fix(webcrt): restore full login transcript on attach

Keep the complete session_log replay including the final prompt, and stop clearing bootstrap on attach so StrictMode remounts do not blank the CRT.

Co-authored-by: Cursor <cursoragent@cursor.com>

netx_api/webcrt_router.py

@@ -98,7 +98,7 @@ async def websocket_session(websocket: WebSocket, session_id: str) -> None:
         }
     )
 
-    # Replay login transcript once, then draw a live prompt so first keystrokes match later lines.
+    # Replay full login transcript (kept for StrictMode remount / brief reconnect).
     bootstrap = bytes(sess.bootstrap_output or b"")
     if bootstrap:
         try:
@@ -107,8 +107,6 @@ async def websocket_session(websocket: WebSocket, session_id: str) -> None:
             )
         except Exception:
             _log.debug("webcrt bootstrap send failed session=%s", session_id, exc_info=True)
-        # Only replay login banner on the first attach (StrictMode remount / blip).
-        sess.bootstrap_output = b""
 
     stop = asyncio.Event()
 

netx_api/webcrt_service.py

@@ -158,24 +158,13 @@ def normalize_cli_transcript(text: str) -> str:
     return "\n".join(lines)
 
 
-def strip_trailing_prompt_lines(text: str) -> str:
-    """Remove final prompt line(s) so a live RETURN can paint the interactive prompt."""
-    lines = str(text or "").split("\n")
-    while lines and not str(lines[-1]).strip():
-        lines.pop()
-    while lines and _looks_like_cli_prompt(lines[-1]):
-        lines.pop()
-        while lines and not str(lines[-1]).strip():
-            lines.pop()
-    return "\n".join(lines)
-
-
 def prepare_bootstrap_output(text: str) -> str:
-    """Login transcript for UI replay; ends with newline, without the final prompt."""
-    body = strip_trailing_prompt_lines(normalize_cli_transcript(text))
-    if not body:
-        return ""
-    return body if body.endswith("\n") else body + "\n"
+    """Full login transcript for UI replay; keep final prompt, no trailing newline after it.
+
+    Trailing newline would leave the cursor on a blank line so the first typed line
+    looks wrong; cursor should sit after the prompt like a real CRT.
+    """
+    return normalize_cli_transcript(text)
 
 
 def _prime_interactive_channel(conn: ConnectHandler) -> None:
@@ -491,9 +480,7 @@ def create_session(
         except Exception:
             pass
 
-    # Prefer session_log (full login transcript). Prime channel, then strip the final
-    # prompt so WebSocket attach can paint a live interactive prompt (first keystrokes
-    # then behave like subsequent lines).
+    # Prefer session_log (full login transcript including final prompt).
     _prime_interactive_channel(conn)
     bootstrap = prepare_bootstrap_output(_session_log_text(log_buf))
     if not bootstrap.strip():
@@ -522,7 +509,8 @@ def create_session(
         cli_keymap=cli_keymap,
         conn=conn,
         bootstrap_output=str(bootstrap or "").encode("utf-8", errors="replace"),
-        needs_live_prompt=True,
+        # Only nudge a live prompt when transcript has no recognizable prompt yet.
+        needs_live_prompt=not _looks_like_cli_prompt(bootstrap),
     )
     # Keep bootstrap for WS attach replay; do not rely solely on out_queue (StrictMode remount).
     sess.start_reader()

tests/test_webcrt.py

@@ -79,9 +79,8 @@ class WebcrtServiceTests(unittest.TestCase):
         self.assertEqual(svc.map_network_cli_enter("\r", telnet), "\r\n")  # type: ignore[arg-type]
         self.assertEqual(svc.normalize_cli_transcript("R2#R2#\nR2#"), "R2#")
         self.assertEqual(svc.normalize_cli_transcript("banner\nR2#R2#"), "banner\nR2#")
-        self.assertEqual(svc.prepare_bootstrap_output("login\nR2#\nR2#"), "login\n")
-        self.assertTrue(svc.prepare_bootstrap_output("login\nR2#").endswith("\n"))
-        self.assertFalse(svc._looks_like_cli_prompt(svc.prepare_bootstrap_output("login\nR2#").rstrip("\n") or "x"))
+        self.assertEqual(svc.prepare_bootstrap_output("login\nR2#\nR2#"), "login\nR2#")
+        self.assertTrue(svc.prepare_bootstrap_output("login\nR2#").endswith("R2#"))
 
     @patch.object(svc, "_audit")
     @patch.object(svc, "open_netmiko_connection")
@@ -172,9 +171,8 @@ class WebcrtServiceTests(unittest.TestCase):
         assert sess is not None
         boot = sess.bootstrap_output.decode("utf-8", errors="replace")
         self.assertIn("Username:huawei", boot)
-        # Final prompt is stripped; live RETURN on WS attach paints the interactive prompt.
-        self.assertNotIn("<r1>", boot)
-        self.assertTrue(sess.needs_live_prompt)
+        self.assertIn("<r1>", boot)
+        self.assertFalse(sess.needs_live_prompt)
         before = list(fake.written)
         sess.write_stdin("\n")
         self.assertEqual(fake.written[len(before) :], ["\n"])