# Terminal support

## Color

When the client reports truecolor, new panes get `TERM=xterm-direct` and `COLORTERM=truecolor`; otherwise `TERM=xterm-256color`. The capability travels inside vev's own protocol, so it works over SSH without `SendEnv`/`AcceptEnv`. Panes restored from a snapshot start conservative until a client attaches.

## Environment

On each attach, the attaching environment becomes the session's source of truth for future PTY children. vev preserves it except that it replaces `TERM`, `COLORTERM`, `TERM_PROGRAM`, and `VEV`; `SHELL` selects the command used to start each PTY. Already-running processes keep their original environment.

For remote attaches, the remote proxy substitutes the remote host's exported environment, so remote PTYs do not inherit the local client's environment.

## VT compatibility

vev keeps a server-side VT screen per pane: scroll regions (DECOM), insert mode, cursor and mode-query reports, alternate screen, bracketed paste, mouse tracking, synchronized updates, OSC 9/777 notifications, OSC 52 clipboard, and double-width cells. Resizes repair double-width cells so CJK and emoji halves are never left behind.

## Recovery

Named-session checkpoints preserve bounded scrollback and a recovery transcript containing the primary viewport followed by the active alternate viewport, when present. Each viewport trims only trailing untouched blank rows; leading, internal, styled, and otherwise touched blank rows remain.

On restore, vev appends the transcript after bounded scrollback as copy-mode history on a fresh blank VT screen. A resumed allowlisted process can redraw the live screen without erasing that recovered history. Recovery does not replay the PTY stream or restore the previous cursor or terminal modes.

## Alt+Space caveat

Some terminals encode Alt+Space as a non-breaking space instead of `ESC Space`. If the palette does not open, rebind `open-palette`.