aiohttp-sse-client2

Warnings

• breaking Python version support has changed between major versions. Version 0.2.0 dropped support for Python 3.5, and version 0.3.0 dropped support for Python 3.6.
  Fix: Ensure your environment uses Python 3.7 or newer for version 0.3.0, or Python 3.6 or newer for 0.2.x releases.
• gotcha The underlying `aiohttp.ClientSession` used by `EventSource` has a default total timeout (typically 5 minutes). For long-lived SSE connections, this can lead to `asyncio.TimeoutError` or `ClientOSError: [Errno 104] Connection reset by peer` even with server-side keep-alives.
  Fix: When initializing `EventSource`, pass a custom `aiohttp.ClientSession` with an explicitly configured timeout, typically `aiohttp.ClientTimeout(total=None)` for indefinite connections, or a sufficiently large value. Example: `session = aiohttp.ClientSession(timeout=aiohttp.ClientTimeout(total=None))` then `sse_client.EventSource(url, session=session)`.
• gotcha This library is a fork of `aiohttp-sse-client`, and its long-term maintenance is conditional: 'The fork will be retired if the upstream package comes back alive.'
  Fix: Be aware of the project's fork status. Monitor the GitHub repository for updates regarding its maintenance and consider the implications for long-term project stability if the original `aiohttp-sse-client` project becomes active again.
• gotcha Asynchronous network operations are inherently prone to disconnections. The quickstart example explicitly includes `except ConnectionError: pass`, indicating that connection failures are common and client applications should implement robust error handling and reconnection logic.
  Fix: Implement comprehensive `try...except` blocks around the event iteration to gracefully handle `ConnectionError`, `asyncio.TimeoutError`, and other network-related exceptions. Consider adding retry mechanisms with exponential backoff for resilience.

Install

• pip install aiohttp-sse-client2 Install stable release

Imports

• EventSource

  from aiohttp_sse_client2 import client as sse_client
  # then use sse_client.EventSource

Quickstart

This quickstart demonstrates connecting to a public SSE stream and iterating over incoming events. It also includes basic error handling for common connection issues. For long-running connections, consider configuring `aiohttp.ClientTimeout` explicitly.

import asyncio
from aiohttp_sse_client2 import client as sse_client

async def main():
    # Replace with your SSE endpoint
    sse_url = "https://stream.wikimedia.org/v2/stream/recentchange"
    
    # It's recommended to pass an aiohttp.ClientSession with a custom timeout
    # if long-lived connections are expected (e.g., timeout=aiohttp.ClientTimeout(total=None))
    # For this quickstart, we'll use the default behavior.
    
    async with sse_client.EventSource(sse_url) as event_source:
        try:
            async for event in event_source:
                print(f"Received event: {event.id} - {event.event} - {event.data}")
        except ConnectionError:
            print("Connection closed unexpectedly or failed to establish.")
        except asyncio.TimeoutError:
            print("Connection timed out.")
        except Exception as e:
            print(f"An unexpected error occurred: {e}")

if __name__ == "__main__":
    asyncio.run(main())