diff --git a/packages/apollo-react/src/canvas/components/Guardrails/README.md b/packages/apollo-react/src/canvas/components/Guardrails/README.md
index 9f021549e..6b7a68717 100644
--- a/packages/apollo-react/src/canvas/components/Guardrails/README.md
+++ b/packages/apollo-react/src/canvas/components/Guardrails/README.md
@@ -954,6 +954,11 @@ const [action, setAction] = useState<GuardrailAction>({
   action outside the list never blanks the select. Both builders forward it, and start a new
   guardrail on the first allowed type when log is not among them. `GuardrailBuilder`'s takes no
   `filter`, which it has no field picker for.
+- **`hideLogSeverity` drops the severity select** for a host whose log action has no severity
+  (Flow's Guardrail node, where log is relabelled Fail). The type select keeps its column, so
+  it does not move when the user switches to block. `severityLevel` is left as it is: a new
+  guardrail saves `'Info'`, an edited one its stored value, and the host overwrites it on save
+  if it needs another. `GuardrailBuilder` forwards it.
 - **Asset recipients round-trip.** Types 4 and 6 display as their static siblings (3 and 5) in
   the type select, so a value written by a host asset editor never blanks the selection.
 - **Recipient types outside 1-6 pass through.** Agents' argument (7, 8) and
diff --git a/packages/apollo-react/src/canvas/components/Guardrails/components/guardrail-action-section.stories.tsx b/packages/apollo-react/src/canvas/components/Guardrails/components/guardrail-action-section.stories.tsx
index 639473ef0..660eeda95 100644
--- a/packages/apollo-react/src/canvas/components/Guardrails/components/guardrail-action-section.stories.tsx
+++ b/packages/apollo-react/src/canvas/components/Guardrails/components/guardrail-action-section.stories.tsx
@@ -183,6 +183,14 @@ export const AllowedActionTypes: Story = {
   render: () => <ActionSectionHost initial={logAction} allowedActionTypes={['log', 'block']} />,
 };
 
+/** hideLogSeverity drops the severity select; the action keeps its severityLevel. */
+export const LogWithoutSeverity: Story = {
+  args: { action: logAction, onActionChange: () => {} },
+  render: () => (
+    <ActionSectionHost initial={logAction} allowedActionTypes={['log', 'block']} hideLogSeverity />
+  ),
+};
+
 /** Filter appears only with showFilter, and its field picker is host content. */
 export const FilterWithHostFieldPicker: Story = {
   args: { action: { $actionType: 'filter', fields: [] }, onActionChange: () => {} },
diff --git a/packages/apollo-react/src/canvas/components/Guardrails/components/guardrail-action-section.test.tsx b/packages/apollo-react/src/canvas/components/Guardrails/components/guardrail-action-section.test.tsx
index 242a2ca43..faca29305 100644
--- a/packages/apollo-react/src/canvas/components/Guardrails/components/guardrail-action-section.test.tsx
+++ b/packages/apollo-react/src/canvas/components/Guardrails/components/guardrail-action-section.test.tsx
@@ -117,6 +117,52 @@ describe('GuardrailActionSection', () => {
     expect(onActionChange).toHaveBeenCalledWith({ $actionType: 'log', severityLevel: 'Warning' });
   });
 
+  describe('hideLogSeverity', () => {
+    it('shows the severity select by default', () => {
+      render(<GuardrailActionSection action={logAction} onActionChange={vi.fn()} />);
+
+      expect(screen.getByRole('combobox', { name: /severity level/i })).toBeInTheDocument();
+    });
+
+    it('hides the severity select for log actions', () => {
+      render(
+        <GuardrailActionSection action={logAction} onActionChange={vi.fn()} hideLogSeverity />
+      );
+
+      expect(screen.getByRole('combobox', { name: /action type/i })).toHaveTextContent('Log');
+      expect(screen.queryByRole('combobox', { name: /severity level/i })).not.toBeInTheDocument();
+      expect(screen.queryByText('Severity level')).not.toBeInTheDocument();
+    });
+
+    it('still emits a severity level when switching to log', async () => {
+      const onActionChange = vi.fn();
+      render(
+        <GuardrailActionSection
+          action={{ $actionType: 'block', reason: 'no PII' }}
+          onActionChange={onActionChange}
+          hideLogSeverity
+        />
+      );
+
+      fireEvent.click(screen.getByRole('combobox', { name: /action type/i }));
+      fireEvent.click(await screen.findByRole('option', { name: 'Log' }));
+
+      expect(onActionChange).toHaveBeenCalledWith({ $actionType: 'log', severityLevel: 'Info' });
+    });
+
+    it('leaves the other action types alone', () => {
+      render(
+        <GuardrailActionSection
+          action={{ $actionType: 'block', reason: '' }}
+          onActionChange={vi.fn()}
+          hideLogSeverity
+        />
+      );
+
+      expect(screen.getByLabelText(/blocking reason/i)).toBeInTheDocument();
+    });
+  });
+
   it('renders the blocking reason input with its error for block actions', () => {
     const onActionChange = vi.fn();
     render(
diff --git a/packages/apollo-react/src/canvas/components/Guardrails/components/guardrail-action-section.tsx b/packages/apollo-react/src/canvas/components/Guardrails/components/guardrail-action-section.tsx
index 030b616e5..f977213bf 100644
--- a/packages/apollo-react/src/canvas/components/Guardrails/components/guardrail-action-section.tsx
+++ b/packages/apollo-react/src/canvas/components/Guardrails/components/guardrail-action-section.tsx
@@ -39,6 +39,11 @@ export interface GuardrailActionSectionProps {
    * action outside the list never blanks the select.
    */
   allowedActionTypes?: readonly GuardrailActionType[];
+  /**
+   * Hide the severity level select for a log action, for a host whose log action has no
+   * severity. The action's `severityLevel` is left as it is, for the host to set.
+   */
+  hideLogSeverity?: boolean;
   /** Content rendered as the second grid column when $actionType === 'filter' */
   filterContent?: ReactNode;
   /** Validation messages; each renders as soon as it is present. */
@@ -72,6 +77,7 @@ export function GuardrailActionSection({
   onActionChange,
   showFilter = false,
   allowedActionTypes,
+  hideLogSeverity = false,
   filterContent,
   errors,
   recipientTypeDisabled,
@@ -150,7 +156,7 @@ export function GuardrailActionSection({
       <div className="grid grid-cols-1 @sm:grid-cols-2 gap-3 items-start">
         {actionTypeSelect}
 
-        {action.$actionType === 'log' && (
+        {action.$actionType === 'log' && !hideLogSeverity && (
           <FormField>
             <Label htmlFor={`${uid}-severity-level`}>
               {labels.severityLabel}
diff --git a/packages/apollo-react/src/canvas/components/Guardrails/guardrail-builder.stories.tsx b/packages/apollo-react/src/canvas/components/Guardrails/guardrail-builder.stories.tsx
index 763dfdae9..000c155c9 100644
--- a/packages/apollo-react/src/canvas/components/Guardrails/guardrail-builder.stories.tsx
+++ b/packages/apollo-react/src/canvas/components/Guardrails/guardrail-builder.stories.tsx
@@ -381,6 +381,20 @@ export const FooterEvalsToggle: Story = {
   args: { ...AddInline.args, evalsTogglePlacement: 'footer' },
 };
 
+/**
+ * A host whose log action has no severity: hideLogSeverity drops the severity select, here with
+ * log relabelled Fail and block as the only other action.
+ */
+export const LogWithoutSeverity: Story = {
+  args: {
+    ...AddInline.args,
+    scope: 'Llm',
+    allowedActionTypes: ['log', 'block'],
+    hideLogSeverity: true,
+    labels: { actionLogLabel: 'Fail' },
+  },
+};
+
 /** Chrome strings resolved from the canvas lingui catalog (Japanese). */
 export const Localized: Story = {
   args: { ...AddInline.args },
diff --git a/packages/apollo-react/src/canvas/components/Guardrails/guardrail-builder.test.tsx b/packages/apollo-react/src/canvas/components/Guardrails/guardrail-builder.test.tsx
index 9e9d9ca3b..28b1759d7 100644
--- a/packages/apollo-react/src/canvas/components/Guardrails/guardrail-builder.test.tsx
+++ b/packages/apollo-react/src/canvas/components/Guardrails/guardrail-builder.test.tsx
@@ -1648,6 +1648,75 @@ describe('GuardrailBuilder', () => {
       expect(screen.getByRole('combobox', { name: /action type/i })).toHaveTextContent('Log');
     });
 
+    it('shows the log severity select by default', () => {
+      render(
+        <GuardrailBuilder
+          open
+          inline
+          hideHeader
+          definition={makeDef()}
+          scope="Llm"
+          defaultName="PII 1"
+          onSave={vi.fn()}
+          onCancel={vi.fn()}
+        />
+      );
+
+      expect(screen.getByRole('combobox', { name: /severity level/i })).toBeInTheDocument();
+    });
+
+    it('hides the log severity select with hideLogSeverity and saves the default severity', () => {
+      const onSave = vi.fn();
+      render(
+        <GuardrailBuilder
+          open
+          inline
+          hideHeader
+          definition={makeDef()}
+          scope="Llm"
+          defaultName="PII 1"
+          hideLogSeverity
+          onSave={onSave}
+          onCancel={vi.fn()}
+        />
+      );
+
+      expect(screen.getByRole('combobox', { name: /action type/i })).toHaveTextContent('Log');
+      expect(screen.queryByRole('combobox', { name: /severity level/i })).not.toBeInTheDocument();
+
+      fireEvent.click(screen.getByRole('button', { name: 'Save' }));
+      expect(onSave).toHaveBeenCalledWith(
+        expect.objectContaining({ action: { $actionType: 'log', severityLevel: 'Info' } })
+      );
+    });
+
+    it('saves an edited guardrail with its stored severity under hideLogSeverity', () => {
+      const onSave = vi.fn();
+      render(
+        <GuardrailBuilder
+          open
+          inline
+          hideHeader
+          definition={makeDef()}
+          scope="Llm"
+          guardrail={makeGuardrail({
+            selector: { scopes: ['Llm'] },
+            action: { $actionType: 'log', severityLevel: 'Error' },
+          })}
+          hideLogSeverity
+          onSave={onSave}
+          onCancel={vi.fn()}
+        />
+      );
+
+      expect(screen.queryByRole('combobox', { name: /severity level/i })).not.toBeInTheDocument();
+
+      fireEvent.click(screen.getByRole('button', { name: 'Save' }));
+      expect(onSave).toHaveBeenCalledWith(
+        expect.objectContaining({ action: { $actionType: 'log', severityLevel: 'Error' } })
+      );
+    });
+
     it('saves a recipient type it does not model unchanged', () => {
       const onSave = vi.fn();
       // Agents' ArgumentEmail, passed in with a cast as the host does.
diff --git a/packages/apollo-react/src/canvas/components/Guardrails/guardrail-builder.tsx b/packages/apollo-react/src/canvas/components/Guardrails/guardrail-builder.tsx
index b71beda2c..c6dc58b62 100644
--- a/packages/apollo-react/src/canvas/components/Guardrails/guardrail-builder.tsx
+++ b/packages/apollo-react/src/canvas/components/Guardrails/guardrail-builder.tsx
@@ -130,6 +130,12 @@ export interface GuardrailBuilderProps {
    * builder has no field picker to edit it (`CustomGuardrailBuilder` does).
    */
   allowedActionTypes?: ReadonlyArray<Exclude<GuardrailAction['$actionType'], 'filter'>>;
+  /**
+   * Hide the severity level select for a log action, for a host whose log action has no
+   * severity. A new guardrail still saves the default `'Info'` and an edited one its stored
+   * `severityLevel`; the host overwrites it on save if it needs another.
+   */
+  hideLogSeverity?: boolean;
   renderRecipientSearch?: (ctx: GuardrailRecipientSearchContext) => ReactNode;
   /**
    * Replace the editor for static/asset recipients (types 3/4/5/6). Return `undefined` to
@@ -200,6 +206,7 @@ export function GuardrailBuilder({
   policyName,
   evalsTogglePlacement = 'form',
   allowedActionTypes,
+  hideLogSeverity,
   renderRecipientSearch,
   renderStaticRecipient,
   renderAppPicker,
@@ -556,6 +563,7 @@ export function GuardrailBuilder({
           action={formData.action}
           onActionChange={(action) => updateField('action', action)}
           allowedActionTypes={allowedActionTypes}
+          hideLogSeverity={hideLogSeverity}
           errors={{
             blockReason: displayErrors.blockReason,
             filterFields: displayErrors.filterFields,