Python SSE Client

This is a Python client library for iterating over http Server Sent Event (SSE) streams (also known as EventSource, after the name of the Javascript interface inside browsers). The SSEClient class accepts a url on init, and is then an iterator over messages coming from the server.


Use pip:

pip install sseclient


from sseclient import SSEClient

messages = SSEClient('')
for msg in messages:

Each message object will have a 'data' attribute, as well as optional 'event', 'id', and 'retry' attributes.

Optional init parameters:

  • last_id: If provided, this parameter will be sent to the server to tell it to return only messages more recent than this ID.
  • retry: Number of milliseconds to wait after disconnects before attempting to reconnect. The server may change this by including a 'retry' line in a message. Retries are handled automatically by the SSEClient object.

You may also provide any additional keyword arguments supported by the Requests library, such as a 'headers' dict and a (username, password) tuple for 'auth'.


Simply run the tests with:

$ python test
=================== test session starts ====================
platform darwin -- Python 3.4.3 -- py-1.4.30 -- pytest-2.7.2
rootdir: /Users/jaraco/Dropbox/code/public/sseclient, inifile:
plugins: backports.unittest-mock
collected 11 items ...........

================ 11 passed in 0.12 seconds =================

There are a couple TODO items in the code for getting the implementation completely in line with the finer points of the SSE spec.

Additional Resources