Fix: for terminals that don't send enter, submit with 'linefeed'

Author: jahooma

cli/src/components/chat-input-bar.tsx

@@ -12,6 +12,7 @@ import { useAskUserBridge } from '../hooks/use-ask-user-bridge'
 import { useEvent } from '../hooks/use-event'
 import { useChatStore } from '../state/chat-store'
 import { getInputModeConfig } from '../utils/input-modes'
+import { isLinefeedActingAsEnter } from '../utils/terminal-enter-detection'
 import { BORDER_CHARS } from '../utils/ui-constants'
 
 import type { useTheme } from '../hooks/use-theme'
@@ -131,7 +132,8 @@ export const ChatInputBar = ({
       option?: boolean
     }) => {
       const isPlainEnter =
-        (key.name === 'return' || key.name === 'enter') &&
+        (key.name === 'return' || key.name === 'enter' ||
+          (key.name === 'linefeed' && isLinefeedActingAsEnter())) &&
         !key.shift &&
         !key.ctrl &&
         !key.meta &&

cli/src/components/multiline-input.tsx

@@ -13,6 +13,7 @@ import { InputCursor } from './input-cursor'
 import { useTheme } from '../hooks/use-theme'
 import { useChatStore } from '../state/chat-store'
 import { clamp } from '../utils/math'
+import { isLinefeedActingAsEnter, markReturnKeySeen } from '../utils/terminal-enter-detection'
 import { supportsTruecolor } from '../utils/theme-system'
 import { calculateNewCursorPosition } from '../utils/word-wrap-utils'
 
@@ -523,11 +524,17 @@ export const MultilineInput = forwardRef<
   const handleEnterKeys = useCallback(
     (key: KeyEvent): boolean => {
       const lowerKeyName = (key.name ?? '').toLowerCase()
-      const isEnterKey = key.name === 'return' || key.name === 'enter'
-      // Ctrl+J is translated by the terminal to a linefeed character (0x0a)
-      // So we detect it by checking for name === 'linefeed' rather than ctrl + j
+      const isReturnOrEnter = key.name === 'return' || key.name === 'enter'
+
+      if (isReturnOrEnter) {
+        markReturnKeySeen()
+      }
+
+      const linefeedIsEnter = lowerKeyName === 'linefeed' && isLinefeedActingAsEnter()
+      const isEnterKey = isReturnOrEnter || linefeedIsEnter
+
       const isCtrlJ =
-        lowerKeyName === 'linefeed' ||
+        (lowerKeyName === 'linefeed' && !linefeedIsEnter) ||
         (key.ctrl &&
           !key.meta &&
           !key.option &&

cli/src/hooks/use-chat-keyboard.ts

@@ -12,6 +12,7 @@ import {
   type ChatKeyboardState,
   type ChatKeyboardAction,
 } from '../utils/keyboard-actions'
+import { markReturnKeySeen } from '../utils/terminal-enter-detection'
 
 import type { KeyEvent } from '@opentui/core'
 
@@ -304,6 +305,10 @@ export function useChatKeyboard({
           reportActivity()
         }
 
+        if (key.name === 'return' || key.name === 'enter') {
+          markReturnKeySeen()
+        }
+
         const action = resolveChatKeyboardAction(key, state)
         const handled = dispatchAction(action, handlers)
 

cli/src/utils/keyboard-actions.ts

@@ -1,4 +1,5 @@
 import { getInputModeConfig, type InputMode } from './input-modes'
+import { isLinefeedActingAsEnter } from './terminal-enter-detection'
 import type { KeyEvent } from '@opentui/core'
 
 
@@ -131,7 +132,8 @@ export function resolveChatKeyboardAction(
   const isShiftTab =
     key.name === 'tab' && key.shift && !key.ctrl && !key.meta && !key.option
   const isEnter =
-    (key.name === 'return' || key.name === 'enter') &&
+    (key.name === 'return' || key.name === 'enter' ||
+      (key.name === 'linefeed' && isLinefeedActingAsEnter())) &&
     !key.shift &&
     !hasModifier(key)
   const isPageUp = key.name === 'pageup' && !hasModifier(key)

cli/src/utils/terminal-enter-detection.ts

@@ -0,0 +1,17 @@
+/**
+ * Most terminals send \r for Enter and \n for Ctrl+J. A few niche Linux
+ * terminal emulators send \n for Enter instead, making the two
+ * indistinguishable. We detect this at runtime by tracking whether we've
+ * ever seen a \r ("return") key event. On macOS, Enter always sends \r.
+ */
+
+let hasSeenReturnKey = process.platform === 'darwin'
+
+export function markReturnKeySeen(): void {
+  hasSeenReturnKey = true
+}
+
+/** True when a "linefeed" (\n) key event should be treated as Enter. */
+export function isLinefeedActingAsEnter(): boolean {
+  return !hasSeenReturnKey
+}