diff --git a/packages/cli/src/ui/components/InputPrompt.test.tsx b/packages/cli/src/ui/components/InputPrompt.test.tsx
index e1d68125..1a100c36 100644
--- a/packages/cli/src/ui/components/InputPrompt.test.tsx
+++ b/packages/cli/src/ui/components/InputPrompt.test.tsx
@@ -9,7 +9,7 @@ import { InputPrompt, InputPromptProps } from './InputPrompt.js';
 import type { TextBuffer } from './shared/text-buffer.js';
 import { Config } from '@google/gemini-cli-core';
 import { CommandContext, SlashCommand } from '../commands/types.js';
-import { vi } from 'vitest';
+import { describe, it, expect, beforeEach, vi } from 'vitest';
 import { useShellHistory } from '../hooks/useShellHistory.js';
 import { useCompletion } from '../hooks/useCompletion.js';
 import { useInputHistory } from '../hooks/useInputHistory.js';
@@ -341,7 +341,7 @@ describe('InputPrompt', () => {
     });
   });
 
-  it('should complete a partial parent command and add a space', async () => {
+  it('should complete a partial parent command', async () => {
     // SCENARIO: /mem -> Tab
     mockedUseCompletion.mockReturnValue({
       ...mockCompletion,
@@ -357,12 +357,12 @@ describe('InputPrompt', () => {
     stdin.write('\t'); // Press Tab
     await wait();
 
-    expect(props.buffer.setText).toHaveBeenCalledWith('/memory ');
+    expect(props.buffer.setText).toHaveBeenCalledWith('/memory');
     unmount();
   });
 
-  it('should append a sub-command when the parent command is already complete with a space', async () => {
-    // SCENARIO: /memory  -> Tab (to accept 'add')
+  it('should append a sub-command when the parent command is already complete', async () => {
+    // SCENARIO: /memory -> Tab (to accept 'add')
     mockedUseCompletion.mockReturnValue({
       ...mockCompletion,
       showSuggestions: true,
@@ -380,13 +380,12 @@ describe('InputPrompt', () => {
     stdin.write('\t'); // Press Tab
     await wait();
 
-    expect(props.buffer.setText).toHaveBeenCalledWith('/memory add ');
+    expect(props.buffer.setText).toHaveBeenCalledWith('/memory add');
     unmount();
   });
 
   it('should handle the "backspace" edge case correctly', async () => {
-    // SCENARIO: /memory  -> Backspace -> /memory -> Tab (to accept 'show')
-    // This is the critical bug we fixed.
+    // SCENARIO: /memory -> Backspace -> /memory -> Tab (to accept 'show')
     mockedUseCompletion.mockReturnValue({
       ...mockCompletion,
       showSuggestions: true,
@@ -405,8 +404,8 @@ describe('InputPrompt', () => {
     stdin.write('\t'); // Press Tab
     await wait();
 
-    // It should NOT become '/show '. It should correctly become '/memory show '.
-    expect(props.buffer.setText).toHaveBeenCalledWith('/memory show ');
+    // It should NOT become '/show'. It should correctly become '/memory show'.
+    expect(props.buffer.setText).toHaveBeenCalledWith('/memory show');
     unmount();
   });
 
@@ -426,7 +425,7 @@ describe('InputPrompt', () => {
     stdin.write('\t'); // Press Tab
     await wait();
 
-    expect(props.buffer.setText).toHaveBeenCalledWith('/chat resume fix-foo ');
+    expect(props.buffer.setText).toHaveBeenCalledWith('/chat resume fix-foo');
     unmount();
   });
 
@@ -446,7 +445,7 @@ describe('InputPrompt', () => {
     await wait();
 
     // The app should autocomplete the text, NOT submit.
-    expect(props.buffer.setText).toHaveBeenCalledWith('/memory ');
+    expect(props.buffer.setText).toHaveBeenCalledWith('/memory');
 
     expect(props.onSubmit).not.toHaveBeenCalled();
     unmount();
@@ -471,10 +470,10 @@ describe('InputPrompt', () => {
     const { stdin, unmount } = render(<InputPrompt {...props} />);
     await wait();
 
-    stdin.write('\t'); // Press Tab
+    stdin.write('\t'); // Press Tab for autocomplete
     await wait();
 
-    expect(props.buffer.setText).toHaveBeenCalledWith('/help ');
+    expect(props.buffer.setText).toHaveBeenCalledWith('/help');
     unmount();
   });
 
@@ -505,7 +504,6 @@ describe('InputPrompt', () => {
     await wait();
 
     expect(props.onSubmit).toHaveBeenCalledWith('/clear');
-    expect(props.buffer.setText).not.toHaveBeenCalledWith('/clear ');
     unmount();
   });
 
@@ -530,7 +528,10 @@ describe('InputPrompt', () => {
   });
 
   it('should add a newline on enter when the line ends with a backslash', async () => {
-    props.buffer.setText('first line\\');
+    // This test simulates multi-line input, not submission
+    mockBuffer.text = 'first line\\';
+    mockBuffer.cursor = [0, 11];
+    mockBuffer.lines = ['first line\\'];
 
     const { stdin, unmount } = render(<InputPrompt {...props} />);
     await wait();
diff --git a/packages/cli/src/ui/components/InputPrompt.tsx b/packages/cli/src/ui/components/InputPrompt.tsx
index 01ed8db1..4d66b10c 100644
--- a/packages/cli/src/ui/components/InputPrompt.tsx
+++ b/packages/cli/src/ui/components/InputPrompt.tsx
@@ -162,7 +162,7 @@ export const InputPrompt: React.FC<InputPromptProps> = ({
         // - Otherwise, the base is everything EXCEPT the last partial part.
         const basePath =
           hasTrailingSpace || isParentPath ? parts : parts.slice(0, -1);
-        const newValue = `/${[...basePath, suggestion].join(' ')} `;
+        const newValue = `/${[...basePath, suggestion].join(' ')}`;
 
         buffer.setText(newValue);
       } else {
@@ -266,6 +266,12 @@ export const InputPrompt: React.FC<InputPromptProps> = ({
         return;
       }
 
+      // If the command is a perfect match, pressing enter should execute it.
+      if (completion.isPerfectMatch && key.name === 'return') {
+        handleSubmitAndClear(buffer.text);
+        return;
+      }
+
       if (completion.showSuggestions) {
         if (completion.suggestions.length > 1) {
           if (key.name === 'up') {
diff --git a/packages/cli/src/ui/hooks/useCompletion.test.ts b/packages/cli/src/ui/hooks/useCompletion.test.ts
index 7f2823c7..267bce13 100644
--- a/packages/cli/src/ui/hooks/useCompletion.test.ts
+++ b/packages/cli/src/ui/hooks/useCompletion.test.ts
@@ -4,6 +4,8 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
+/** @vitest-environment jsdom */
+
 import { describe, it, expect, beforeEach, vi, afterEach } from 'vitest';
 import type { Mocked } from 'vitest';
 import { renderHook, act } from '@testing-library/react';
diff --git a/packages/cli/src/ui/hooks/useCompletion.ts b/packages/cli/src/ui/hooks/useCompletion.ts
index d3de5c6b..81acc992 100644
--- a/packages/cli/src/ui/hooks/useCompletion.ts
+++ b/packages/cli/src/ui/hooks/useCompletion.ts
@@ -28,6 +28,7 @@ export interface UseCompletionReturn {
   visibleStartIndex: number;
   showSuggestions: boolean;
   isLoadingSuggestions: boolean;
+  isPerfectMatch: boolean;
   setActiveSuggestionIndex: React.Dispatch<React.SetStateAction<number>>;
   setShowSuggestions: React.Dispatch<React.SetStateAction<boolean>>;
   resetCompletionState: () => void;
@@ -50,6 +51,7 @@ export function useCompletion(
   const [showSuggestions, setShowSuggestions] = useState<boolean>(false);
   const [isLoadingSuggestions, setIsLoadingSuggestions] =
     useState<boolean>(false);
+  const [isPerfectMatch, setIsPerfectMatch] = useState<boolean>(false);
 
   const resetCompletionState = useCallback(() => {
     setSuggestions([]);
@@ -57,6 +59,7 @@ export function useCompletion(
     setVisibleStartIndex(0);
     setShowSuggestions(false);
     setIsLoadingSuggestions(false);
+    setIsPerfectMatch(false);
   }, []);
 
   const navigateUp = useCallback(() => {
@@ -127,6 +130,9 @@ export function useCompletion(
     const trimmedQuery = query.trimStart();
 
     if (trimmedQuery.startsWith('/')) {
+      // Always reset perfect match at the beginning of processing.
+      setIsPerfectMatch(false);
+
       const fullPath = trimmedQuery.substring(1);
       const hasTrailingSpace = trimmedQuery.endsWith(' ');
 
@@ -183,6 +189,23 @@ export function useCompletion(
         }
       }
 
+      // Check for perfect, executable match
+      if (!hasTrailingSpace) {
+        if (leafCommand && partial === '' && leafCommand.action) {
+          // Case: /command<enter> - command has action, no sub-commands were suggested
+          setIsPerfectMatch(true);
+        } else if (currentLevel) {
+          // Case: /command subcommand<enter>
+          const perfectMatch = currentLevel.find(
+            (cmd) =>
+              (cmd.name === partial || cmd.altName === partial) && cmd.action,
+          );
+          if (perfectMatch) {
+            setIsPerfectMatch(true);
+          }
+        }
+      }
+
       const depth = commandPathParts.length;
 
       // Provide Suggestions based on the now-corrected context
@@ -223,7 +246,7 @@ export function useCompletion(
           const perfectMatch = potentialSuggestions.find(
             (s) => s.name === partial || s.altName === partial,
           );
-          if (perfectMatch && !perfectMatch.subCommands) {
+          if (perfectMatch && perfectMatch.action) {
             potentialSuggestions = [];
           }
         }
@@ -534,6 +557,7 @@ export function useCompletion(
     visibleStartIndex,
     showSuggestions,
     isLoadingSuggestions,
+    isPerfectMatch,
     setActiveSuggestionIndex,
     setShowSuggestions,
     resetCompletionState,