Set terminal title per user input

Author: jahooma

cli/src/chat.tsx

@@ -73,6 +73,7 @@ import { computeInputLayoutMetrics } from './utils/text-layout'
 import { reportActivity } from './utils/activity-tracker'
 import { trackEvent } from './utils/analytics'
 import { logger } from './utils/logger'
+import { setTerminalTitle } from './utils/terminal-title'
 
 import type { CommandResult } from './commands/command-registry'
 import type { MatchedSlashCommand } from './hooks/use-suggestion-engine'
@@ -808,6 +809,10 @@ export const Chat = ({
   const handleSubmit = useCallback(async () => {
     // Report activity for ad rotation
     reportActivity()
+    // Update terminal title with truncated user input
+    if (inputValue.trim()) {
+      setTerminalTitle(inputValue)
+    }
     const result = await onSubmitPrompt(inputValue, agentMode)
     handleCommandResult(result)
   }, [onSubmitPrompt, inputValue, agentMode, handleCommandResult])

cli/src/utils/renderer-cleanup.ts

@@ -1,5 +1,7 @@
 import type { CliRenderer } from '@opentui/core'
 
+import { resetTerminalTitle } from './terminal-title'
+
 let renderer: CliRenderer | null = null
 let handlersInstalled = false
 let terminalStateReset = false
@@ -39,6 +41,8 @@ function resetTerminalState(): void {
   terminalStateReset = true
 
   try {
+    // Reset terminal title to default
+    resetTerminalTitle()
     // Write directly to stdout - this is synchronous and will complete
     // before the process exits, ensuring the terminal is reset
     process.stdout.write(TERMINAL_RESET_SEQUENCES)

cli/src/utils/terminal-title.ts

@@ -0,0 +1,105 @@
+/**
+ * Terminal title utilities using OSC (Operating System Command) escape sequences.
+ *
+ * OSC sequence format for setting title:
+ * - `\x1b]0;${title}\x07` - Sets both window title and icon name
+ * - `\x1b` is ESC, `]0;` starts the title command, `\x07` (BEL) ends it
+ *
+ * We write directly to /dev/tty to bypass OpenTUI's stdout capture,
+ * similar to how clipboard.ts handles OSC52 sequences.
+ */
+
+import { closeSync, constants, openSync, writeSync } from 'fs'
+
+const MAX_TITLE_LENGTH = 60
+const TITLE_PREFIX = 'Codebuff: '
+const OSC_TERMINATOR = '\x07' // BEL
+
+function isInTmux(): boolean {
+  return Boolean(process.env.TMUX)
+}
+
+function isInScreen(): boolean {
+  if (process.env.STY) return true
+  const term = process.env.TERM ?? ''
+  return term.startsWith('screen') && !isInTmux()
+}
+
+/**
+ * Build the OSC title sequence with tmux/screen passthrough if needed
+ */
+function buildTitleSequence(title: string): string {
+  const osc = `\x1b]0;${title}${OSC_TERMINATOR}`
+
+  // tmux passthrough: wrap in DCS and double ESC characters
+  if (isInTmux()) {
+    const escaped = osc.replace(/\x1b/g, '\x1b\x1b')
+    return `\x1bPtmux;${escaped}\x1b\\`
+  }
+
+  // GNU screen passthrough: wrap in DCS
+  if (isInScreen()) {
+    return `\x1bP${osc}\x1b\\`
+  }
+
+  return osc
+}
+
+/**
+ * Write an escape sequence directly to the controlling terminal.
+ * This bypasses OpenTUI's stdout capture by writing to /dev/tty directly.
+ */
+function writeToTty(sequence: string): boolean {
+  const ttyPath = process.platform === 'win32' ? 'CON' : '/dev/tty'
+
+  let fd: number | null = null
+  try {
+    fd = openSync(ttyPath, constants.O_WRONLY)
+    writeSync(fd, sequence)
+    return true
+  } catch {
+    return false
+  } finally {
+    if (fd !== null) {
+      try {
+        closeSync(fd)
+      } catch {
+        // Ignore close errors
+      }
+    }
+  }
+}
+
+/**
+ * Set the terminal window title.
+ * Works on most modern terminal emulators, including through tmux and screen.
+ *
+ * @param title - The title to set (will be truncated if too long)
+ */
+export function setTerminalTitle(title: string): void {
+  // Sanitize: remove control characters and newlines
+  const sanitized = title.replace(/[\x00-\x1f\x7f]/g, ' ').trim()
+  if (!sanitized) return
+
+  // Truncate to reasonable length
+  const maxInputLength = MAX_TITLE_LENGTH - TITLE_PREFIX.length
+  const truncated =
+    sanitized.length > maxInputLength
+      ? sanitized.slice(0, maxInputLength - 1) + '…'
+      : sanitized
+
+  const fullTitle = `${TITLE_PREFIX}${truncated}`
+  const sequence = buildTitleSequence(fullTitle)
+
+  writeToTty(sequence)
+}
+
+/**
+ * Reset the terminal title to the default.
+ * Call this when the CLI exits to restore the terminal to a clean state.
+ */
+export function resetTerminalTitle(): void {
+  // Empty title resets to terminal's default behavior
+  const sequence = buildTitleSequence('')
+  writeToTty(sequence)
+}