deepseek-ai/deepseek-harness · error · TransportClosedError

DeepSeek Harness runtime is not running

Error message

DeepSeek Harness runtime is not running

What it means

Error "DeepSeek Harness runtime is not running" thrown in deepseek-ai/deepseek-harness.

Source

Thrown at python/sdk/src/deepseek_harness/client.py:301

                except queue.Empty:
                    continue
        except BaseException:
            with self._lock:
                self._responses.pop(request_id, None)
            if temp_subscription is not None:
                temp_subscription.close()
            raise
        finally:
            if temp_subscription is not None:
                temp_subscription.close()
        if isinstance(item, BaseException):
            raise item
        return item

    def _write_message(self, message: JsonObject) -> None:
        proc = self._proc
        if proc is None or proc.stdin is None:
            raise TransportClosedError("DeepSeek Harness runtime is not running")
        try:
            payload = json.dumps(message, separators=(",", ":")) + "\n"
            with self._write_lock:
                proc.stdin.write(payload)
                proc.stdin.flush()
        except Exception as exc:
            raise self._runtime_closed_error("Failed to write to DeepSeek Harness runtime") from exc

    def _start_reader_thread(self) -> None:
        self._reader_thread = threading.Thread(target=self._reader_loop, name="dsh-runtime-reader", daemon=True)
        self._reader_thread.start()

    def _start_stderr_thread(self) -> None:
        self._stderr_thread = threading.Thread(target=self._stderr_loop, name="dsh-runtime-stderr", daemon=True)
        self._stderr_thread.start()

    def _reader_loop(self) -> None:
        proc = self._proc

View on GitHub (pinned to b150a551b8)

Solutions

1. Start or connect to the DeepSeek Harness runtime before issuing requests.

When it happens

Trigger: Thrown at python/sdk/src/deepseek_harness/client.py:301 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of deepseek-ai/deepseek-harness@b150a551b8 (2026-08-24). Data as JSON: /api/errors/43afa9f1cd97004b. Report an issue: GitHub.