chatty-terminal

The model half of Chatty’s embedded terminal: a PTY running a shell and an alacritty_terminal Term fed from it. No UI toolkit and no async runtime, so it runs headless (the agent shell, Harbor runs) as well as under a view.

Public surface

• TerminalHandle::spawn(TerminalConfig) starts the shell ($SHELL login + interactive on Unix, pwsh/powershell over ConPTY on Windows) and returns the handle plus the event channel. Drop the receiver to run with no subscriber.
• spawn_with_tap(config, tap) adds a byte-stream tap: a callback that sees every byte read from the PTY before the parser does.
• TerminalConfig::scrollback sets the lines of history kept (default 10,000).
• MarkScanner (fed from the tap): OSC 133 A/B/C/D marks, chatty’s private OSC 6973, and the CleanText between them (no escapes, \r\n as \n, redrawn lines as they ended, no wrapping at the terminal width).
• commands() -> Vec<CommandRecord>: the last 200 commands run at a shell with OSC 133 integration (text after line editing, output line range, exit code, start/finish time, truncated once the output left the scrollback), and snapshot(Region::LastCommand): the last command’s output (end kept, capped at 16 KiB) with last_command saying what ran and how it exited, or that integration is not active. Line numbers come from a shadow Term in the byte tap, stopped at the exact byte of each mark (see src/commands.rs).
• Shell integration (TerminalConfig::shell_integration, default on): bash and zsh started with default arguments load chatty’s OSC 133 snippets (--rcfile / a ZDOTDIR wrapper, src/integration.rs) after the user’s own startup files, which are never edited. fish and PowerShell are unsupported and run without integration. With injection, bash is not a login shell to itself (shopt login_shell is off; our rcfile sources the login startup files instead), so a .bash_profile that branches on login_shell sees “not login”.
• write, resize, kill; dropping the handle kills the child’s process group and joins the PTY thread.
• has_foreground_job(): whether a program other than the shell holds the terminal’s foreground (the PTY’s foreground process group on Unix; None on Windows, where it cannot be told).
• foreground_process_name() and current_dir(): the foreground program’s name and the shell’s working directory, for tab titles (Linux, via /proc; None elsewhere).
• with_term reads the grid under its lock (for the renderer); generation() changes whenever content or size does.
• snapshot(Region) -> TerminalText: the screen, or the last N rows of scrollback, as plain text.

PtyWrite and TextAreaSizeRequest replies are written back to the PTY inside the crate, so programs that query the terminal work headless.

Tests

cargo test -p chatty-terminal spawns real shells under a PTY (Unix only). The zsh test runs when zsh is on PATH (or CHATTY_TEST_ZSH names one) and is skipped otherwise. The Windows ConPTY path compiles with cargo check --target x86_64-pc-windows-msvc -p chatty-terminal (verified locally). CI’s Windows check covers it once chatty-gpui or chatty-tui depend on this crate; the Windows runtime is untested.