Filter Jupyter terminal wrapper output

src/jupyter_runtime.py

@@ -535,6 +535,7 @@ PY
         if not command.strip():
             raise JupyterRuntimeError('Remote command is empty.')
         marker = f'__ZK_AGENT_EXIT_{uuid.uuid4().hex}__'
+        start_marker = f'__ZK_AGENT_START_{uuid.uuid4().hex}__'
         workspace = shlex.quote(self.binding.workspace_cwd)
         run_dir = f'{self.binding.workspace_cwd}/scratchpad/.run_pids'
         quoted_run_dir = shlex.quote(run_dir)
@@ -544,6 +545,7 @@ PY
         wrapped = (
             f'mkdir -p {workspace} {quoted_run_dir} && '
             f'cd {workspace} && '
+            f'printf "\\n{start_marker}\\n"; '
             f'( setsid bash -lc {shlex.quote(inner_command)} ) & '
             '__zk_pid=$!; '
             f'printf "%s\\n" "$__zk_pid" > {pid_file}; '
@@ -581,6 +583,7 @@ PY
                 return self._collect_until_marker(
                     ws,
                     marker=marker,
+                    start_marker=start_marker,
                     timeout_seconds=timeout_seconds,
                     max_output_chars=max_output_chars,
                     cancel_event=cancel_event,
@@ -1079,6 +1082,7 @@ else:
         ws: Any,
         *,
         marker: str,
+        start_marker: str,
         timeout_seconds: float,
         max_output_chars: int,
         cancel_event: Any | None,
@@ -1117,12 +1121,22 @@ else:
                 pass
             return RemoteCommandResult(
                 exit_code=124,
-                stdout=truncate_text(''.join(transcript), max_output_chars),
+                stdout=truncate_text(
+                    extract_terminal_command_output(
+                        clean_terminal_output(''.join(transcript)),
+                        start_marker=start_marker,
+                    ),
+                    max_output_chars,
+                ),
                 timed_out=True,
             )
+        stdout = extract_terminal_command_output(
+            clean_terminal_output(''.join(transcript)),
+            start_marker=start_marker,
+        )
         return RemoteCommandResult(
             exit_code=exit_code,
-            stdout=truncate_text(clean_terminal_output(''.join(transcript)), max_output_chars),
+            stdout=truncate_text(stdout, max_output_chars),
         )
 
     def _remote_write_text_command(self, path: str, content: str) -> str:
@@ -1279,6 +1293,16 @@ def clean_terminal_output(text: str) -> str:
     return '\n'.join(lines).strip('\r\n')
 
 
+def extract_terminal_command_output(text: str, *, start_marker: str) -> str:
+    """Drop terminal echo/prompt text before the wrapper's real start marker."""
+    if not start_marker:
+        return text
+    marker_index = text.rfind(start_marker)
+    if marker_index < 0:
+        return text
+    return text[marker_index + len(start_marker) :].lstrip('\r\n')
+
+
 def truncate_text(text: str, limit: int) -> str:
     if limit <= 0 or len(text) <= limit:
         return text

tests/test_jupyter_runtime.py

@@ -0,0 +1,40 @@
+from __future__ import annotations
+
+import unittest
+
+from src.jupyter_runtime import (
+    clean_terminal_output,
+    extract_terminal_command_output,
+)
+
+
+class TestJupyterRuntimeOutputFiltering(unittest.TestCase):
+    def test_extract_terminal_command_output_drops_wrapper_echo(self) -> None:
+        start_marker = '__ZK_AGENT_START_test__'
+        raw = (
+            'root@host:/workspace# mkdir -p /workspace && cd /workspace && '
+            'printf "\\n__ZK_AGENT_START_test__\\n"; '
+            '( setsid bash -lc \'export A=1; echo real-output\' ) &\r\n'
+            f'{start_marker}\r\n'
+            'real-output\r\n'
+        )
+
+        output = extract_terminal_command_output(
+            clean_terminal_output(raw),
+            start_marker=start_marker,
+        )
+
+        self.assertEqual(output, 'real-output')
+
+    def test_extract_terminal_command_output_uses_last_marker(self) -> None:
+        start_marker = '__ZK_AGENT_START_test__'
+        output = extract_terminal_command_output(
+            f'echo text containing {start_marker}\n{start_marker}\nactual',
+            start_marker=start_marker,
+        )
+
+        self.assertEqual(output, 'actual')
+
+
+if __name__ == '__main__':
+    unittest.main()