usestrix/strix · error · ValueError

{name} must be a non-empty string

Error message

{name} must be a non-empty string

What it means

Raised by the controller's _required_string helper (controller.py:483) whenever a payload field must be a non-empty trimmed string but the value is not a str instance, is empty, or is only whitespace. Used for agent_id and message fields across handlers. The value is returned stripped, so leading/trailing whitespace is tolerated but the stripped result must be non-empty.

Source

Thrown at strix/interface/tui/backend/controller.py:483

        if httpd is None:
            return
        self._viewer_httpd = None
        with contextlib.suppress(Exception):
            httpd.shutdown()
            httpd.server_close()

    async def _quit(self, _payload: dict[str, Any]) -> dict[str, Any]:
        self.close_viewer()
        if self._on_quit is not None:
            await self._on_quit()
        self.scan_state = "stopped"
        return {"quitting": True}

    @staticmethod
    def _required_string(payload: dict[str, Any], name: str) -> str:
        value = payload.get(name)
        if not isinstance(value, str) or not value.strip():
            raise ValueError(f"{name} must be a non-empty string")
        return value.strip()

    def _require_setup_mutable(self) -> None:
        if not self.setup_mode or self.scan_started or self._start_in_progress:
            raise RuntimeError("Setup can no longer be changed after the scan starts")

View on GitHub (pinned to 8551339130)

Solutions

1. Validate the field client-side before dispatch: non-null string with non-whitespace content
2. Use .strip() on the input and check for emptiness before sending
3. Disable submit buttons while the required field is blank
4. Ensure ids stay strings end-to-end (no JSON number coercion)

Example fix

# before
await controller._send_message({"agent_id": aid, "message": "   "})

# after
msg = user_input.strip()
if msg:
    await controller._send_message({"agent_id": aid, "message": msg})

def valid_required_string(payload: dict, name: str) -> bool:
    v = payload.get(name)
    return isinstance(v, str) and bool(v.strip())

def is_non_empty_str(v) -> bool:
    return isinstance(v, str) and len(v.strip()) > 0

try:
    await controller._send_message(payload)
except ValueError as e:
    if "must be a non-empty string" in str(e):
        highlight_blank_field(payload)  # user-facing fix prompt
    else:
        raise

When it happens

Trigger: Dispatching a command with {"agent_id": ""}, {"agent_id": " "}, {"agent_id": 123}, {"agent_id": null}, or the key missing (payload.get returns None). Any handler that calls _required_string(payload, name) rejects these.

Common situations: UI sending an empty chat box submission; frontend passing numeric ids; null from optional form fields; whitespace-only input from copy-paste; test payloads built with placeholder values.

Related errors

• approved must be a boolean
• Unknown agent: {agent_id}
• instruction must be a string
• verify must be a boolean
• mount_working_dir must be a boolean

AI-assisted analysis of usestrix/strix@8551339130 (2026-08-15). Data as JSON: /api/errors/816dfb8c30cbf374. Report an issue: GitHub.