dify

dify/api/core/mcp/client/sse_client.py

@@ -0,0 +1,360 @@
+import logging
+import queue
+from collections.abc import Generator
+from concurrent.futures import ThreadPoolExecutor
+from contextlib import contextmanager
+from typing import Any, TypeAlias, final
+from urllib.parse import urljoin, urlparse
+
+import httpx
+from httpx_sse import EventSource, ServerSentEvent
+from sseclient import SSEClient
+
+from core.mcp import types
+from core.mcp.error import MCPAuthError, MCPConnectionError
+from core.mcp.types import SessionMessage
+from core.mcp.utils import create_ssrf_proxy_mcp_http_client, ssrf_proxy_sse_connect
+
+logger = logging.getLogger(__name__)
+
+DEFAULT_QUEUE_READ_TIMEOUT = 3
+
+
+@final
+class _StatusReady:
+    def __init__(self, endpoint_url: str):
+        self.endpoint_url = endpoint_url
+
+
+@final
+class _StatusError:
+    def __init__(self, exc: Exception):
+        self.exc = exc
+
+
+# Type aliases for better readability
+ReadQueue: TypeAlias = queue.Queue[SessionMessage | Exception | None]
+WriteQueue: TypeAlias = queue.Queue[SessionMessage | Exception | None]
+StatusQueue: TypeAlias = queue.Queue[_StatusReady | _StatusError]
+
+
+class SSETransport:
+    """SSE client transport implementation."""
+
+    def __init__(
+        self,
+        url: str,
+        headers: dict[str, Any] | None = None,
+        timeout: float = 5.0,
+        sse_read_timeout: float = 1 * 60,
+    ):
+        """Initialize the SSE transport.
+
+        Args:
+            url: The SSE endpoint URL.
+            headers: Optional headers to include in requests.
+            timeout: HTTP timeout for regular operations.
+            sse_read_timeout: Timeout for SSE read operations.
+        """
+        self.url = url
+        self.headers = headers or {}
+        self.timeout = timeout
+        self.sse_read_timeout = sse_read_timeout
+        self.endpoint_url: str | None = None
+
+    def _validate_endpoint_url(self, endpoint_url: str) -> bool:
+        """Validate that the endpoint URL matches the connection origin.
+
+        Args:
+            endpoint_url: The endpoint URL to validate.
+
+        Returns:
+            True if valid, False otherwise.
+        """
+        url_parsed = urlparse(self.url)
+        endpoint_parsed = urlparse(endpoint_url)
+
+        return url_parsed.netloc == endpoint_parsed.netloc and url_parsed.scheme == endpoint_parsed.scheme
+
+    def _handle_endpoint_event(self, sse_data: str, status_queue: StatusQueue):
+        """Handle an 'endpoint' SSE event.
+
+        Args:
+            sse_data: The SSE event data.
+            status_queue: Queue to put status updates.
+        """
+        endpoint_url = urljoin(self.url, sse_data)
+        logger.info("Received endpoint URL: %s", endpoint_url)
+
+        if not self._validate_endpoint_url(endpoint_url):
+            error_msg = f"Endpoint origin does not match connection origin: {endpoint_url}"
+            logger.error(error_msg)
+            status_queue.put(_StatusError(ValueError(error_msg)))
+            return
+
+        status_queue.put(_StatusReady(endpoint_url))
+
+    def _handle_message_event(self, sse_data: str, read_queue: ReadQueue):
+        """Handle a 'message' SSE event.
+
+        Args:
+            sse_data: The SSE event data.
+            read_queue: Queue to put parsed messages.
+        """
+        try:
+            message = types.JSONRPCMessage.model_validate_json(sse_data)
+            logger.debug("Received server message: %s", message)
+            session_message = SessionMessage(message)
+            read_queue.put(session_message)
+        except Exception as exc:
+            logger.exception("Error parsing server message")
+            read_queue.put(exc)
+
+    def _handle_sse_event(self, sse: ServerSentEvent, read_queue: ReadQueue, status_queue: StatusQueue):
+        """Handle a single SSE event.
+
+        Args:
+            sse: The SSE event object.
+            read_queue: Queue for message events.
+            status_queue: Queue for status events.
+        """
+        match sse.event:
+            case "endpoint":
+                self._handle_endpoint_event(sse.data, status_queue)
+            case "message":
+                self._handle_message_event(sse.data, read_queue)
+            case _:
+                logger.warning("Unknown SSE event: %s", sse.event)
+
+    def sse_reader(self, event_source: EventSource, read_queue: ReadQueue, status_queue: StatusQueue):
+        """Read and process SSE events.
+
+        Args:
+            event_source: The SSE event source.
+            read_queue: Queue to put received messages.
+            status_queue: Queue to put status updates.
+        """
+        try:
+            for sse in event_source.iter_sse():
+                self._handle_sse_event(sse, read_queue, status_queue)
+        except httpx.ReadError as exc:
+            logger.debug("SSE reader shutting down normally: %s", exc)
+        except Exception as exc:
+            read_queue.put(exc)
+        finally:
+            read_queue.put(None)
+
+    def _send_message(self, client: httpx.Client, endpoint_url: str, message: SessionMessage):
+        """Send a single message to the server.
+
+        Args:
+            client: HTTP client to use.
+            endpoint_url: The endpoint URL to send to.
+            message: The message to send.
+        """
+        response = client.post(
+            endpoint_url,
+            json=message.message.model_dump(
+                by_alias=True,
+                mode="json",
+                exclude_none=True,
+            ),
+        )
+        response.raise_for_status()
+        logger.debug("Client message sent successfully: %s", response.status_code)
+
+    def post_writer(self, client: httpx.Client, endpoint_url: str, write_queue: WriteQueue):
+        """Handle writing messages to the server.
+
+        Args:
+            client: HTTP client to use.
+            endpoint_url: The endpoint URL to send messages to.
+            write_queue: Queue to read messages from.
+        """
+        try:
+            while True:
+                try:
+                    message = write_queue.get(timeout=DEFAULT_QUEUE_READ_TIMEOUT)
+                    if message is None:
+                        break
+                    if isinstance(message, Exception):
+                        write_queue.put(message)
+                        continue
+
+                    self._send_message(client, endpoint_url, message)
+
+                except queue.Empty:
+                    continue
+        except httpx.ReadError as exc:
+            logger.debug("Post writer shutting down normally: %s", exc)
+        except Exception as exc:
+            logger.exception("Error writing messages")
+            write_queue.put(exc)
+        finally:
+            write_queue.put(None)
+
+    def _wait_for_endpoint(self, status_queue: StatusQueue) -> str:
+        """Wait for the endpoint URL from the status queue.
+
+        Args:
+            status_queue: Queue to read status from.
+
+        Returns:
+            The endpoint URL.
+
+        Raises:
+            ValueError: If endpoint URL is not received or there's an error.
+        """
+        try:
+            status = status_queue.get(timeout=1)
+        except queue.Empty:
+            raise ValueError("failed to get endpoint URL")
+
+        if isinstance(status, _StatusReady):
+            return status.endpoint_url
+        elif isinstance(status, _StatusError):
+            raise status.exc
+        else:
+            raise ValueError("failed to get endpoint URL")
+
+    def connect(
+        self,
+        executor: ThreadPoolExecutor,
+        client: httpx.Client,
+        event_source: EventSource,
+    ) -> tuple[ReadQueue, WriteQueue]:
+        """Establish connection and start worker threads.
+
+        Args:
+            executor: Thread pool executor.
+            client: HTTP client.
+            event_source: SSE event source.
+
+        Returns:
+            Tuple of (read_queue, write_queue).
+        """
+        read_queue: ReadQueue = queue.Queue()
+        write_queue: WriteQueue = queue.Queue()
+        status_queue: StatusQueue = queue.Queue()
+
+        # Start SSE reader thread
+        executor.submit(self.sse_reader, event_source, read_queue, status_queue)
+
+        # Wait for endpoint URL
+        endpoint_url = self._wait_for_endpoint(status_queue)
+        self.endpoint_url = endpoint_url
+
+        # Start post writer thread
+        executor.submit(self.post_writer, client, endpoint_url, write_queue)
+
+        return read_queue, write_queue
+
+
+@contextmanager
+def sse_client(
+    url: str,
+    headers: dict[str, Any] | None = None,
+    timeout: float = 5.0,
+    sse_read_timeout: float = 1 * 60,
+) -> Generator[tuple[ReadQueue, WriteQueue], None, None]:
+    """
+    Client transport for SSE.
+    `sse_read_timeout` determines how long (in seconds) the client will wait for a new
+    event before disconnecting. All other HTTP operations are controlled by `timeout`.
+
+    Args:
+        url: The SSE endpoint URL.
+        headers: Optional headers to include in requests.
+        timeout: HTTP timeout for regular operations.
+        sse_read_timeout: Timeout for SSE read operations.
+
+    Yields:
+        Tuple of (read_queue, write_queue) for message communication.
+    """
+    transport = SSETransport(url, headers, timeout, sse_read_timeout)
+
+    read_queue: ReadQueue | None = None
+    write_queue: WriteQueue | None = None
+
+    executor = ThreadPoolExecutor()
+    try:
+        with create_ssrf_proxy_mcp_http_client(headers=transport.headers) as client:
+            with ssrf_proxy_sse_connect(
+                url, timeout=httpx.Timeout(timeout, read=sse_read_timeout), client=client
+            ) as event_source:
+                event_source.response.raise_for_status()
+
+                read_queue, write_queue = transport.connect(executor, client, event_source)
+
+                yield read_queue, write_queue
+
+    except httpx.HTTPStatusError as exc:
+        if exc.response.status_code == 401:
+            raise MCPAuthError(response=exc.response)
+        raise MCPConnectionError()
+    except Exception:
+        logger.exception("Error connecting to SSE endpoint")
+        raise
+    finally:
+        # Clean up queues
+        if read_queue:
+            read_queue.put(None)
+        if write_queue:
+            write_queue.put(None)
+
+        # Shutdown executor without waiting to prevent hanging
+        executor.shutdown(wait=False)
+
+
+def send_message(http_client: httpx.Client, endpoint_url: str, session_message: SessionMessage):
+    """
+    Send a message to the server using the provided HTTP client.
+
+    Args:
+        http_client: The HTTP client to use for sending
+        endpoint_url: The endpoint URL to send the message to
+        session_message: The message to send
+    """
+    try:
+        response = http_client.post(
+            endpoint_url,
+            json=session_message.message.model_dump(
+                by_alias=True,
+                mode="json",
+                exclude_none=True,
+            ),
+        )
+        response.raise_for_status()
+        logger.debug("Client message sent successfully: %s", response.status_code)
+    except Exception:
+        logger.exception("Error sending message")
+        raise
+
+
+def read_messages(
+    sse_client: SSEClient,
+) -> Generator[SessionMessage | Exception, None, None]:
+    """
+    Read messages from the SSE client.
+
+    Args:
+        sse_client: The SSE client to read from
+
+    Yields:
+        SessionMessage or Exception for each event received
+    """
+    try:
+        for sse in sse_client.events():
+            if sse.event == "message":
+                try:
+                    message = types.JSONRPCMessage.model_validate_json(sse.data)
+                    logger.debug("Received server message: %s", message)
+                    yield SessionMessage(message)
+                except Exception as exc:
+                    logger.exception("Error parsing server message")
+                    yield exc
+            else:
+                logger.warning("Unknown SSE event: %s", sse.event)
+    except Exception as exc:
+        logger.exception("Error reading SSE messages")
+        yield exc

dify/api/core/mcp/client/streamable_client.py

@@ -0,0 +1,485 @@
+"""
+StreamableHTTP Client Transport Module
+
+This module implements the StreamableHTTP transport for MCP clients,
+providing support for HTTP POST requests with optional SSE streaming responses
+and session management.
+"""
+
+import logging
+import queue
+from collections.abc import Callable, Generator
+from concurrent.futures import ThreadPoolExecutor
+from contextlib import contextmanager
+from dataclasses import dataclass
+from datetime import timedelta
+from typing import Any, cast
+
+import httpx
+from httpx_sse import EventSource, ServerSentEvent
+
+from core.mcp.types import (
+    ClientMessageMetadata,
+    ErrorData,
+    JSONRPCError,
+    JSONRPCMessage,
+    JSONRPCNotification,
+    JSONRPCRequest,
+    JSONRPCResponse,
+    RequestId,
+    SessionMessage,
+)
+from core.mcp.utils import create_ssrf_proxy_mcp_http_client, ssrf_proxy_sse_connect
+
+logger = logging.getLogger(__name__)
+
+
+SessionMessageOrError = SessionMessage | Exception | None
+# Queue types with clearer names for their roles
+ServerToClientQueue = queue.Queue[SessionMessageOrError]  # Server to client messages
+ClientToServerQueue = queue.Queue[SessionMessage | None]  # Client to server messages
+GetSessionIdCallback = Callable[[], str | None]
+
+MCP_SESSION_ID = "mcp-session-id"
+LAST_EVENT_ID = "last-event-id"
+CONTENT_TYPE = "content-type"
+ACCEPT = "Accept"
+
+
+JSON = "application/json"
+SSE = "text/event-stream"
+
+DEFAULT_QUEUE_READ_TIMEOUT = 3
+
+
+class StreamableHTTPError(Exception):
+    """Base exception for StreamableHTTP transport errors."""
+
+
+class ResumptionError(StreamableHTTPError):
+    """Raised when resumption request is invalid."""
+
+
+@dataclass
+class RequestContext:
+    """Context for a request operation."""
+
+    client: httpx.Client
+    headers: dict[str, str]
+    session_id: str | None
+    session_message: SessionMessage
+    metadata: ClientMessageMetadata | None
+    server_to_client_queue: ServerToClientQueue  # Renamed for clarity
+    sse_read_timeout: float
+
+
+class StreamableHTTPTransport:
+    """StreamableHTTP client transport implementation."""
+
+    def __init__(
+        self,
+        url: str,
+        headers: dict[str, Any] | None = None,
+        timeout: float | timedelta = 30,
+        sse_read_timeout: float | timedelta = 60 * 5,
+    ):
+        """Initialize the StreamableHTTP transport.
+
+        Args:
+            url: The endpoint URL.
+            headers: Optional headers to include in requests.
+            timeout: HTTP timeout for regular operations.
+            sse_read_timeout: Timeout for SSE read operations.
+        """
+        self.url = url
+        self.headers = headers or {}
+        self.timeout = timeout.total_seconds() if isinstance(timeout, timedelta) else timeout
+        self.sse_read_timeout = (
+            sse_read_timeout.total_seconds() if isinstance(sse_read_timeout, timedelta) else sse_read_timeout
+        )
+        self.session_id: str | None = None
+        self.request_headers = {
+            ACCEPT: f"{JSON}, {SSE}",
+            CONTENT_TYPE: JSON,
+            **self.headers,
+        }
+
+    def _update_headers_with_session(self, base_headers: dict[str, str]) -> dict[str, str]:
+        """Update headers with session ID if available."""
+        headers = base_headers.copy()
+        if self.session_id:
+            headers[MCP_SESSION_ID] = self.session_id
+        return headers
+
+    def _is_initialization_request(self, message: JSONRPCMessage) -> bool:
+        """Check if the message is an initialization request."""
+        return isinstance(message.root, JSONRPCRequest) and message.root.method == "initialize"
+
+    def _is_initialized_notification(self, message: JSONRPCMessage) -> bool:
+        """Check if the message is an initialized notification."""
+        return isinstance(message.root, JSONRPCNotification) and message.root.method == "notifications/initialized"
+
+    def _maybe_extract_session_id_from_response(
+        self,
+        response: httpx.Response,
+    ):
+        """Extract and store session ID from response headers."""
+        new_session_id = response.headers.get(MCP_SESSION_ID)
+        if new_session_id:
+            self.session_id = new_session_id
+            logger.info("Received session ID: %s", self.session_id)
+
+    def _handle_sse_event(
+        self,
+        sse: ServerSentEvent,
+        server_to_client_queue: ServerToClientQueue,
+        original_request_id: RequestId | None = None,
+        resumption_callback: Callable[[str], None] | None = None,
+    ) -> bool:
+        """Handle an SSE event, returning True if the response is complete."""
+        if sse.event == "message":
+            # ping event send by server will be recognized  as a message event with empty data by httpx-sse's SSEDecoder
+            if not sse.data.strip():
+                return False
+
+            try:
+                message = JSONRPCMessage.model_validate_json(sse.data)
+                logger.debug("SSE message: %s", message)
+
+                # If this is a response and we have original_request_id, replace it
+                if original_request_id is not None and isinstance(message.root, JSONRPCResponse | JSONRPCError):
+                    message.root.id = original_request_id
+
+                session_message = SessionMessage(message)
+                # Put message in queue that goes to client
+                server_to_client_queue.put(session_message)
+
+                # Call resumption token callback if we have an ID
+                if sse.id and resumption_callback:
+                    resumption_callback(sse.id)
+
+                # If this is a response or error return True indicating completion
+                # Otherwise, return False to continue listening
+                return isinstance(message.root, JSONRPCResponse | JSONRPCError)
+
+            except Exception as exc:
+                # Put exception in queue that goes to client
+                server_to_client_queue.put(exc)
+                return False
+        elif sse.event == "ping":
+            logger.debug("Received ping event")
+            return False
+        else:
+            logger.warning("Unknown SSE event: %s", sse.event)
+            return False
+
+    def handle_get_stream(
+        self,
+        client: httpx.Client,
+        server_to_client_queue: ServerToClientQueue,
+    ):
+        """Handle GET stream for server-initiated messages."""
+        try:
+            if not self.session_id:
+                return
+
+            headers = self._update_headers_with_session(self.request_headers)
+
+            with ssrf_proxy_sse_connect(
+                self.url,
+                headers=headers,
+                timeout=httpx.Timeout(self.timeout, read=self.sse_read_timeout),
+                client=client,
+                method="GET",
+            ) as event_source:
+                event_source.response.raise_for_status()
+                logger.debug("GET SSE connection established")
+
+                for sse in event_source.iter_sse():
+                    self._handle_sse_event(sse, server_to_client_queue)
+
+        except Exception as exc:
+            logger.debug("GET stream error (non-fatal): %s", exc)
+
+    def _handle_resumption_request(self, ctx: RequestContext):
+        """Handle a resumption request using GET with SSE."""
+        headers = self._update_headers_with_session(ctx.headers)
+        if ctx.metadata and ctx.metadata.resumption_token:
+            headers[LAST_EVENT_ID] = ctx.metadata.resumption_token
+        else:
+            raise ResumptionError("Resumption request requires a resumption token")
+
+        # Extract original request ID to map responses
+        original_request_id = None
+        if isinstance(ctx.session_message.message.root, JSONRPCRequest):
+            original_request_id = ctx.session_message.message.root.id
+
+        with ssrf_proxy_sse_connect(
+            self.url,
+            headers=headers,
+            timeout=httpx.Timeout(self.timeout, read=self.sse_read_timeout),
+            client=ctx.client,
+            method="GET",
+        ) as event_source:
+            event_source.response.raise_for_status()
+            logger.debug("Resumption GET SSE connection established")
+
+            for sse in event_source.iter_sse():
+                is_complete = self._handle_sse_event(
+                    sse,
+                    ctx.server_to_client_queue,
+                    original_request_id,
+                    ctx.metadata.on_resumption_token_update if ctx.metadata else None,
+                )
+                if is_complete:
+                    break
+
+    def _handle_post_request(self, ctx: RequestContext):
+        """Handle a POST request with response processing."""
+        headers = self._update_headers_with_session(ctx.headers)
+        message = ctx.session_message.message
+        is_initialization = self._is_initialization_request(message)
+
+        with ctx.client.stream(
+            "POST",
+            self.url,
+            json=message.model_dump(by_alias=True, mode="json", exclude_none=True),
+            headers=headers,
+        ) as response:
+            if response.status_code == 202:
+                logger.debug("Received 202 Accepted")
+                return
+
+            if response.status_code == 204:
+                logger.debug("Received 204 No Content")
+                return
+
+            if response.status_code == 404:
+                if isinstance(message.root, JSONRPCRequest):
+                    self._send_session_terminated_error(
+                        ctx.server_to_client_queue,
+                        message.root.id,
+                    )
+                return
+
+            response.raise_for_status()
+            if is_initialization:
+                self._maybe_extract_session_id_from_response(response)
+
+            content_type = cast(str, response.headers.get(CONTENT_TYPE, "").lower())
+
+            if content_type.startswith(JSON):
+                self._handle_json_response(response, ctx.server_to_client_queue)
+            elif content_type.startswith(SSE):
+                self._handle_sse_response(response, ctx)
+            else:
+                self._handle_unexpected_content_type(
+                    content_type,
+                    ctx.server_to_client_queue,
+                )
+
+    def _handle_json_response(
+        self,
+        response: httpx.Response,
+        server_to_client_queue: ServerToClientQueue,
+    ):
+        """Handle JSON response from the server."""
+        try:
+            content = response.read()
+            message = JSONRPCMessage.model_validate_json(content)
+            session_message = SessionMessage(message)
+            server_to_client_queue.put(session_message)
+        except Exception as exc:
+            server_to_client_queue.put(exc)
+
+    def _handle_sse_response(self, response: httpx.Response, ctx: RequestContext):
+        """Handle SSE response from the server."""
+        try:
+            event_source = EventSource(response)
+            for sse in event_source.iter_sse():
+                is_complete = self._handle_sse_event(
+                    sse,
+                    ctx.server_to_client_queue,
+                    resumption_callback=(ctx.metadata.on_resumption_token_update if ctx.metadata else None),
+                )
+                if is_complete:
+                    break
+        except Exception as e:
+            ctx.server_to_client_queue.put(e)
+
+    def _handle_unexpected_content_type(
+        self,
+        content_type: str,
+        server_to_client_queue: ServerToClientQueue,
+    ):
+        """Handle unexpected content type in response."""
+        error_msg = f"Unexpected content type: {content_type}"
+        logger.error(error_msg)
+        server_to_client_queue.put(ValueError(error_msg))
+
+    def _send_session_terminated_error(
+        self,
+        server_to_client_queue: ServerToClientQueue,
+        request_id: RequestId,
+    ):
+        """Send a session terminated error response."""
+        jsonrpc_error = JSONRPCError(
+            jsonrpc="2.0",
+            id=request_id,
+            error=ErrorData(code=32600, message="Session terminated by server"),
+        )
+        session_message = SessionMessage(JSONRPCMessage(jsonrpc_error))
+        server_to_client_queue.put(session_message)
+
+    def post_writer(
+        self,
+        client: httpx.Client,
+        client_to_server_queue: ClientToServerQueue,
+        server_to_client_queue: ServerToClientQueue,
+        start_get_stream: Callable[[], None],
+    ):
+        """Handle writing requests to the server.
+
+        This method processes messages from the client_to_server_queue and sends them to the server.
+        Responses are written to the server_to_client_queue.
+        """
+        while True:
+            try:
+                # Read message from client queue with timeout to check stop_event periodically
+                session_message = client_to_server_queue.get(timeout=DEFAULT_QUEUE_READ_TIMEOUT)
+                if session_message is None:
+                    break
+
+                message = session_message.message
+                metadata = (
+                    session_message.metadata if isinstance(session_message.metadata, ClientMessageMetadata) else None
+                )
+
+                # Check if this is a resumption request
+                is_resumption = bool(metadata and metadata.resumption_token)
+
+                logger.debug("Sending client message: %s", message)
+
+                # Handle initialized notification
+                if self._is_initialized_notification(message):
+                    start_get_stream()
+
+                ctx = RequestContext(
+                    client=client,
+                    headers=self.request_headers,
+                    session_id=self.session_id,
+                    session_message=session_message,
+                    metadata=metadata,
+                    server_to_client_queue=server_to_client_queue,  # Queue to write responses to client
+                    sse_read_timeout=self.sse_read_timeout,
+                )
+
+                if is_resumption:
+                    self._handle_resumption_request(ctx)
+                else:
+                    self._handle_post_request(ctx)
+            except queue.Empty:
+                continue
+            except Exception as exc:
+                server_to_client_queue.put(exc)
+
+    def terminate_session(self, client: httpx.Client):
+        """Terminate the session by sending a DELETE request."""
+        if not self.session_id:
+            return
+
+        try:
+            headers = self._update_headers_with_session(self.request_headers)
+            response = client.delete(self.url, headers=headers)
+
+            if response.status_code == 405:
+                logger.debug("Server does not allow session termination")
+            elif response.status_code != 200:
+                logger.warning("Session termination failed: %s", response.status_code)
+        except Exception as exc:
+            logger.warning("Session termination failed: %s", exc)
+
+    def get_session_id(self) -> str | None:
+        """Get the current session ID."""
+        return self.session_id
+
+
+@contextmanager
+def streamablehttp_client(
+    url: str,
+    headers: dict[str, Any] | None = None,
+    timeout: float | timedelta = 30,
+    sse_read_timeout: float | timedelta = 60 * 5,
+    terminate_on_close: bool = True,
+) -> Generator[
+    tuple[
+        ServerToClientQueue,  # Queue for receiving messages FROM server
+        ClientToServerQueue,  # Queue for sending messages TO server
+        GetSessionIdCallback,
+    ],
+    None,
+    None,
+]:
+    """
+    Client transport for StreamableHTTP.
+
+    `sse_read_timeout` determines how long (in seconds) the client will wait for a new
+    event before disconnecting. All other HTTP operations are controlled by `timeout`.
+
+    Yields:
+        Tuple containing:
+            - server_to_client_queue: Queue for reading messages FROM the server
+            - client_to_server_queue: Queue for sending messages TO the server
+            - get_session_id_callback: Function to retrieve the current session ID
+    """
+    transport = StreamableHTTPTransport(url, headers, timeout, sse_read_timeout)
+
+    # Create queues with clear directional meaning
+    server_to_client_queue: ServerToClientQueue = queue.Queue()  # For messages FROM server TO client
+    client_to_server_queue: ClientToServerQueue = queue.Queue()  # For messages FROM client TO server
+
+    executor = ThreadPoolExecutor(max_workers=2)
+    try:
+        with create_ssrf_proxy_mcp_http_client(
+            headers=transport.request_headers,
+            timeout=httpx.Timeout(transport.timeout, read=transport.sse_read_timeout),
+        ) as client:
+            # Define callbacks that need access to thread pool
+            def start_get_stream():
+                """Start a worker thread to handle server-initiated messages."""
+                executor.submit(transport.handle_get_stream, client, server_to_client_queue)
+
+            # Start the post_writer worker thread
+            executor.submit(
+                transport.post_writer,
+                client,
+                client_to_server_queue,  # Queue for messages FROM client TO server
+                server_to_client_queue,  # Queue for messages FROM server TO client
+                start_get_stream,
+            )
+
+            try:
+                yield (
+                    server_to_client_queue,  # Queue for receiving messages FROM server
+                    client_to_server_queue,  # Queue for sending messages TO server
+                    transport.get_session_id,
+                )
+            finally:
+                if transport.session_id and terminate_on_close:
+                    transport.terminate_session(client)
+
+                # Signal threads to stop
+                client_to_server_queue.put(None)
+    finally:
+        # Clear any remaining items and add None sentinel to unblock any waiting threads
+        try:
+            while not client_to_server_queue.empty():
+                client_to_server_queue.get_nowait()
+        except queue.Empty:
+            pass
+
+        client_to_server_queue.put(None)
+        server_to_client_queue.put(None)
+
+        # Shutdown executor without waiting to prevent hanging
+        executor.shutdown(wait=False)