 100644
--- a/ui/src/components/config-form-scalar-integrity.browser.test.ts
+++ b/ui/src/components/config-form-scalar-integrity.browser.test.ts
@@ -355,4 +355,35 @@ describe("config form scalar integrity", () => {
     expect(reset.disabled).toBe(true);
     expect(container.textContent).not.toContain("inherited");
   });
+
+  it("never reveals a server-redacted sentinel and keeps the input readonly", () => {
+    const container = document.createElement("div");
+
+    render(
+      renderTextInput({
+        schema: { type: "string" },
+        value: "__OPENCLAW_REDACTED__",
+        path: ["secret"],
+        hints: { secret: { sensitive: true } },
+        unsupported: new Set(),
+        disabled: false,
+        inputType: "text",
+        // Even with reveal forced on, the sentinel is not the stored value;
+        // showing it editable would let a stray edit overwrite the credential.
+        revealSensitive: true,
+        onPatch: vi.fn(),
+        onRemove: vi.fn(),
+      }),
+      container,
+    );
+
+    const input = expectElement(
+      container.querySelector<HTMLInputElement>("input"),
+      "sentinel secret input",
+    );
+    expect(input.value).not.toContain("__OPENCLAW_REDACTED__");
+    expect(input.readOnly).toBe(true);
+    const eye = container.querySelector<HTMLButtonElement>(".settings-secret__toggle");
+    expect(eye?.disabled ?? true).toBe(true);
+  });
 });
diff --git a/ui/src/components/config-form.node.shared.ts b/ui/src/components/config-form.node.shared.ts
index 7331a944a185..9b425f4336e8 100644
--- a/ui/src/components/config-form.node.shared.ts
+++ b/ui/src/components/config-form.node.shared.ts
@@ -4,8 +4,9 @@ import { html, nothing, type TemplateResult } from "lit";
 import { ref } from "lit/directives/ref.js";
 import type { ConfigUiHints } from "../api/types.ts";
 import { icons } from "../components/icons.ts";
-import "../components/tooltip.ts";
 import { t } from "../i18n/index.ts";
+import "../components/tooltip.ts";
+import { REDACTED_SENTINEL } from "../lib/config-form-utils.ts";
 import { formatUnknownText } from "../lib/format.ts";
 import { isSupportedConfigValueValid } from "./config-form.constraints.ts";
 import type { ConfigSearchCriteria } from "./config-form.search.ts";
@@ -64,6 +65,7 @@ type SensitiveRenderState = {
   isRedacted: boolean;
   isRevealed: boolean;
   canReveal: boolean;
+  sentinelRedacted: boolean;
 };
 
 export function isAnySchema(schema: JsonSchema): boolean {
@@ -130,14 +132,20 @@ export function getSensitiveRenderState(params: {
   isSensitivePathRevealed?: (path: Array<string | number>) => boolean;
 }): SensitiveRenderState {
   const isSensitive = hasSensitiveConfigData(params.value, params.path, params.hints);
+  // The server never sends plaintext secrets: a stored secret arrives as the
+  // redaction sentinel. Revealing it would display the sentinel as an editable
+  // value; any edit then overwrites the real credential with mangled text.
+  const sentinel = params.value === REDACTED_SENTINEL;
   const isRevealed =
     isSensitive &&
+    !sentinel &&
     (params.revealSensitive || (params.isSensitivePathRevealed?.(params.path) ?? false));
   return {
     isSensitive,
     isRedacted: isSensitive && !isRevealed,
     isRevealed,
-    canReveal: isSensitive,
+    canReveal: isSensitive && !sentinel,
+    sentinelRedacted: sentinel,
   };
 }
 
@@ -155,7 +163,9 @@ export function renderSensitiveToggleButton(params: {
     ? state.isRevealed
       ? t("configForm.hideValue")
       : t("configForm.revealValue")
-    : t("configForm.disableStreamToReveal");
+    : state.sentinelRedacted
+      ? t("configForm.storedSecretNotRevealable")
+      : t("configForm.disableStreamToReveal");
   return html`
     <openclaw-tooltip .content=${label}>
       <button
diff --git a/ui/src/i18n/locales/en.ts b/ui/src/i18n/locales/en.ts
index 069d4f66d489..451ca70ad67b 100644
--- a/ui/src/i18n/locales/en.ts
+++ b/ui/src/i18n/locales/en.ts
@@ -1244,6 +1244,8 @@ export const en: TranslationMap = {
     hideValue: "Hide value",
     revealValue: "Reveal value",
     disableStreamToReveal: "Disable stream mode to reveal value",
+    storedSecretNotRevealable:
+      "Stored secrets are never sent to the browser; enter a new value to replace it",
     unsupportedType: "Unsupported type: {type}. Use Raw mode.",
     structuredSecretRaw: "Structured value (SecretRef) - use Raw mode to edit",
     structuredSecretFile: "Structured value (SecretRef) - edit the config file directly",
diff --git a/ui/src/lib/config-form-utils.ts b/ui/src/lib/config-form-utils.ts
index c576026094d8..f97cf72b6cf7 100644
--- a/ui/src/lib/config-form-utils.ts
+++ b/ui/src/lib/config-form-utils.ts
@@ -9,7 +9,7 @@ export function serializeConfigForm(form: Record<string, unknown>): string {
   return `${JSON.stringify(form, null, 2).trimEnd()}\n`;
 }
 
-const REDACTED_SENTINEL = "__OPENCLAW_REDACTED__";
+export const REDACTED_SENTINEL = "__OPENCLAW_REDACTED__";
 type SanitizeResult = { omitted: true } | { omitted: false; value: unknown };
 
 const OMIT_VALUE: SanitizeResult = { omitted: true };