"OPEN packet not returned by server"

[brndnsy]

When attempting to establish a WebSocket connection using the MetaApi Python SDK, I encountered a recurring error during the initial handshake process. The error message is:
OPEN packet not returned by server

This error is thrown by the underlying Engine.IO client (specifically during the polling transport phase) and prevents the connection from being successfully established. The error appears repeatedly when trying to connect to multiple MetaApi endpoints (e.g., https://mt-client-api-v1.london-a.agiliumtrade.ai and https://mt-client-api-v1.london-b.agiliumtrade.ai).

The issue occurs during the initial handshake—before any broker-specific actions are taken—indicating that the expected handshake (OPEN) packet from the server is not being received. This suggests the problem might lie with the MetaApi server or its compatibility with the current SDK/Engine.IO version.

Here's more of the error code:

raise exceptions.ConnectionError(\nengineio.exceptions.ConnectionError: OPEN packet not returned by server\n"}
[2025-02-05T08:29:38.493015] Connecting MetaApi websocket client to the MetaApi server via https://mt-client-api-v1.london-a.agiliumtrade.ai shared server.
[2025-02-05T08:29:38.504624] london:1: MetaApi websocket client connection error {"name": "str", "message": "OPEN packet not returned by server", "trace": "Traceback (most recent call last):\n  File \"/Users/locus/miniforge3/envs/py311/lib/python3.11/site-packages/socketio/async_client.py\", line 149, in connect\n    await self.eio.connect(real_url, headers=real_headers,\n  File \"/Users/locus/miniforge3/envs/py311/lib/python3.11/site-packages/engineio/async_client.py\", line 130, in connect\n    return await getattr(self, '_connect_' + self.transports[0])

[sizbus]

Hello,
I used metaAPI some weeks ago, and I just try to use it again. But I have encountered error as below.
Code is same and metaAPI was version-raised three weeks ago.

Waiting for API server to connect to broker (may take couple of minutes) Waiting for SDK to synchronize to terminal state (may take some time depending on your history size) [2025-02-18T00:47:09.519997] Connecting MetaApi websocket client to the MetaApi server via https://mt-client-api-v1.new-york-a.agiliumtrade.ai shared server. aiohttp not installed -- cannot make HTTP requests! [2025-02-18T00:47:09.520701] Connecting MetaApi websocket client to the MetaApi server via https://mt-client-api-v1.new-york-b.agiliumtrade.ai shared server. aiohttp not installed -- cannot make HTTP requests!

[brndnsy]

I fixed the issue by updating packages according to Stackoverflow: https://stackoverflow.com/questions/66809068/python-socketio-open-packet-not-returned-by-the-server

Your issue says "aiohttp not installed" so try pip installing that.

[sizbus]

I was successfully using my own app including 'metaAPI'. 'aiohttp' was also installed before.
Anyway, thanks for your answer.