Method start

libs/code/deepagents_code/server.py:443–541

Start the `langgraph dev` server and wait for it to be healthy. Args: timeout: Max seconds to wait for the server to become healthy. Raises: RuntimeError: If the server fails to start or become healthy.

(
        self,
        *,
        timeout: float = _HEALTH_TIMEOUT,  # noqa: ASYNC109
    )

            return ""

    async def start(
        self,
        *,
        timeout: float = _HEALTH_TIMEOUT,  # noqa: ASYNC109
    ) -> None:
        """Start the `langgraph dev` server and wait for it to be healthy.

        Args:
            timeout: Max seconds to wait for the server to become healthy.

        Raises:
            RuntimeError: If the server fails to start or become healthy.
        """
        if self.running:
            return

        work_dir = self.config_dir
        if work_dir is None:
            self._temp_dir = tempfile.TemporaryDirectory(prefix="deepagents_server_")
            work_dir = Path(self._temp_dir.name)

        config_path = work_dir / "langgraph.json"
        if not config_path.exists() and self._scaffold is not None:
            # The config can vanish between the initial boot and a later
            # `/restart` (e.g. the OS tmp reaper purging the temp work dir).
            # Rebuild it rather than failing the restart.
            logger.info("langgraph.json missing in %s; rescaffolding", work_dir)
            try:
                work_dir.mkdir(parents=True, exist_ok=True)
                self._scaffold(work_dir)
            except OSError as exc:
                # Surface the failure with restart context instead of letting a
                # bare OSError (e.g. ENOSPC/EACCES on a degraded temp fs) escape
                # stripped of the recovery framing. Chained so the root cause
                # stays in the traceback.
                msg = f"Failed to rescaffold server workspace at {work_dir}: {exc}"
                raise RuntimeError(msg) from exc
        if not config_path.exists():
            if self._scaffold is not None:
                # The scaffold hook ran but produced no langgraph.json (a silent
                # no-op or a write to the wrong path). The "call
                # generate_langgraph_json() first" advice below would misdirect,
                # since the scaffold is exactly that call run internally.
                contents = sorted(p.name for p in work_dir.iterdir())
                msg = (
                    f"Rescaffolding {work_dir} did not produce langgraph.json "
                    f"(directory contents: {contents})."
                )
            else:
                msg = (
                    f"langgraph.json not found in {work_dir}. "
                    "Call generate_langgraph_json() first."
                )
            raise RuntimeError(msg)

        if self.port == _EPHEMERAL_PORT:
            self.port = _find_free_port(self.host)
            logger.info("Using ephemeral port %d for langgraph dev server", self.port)