After host verification, enter the SSH login name, allow agent access and list identities. Choose one public fingerprint, then Open terminal. This consumes that selection; the alternative Check selected identity still authenticates and closes without a terminal. A fresh connection always requires a fresh explicit identity listing and verified host handshake.
The graphical prototype uses pinned xterm.js 6.0.0 and addon-fit 0.11.0, bundled locally and loaded only when explicitly opening a terminal. Renderer loading finishes before the native connection starts; a load error cancels the selection. The parent retains socket ownership during lazy rendering and cancellation. Text input is UTF-8; xterm binary input stays raw. Send Ctrl-C emits byte 3, while Disconnect closes the current Rust-owned session. Resizing the terminal container propagates dimensions, clamped to the native limit of 500. After closure, choose/list an identity again rather than replaying a consumed ID.
The native PTY transport stays in Rust. The renderer reads one bounded event at a time, waits for xterm's parsed-write callback, then requests the next block. It never independently decodes output chunks, so split UTF-8 sequences reach xterm intact. Scrollback is limited to 1000 lines. Frontend input is serialized into at most 32 KiB messages with a 128 KiB pending-byte limit; resize bursts coalesce. Native queue saturation retries the same input for at most one second. Any overflow or persistent write failure visibly closes the session rather than silently losing input.
Superseded/unmounted sessions ignore late reads and failures. A start result that arrives after cancellation is immediately closed. StrictMode's discarded initial effect starts no reader and cannot close the surviving session. Endpoint/login edits, relisting and leaving the host-trust screen dispose the old terminal. The native window lifecycle also closes its owned socket independently of JavaScript.
No remote HTML, title or link is applied to the application; OSC 52 clipboard access is consumed without action. There is no link/clipboard addon, remote-font loader, agent forwarding or external runtime script. Terminal data and keystrokes stay within the bundled renderer/native SSH path and are not logged or sent to the control plane. As with any terminal, content can influence terminal state; this prototype is not a sandbox for arbitrary untrusted applications.
Unread output that remains blocked for three seconds fails and closes the connection. The pinned SSH library can otherwise stop processing outgoing Ctrl-C while its receive queue is full. A backgrounded/suspended renderer may therefore lose its session. Active output consumers can interrupt a fast producer; a fully paused consumer gets an explicit failure instead of an indefinite hang. See ADR 0014.
make check-client compiles the renderer and runs seven Node tests of the actual
transport controller: output backpressure, binary/split UTF-8 preservation,
serialized bounded input, resize coalescing, full-queue retries, overflow, stale
results and exit/EOF/close. They use simulated native calls, not SSH.
make check-terminal-webkit optionally exercises the real xterm renderer and
React development UI in macOS WebKit with isolated simulated IPC. Its
fixture boundary is explicit. Native
Rust tests exercise the product agent/PTY path against both generated protocol
fixtures and an actual local OS shell, including real resize/Ctrl-C and owned
process cleanup. make check-ssh retains its separate actual-shell exercise.
make check-terminal-native exercises the compiled frontend, lazy terminal/CSS,
Tauri's actual IPC/custom asset protocol and existing CSP in a separate optimized
macOS example with private trust, an incognito WebView and a disposable agent/
real shell. The scenario verifies first-use confirmation against generated public
metadata, trusted reinspection, exact identity selection, actual stdout/stty rows
after resize, Ctrl-C/status 130 within two seconds and disconnect/reconnect.
Generated host-key rotation is refused through the actual UI with no further
authentication or persisted-trust overwrite.
See native fixture boundaries.
Normal application startup configuration, physical keyboard/IME behavior, real
guest/OpenSSH/agent interoperability, installers/signing and mobile lifecycle
still require their own walkthroughs. The example uses the product command source
and frontend but does not replace those platform/infrastructure gates.
The main bundle is about 246 KiB and the lazy terminal about 335 KiB before gzip;
the original large-main-chunk warning is gone. STATE.md records actual build
and test evidence; none of these local fixtures closes the real-host Phase 0 gate.
Primary references: xterm terminal API, flow control, embedding security.