Function isSynchronizedOutputSupported

src/ink/terminal.ts:70–118

()

 * When supported, BSU/ESU sequences prevent visible flicker during redraws.
 */
export function isSynchronizedOutputSupported(): boolean {
  // tmux parses and proxies every byte but doesn't implement DEC 2026.
  // BSU/ESU pass through to the outer terminal but tmux has already
  // broken atomicity by chunking. Skip to save 16 bytes/frame + parser work.
  if (process.env.TMUX) return false

  const termProgram = process.env.TERM_PROGRAM
  const term = process.env.TERM

  // Modern terminals with known DEC 2026 support
  if (
    termProgram === 'iTerm.app' ||
    termProgram === 'WezTerm' ||
    termProgram === 'WarpTerminal' ||
    termProgram === 'ghostty' ||
    termProgram === 'contour' ||
    termProgram === 'vscode' ||
    termProgram === 'alacritty'
  ) {
    return true
  }

  // kitty sets TERM=xterm-kitty or KITTY_WINDOW_ID
  if (term?.includes('kitty') || process.env.KITTY_WINDOW_ID) return true

  // Ghostty may set TERM=xterm-ghostty without TERM_PROGRAM
  if (term === 'xterm-ghostty') return true

  // foot sets TERM=foot or TERM=foot-extra
  if (term?.startsWith('foot')) return true

  // Alacritty may set TERM containing 'alacritty'
  if (term?.includes('alacritty')) return true

  // Zed uses the alacritty_terminal crate which supports DEC 2026
  if (process.env.ZED_TERM) return true

  // Windows Terminal
  if (process.env.WT_SESSION) return true

  // VTE-based terminals (GNOME Terminal, Tilix, etc.) since VTE 0.68
  const vteVersion = process.env.VTE_VERSION
  if (vteVersion) {
    const version = parseInt(vteVersion, 10)
    if (version >= 6800) return true
  }

  return false
}

// -- XTVERSION-detected terminal name (populated async at startup) --
//