Installation

$ pip install sseclient-py

Usage

import requests
import sseclient

url = "https://example.com/events"
with requests.get(
    url,
    headers={"Accept": "text/event-stream"},
    stream=True,
    timeout=(3.05, 60),
) as response:
    response.raise_for_status()
    for event in sseclient.SSEClient(response).events():
        print(event.id, event.event, event.data)

The timeout is a connect/read timeout, not a limit on the whole stream. Adjust the read timeout to allow for your server’s keep-alive interval.

Other HTTP clients

Pass the client’s byte stream to SSEClient:

import httpx
import urllib3

# urllib3
http = urllib3.PoolManager()
response = http.request("GET", url, preload_content=False)
client = sseclient.SSEClient(response.stream())

# httpx
with httpx.stream("GET", url) as response:
    client = sseclient.SSEClient(response.iter_bytes())
    for event in client.events():
        print(event.data)

Reconnecting

Manage connections and retries in your application. Reconnect when events() ends or the HTTP client raises a connection or read-timeout error. Use a delay or backoff between attempts.

Resuming depends on the server. When event.id is not None, remember that ID, including an empty string (which clears it). Send a non-empty remembered ID in the next request’s Last-Event-ID header. ID-only updates are not exposed by this parser; duplicate-free delivery is not guaranteed.

The yielded events have id, event, data and retry attributes. Comments and events without data are ignored.

Resources

• SSE specification

• PyPI

• Source and issues