fix(agents): exec_command states the 30 s yield cap and that a running non-TTY process cannot be polled

strix/agents/factory.py

@@ -13,6 +13,7 @@ from agents.agent import ToolsToFinalOutputResult
 from agents.sandbox import SandboxAgent
 from agents.sandbox.capabilities import Filesystem, Shell
 from agents.sandbox.errors import InvalidManifestPathError
+from agents.sandbox.session.pty_types import PTY_YIELD_TIME_MS_MAX
 from agents.tool import CustomTool, FunctionTool, Tool
 from pydantic import ValidationError
 
@@ -441,8 +442,43 @@ def _apply_shell_output_cap(parsed: dict[str, Any]) -> None:
     )
 
 
+_EXEC_YIELD_CAP_S = PTY_YIELD_TIME_MS_MAX // 1000
+
+_EXEC_COMMAND_DESCRIPTION_NOTE = (
+    f"The wait for output is capped at {_EXEC_YIELD_CAP_S} s whatever yield_time_ms says. "
+    "A non-TTY command still running at the yield cannot be read later (write_stdin fails "
+    "on it and its output is lost): run anything longer in the background with its output "
+    "redirected to a file (`cmd > /tmp/out.log 2>&1 &`, then read the log), or start it with "
+    'tty=true and poll with write_stdin(session_id=<id>, chars="").'
+)
+
+_RUNNING_NON_TTY_NOTICE = (
+    "Note: this non-TTY process cannot be polled and its later output is lost. Rerun it in "
+    "the background (`cmd > /tmp/out.log 2>&1 &`, then read the log) or with tty=true."
+)
+
+_PROCESS_RUNNING_RE = re.compile(r"^Process running with session ID \d+$", re.MULTILINE)
+
+
+def _annotate_running_non_tty(parsed: dict[str, Any], result: Any) -> Any:
+    if parsed.get("tty") or not isinstance(result, str):
+        return result
+    match = _PROCESS_RUNNING_RE.search(result)
+    if match is None:
+        return result
+    notice = _RUNNING_NON_TTY_NOTICE
+    requested = parsed.get("yield_time_ms")
+    if isinstance(requested, int | float) and requested > PTY_YIELD_TIME_MS_MAX:
+        notice = (
+            f"Note: yield_time_ms={int(requested)} was capped at {PTY_YIELD_TIME_MS_MAX} "
+            f"({_EXEC_YIELD_CAP_S} s). " + notice.removeprefix("Note: ")
+        )
+    return f"{result[: match.end()]}\n{notice}{result[match.end() :]}"
+
+
 def _wrap_exec_command(tool: FunctionTool) -> FunctionTool:
     invoke_tool = tool.on_invoke_tool
+    tool.description = f"{tool.description.rstrip()} {_EXEC_COMMAND_DESCRIPTION_NOTE}"
 
     async def invoke(ctx: Any, raw_input: str) -> Any:
         try:
@@ -455,7 +491,7 @@ def _wrap_exec_command(tool: FunctionTool) -> FunctionTool:
             _apply_shell_output_cap(parsed)
             raw_input = json.dumps(parsed)
         try:
-            return await invoke_tool(ctx, raw_input)
+            result = await invoke_tool(ctx, raw_input)
         except ValidationError as exc:
             return _format_validation_error(tool.name, exc)
         except InvalidManifestPathError as exc:
@@ -465,6 +501,9 @@ def _wrap_exec_command(tool: FunctionTool) -> FunctionTool:
                 "(or omitted to use the turn's cwd). "
                 f"Got: {rel!r}."
             )
+        if isinstance(parsed, dict):
+            return _annotate_running_non_tty(parsed, result)
+        return result
 
     tool.on_invoke_tool = invoke
     return tool

tests/test_agent_factory_shell.py

@@ -80,6 +80,79 @@ async def test_wrap_exec_command_preserves_explicit_shell(shell: str) -> None:
     assert json.loads(captured["raw_input"])["shell"] == shell
 
 
+def _running_exec_tool(result: str) -> FunctionTool:
+    async def invoke(_ctx: Any, _raw_input: str) -> str:
+        return result
+
+    return FunctionTool(
+        name="exec_command",
+        description="Runs a command.",
+        params_json_schema={"type": "object", "properties": {}},
+        on_invoke_tool=invoke,
+    )
+
+
+_RUNNING_RESULT = (
+    "Chunk ID: abc123\nWall time: 30.0012 seconds\nProcess running with session ID 7\nOutput:\n"
+)
+
+
+def test_wrap_exec_command_describes_the_yield_cap() -> None:
+    wrapped = factory._wrap_exec_command(_running_exec_tool("ok"))
+
+    assert wrapped.description.startswith("Runs a command. The wait for output is capped at 30 s")
+    assert "cannot be read later" in wrapped.description
+    assert "tty=true" in wrapped.description
+
+
+@pytest.mark.asyncio
+async def test_wrap_exec_command_flags_a_running_non_tty_process() -> None:
+    wrapped = factory._wrap_exec_command(_running_exec_tool(_RUNNING_RESULT))
+
+    result = await wrapped.on_invoke_tool(
+        cast("Any", None), json.dumps({"cmd": "sleep 60; curl x", "yield_time_ms": 90000})
+    )
+
+    assert result == (
+        "Chunk ID: abc123\nWall time: 30.0012 seconds\n"
+        "Process running with session ID 7\n"
+        "Note: yield_time_ms=90000 was capped at 30000 (30 s). this non-TTY process cannot be "
+        "polled and its later output is lost. Rerun it in the background "
+        "(`cmd > /tmp/out.log 2>&1 &`, then read the log) or with tty=true.\nOutput:\n"
+    )
+
+
+@pytest.mark.asyncio
+async def test_wrap_exec_command_flags_a_running_non_tty_process_within_the_cap() -> None:
+    wrapped = factory._wrap_exec_command(_running_exec_tool(_RUNNING_RESULT))
+
+    result = await wrapped.on_invoke_tool(cast("Any", None), json.dumps({"cmd": "sleep 60"}))
+
+    assert "Note: this non-TTY process cannot be polled" in result
+    assert "was capped" not in result
+
+
+@pytest.mark.asyncio
+async def test_wrap_exec_command_leaves_a_running_tty_process_alone() -> None:
+    wrapped = factory._wrap_exec_command(_running_exec_tool(_RUNNING_RESULT))
+
+    result = await wrapped.on_invoke_tool(
+        cast("Any", None), json.dumps({"cmd": "python3 -m http.server", "tty": True})
+    )
+
+    assert result == _RUNNING_RESULT
+
+
+@pytest.mark.asyncio
+async def test_wrap_exec_command_leaves_an_exited_process_alone() -> None:
+    exited = "Chunk ID: abc123\nWall time: 0.1 seconds\nProcess exited with code 0\nOutput:\nhi"
+    wrapped = factory._wrap_exec_command(_running_exec_tool(exited))
+
+    result = await wrapped.on_invoke_tool(cast("Any", None), json.dumps({"cmd": "echo hi"}))
+
+    assert result == exited
+
+
 @pytest.mark.asyncio
 async def test_responses_filesystem_custom_tool_output_is_bounded() -> None:
     async def invoke(_ctx: Any, _inp: str) -> str: