Updating the SO feeds to use PubSubHubbub is easy, would accelerate the propagation of updates and will save bandwith for the publisher and subscribers


One of the steps are:

In RSS add right after the opening "channel" tag:

<atom:link rel="hub" href="http://pubsubhubbub.appspot.com"/>

In Atom inside the "feed" tag:

<link rel="hub" href="http://pubsubhubbub.appspot.com"/>
  • 1
    If I get this correctly, you are suggesting to push the stuff instead of pulling it. Is that right? Commented Aug 24, 2009 at 13:12
  • Yeah, I am suggesting to have the push option, without breaking any existing functionality
    – Jader Dias
    Commented Aug 24, 2009 at 17:04
  • Then I have to upvote you. Commented Aug 25, 2009 at 7:03
  • Upvoting this as well. PubSubHubbub on SO would be really nice.
    – sork
    Commented May 27, 2010 at 9:41
  • How does this affect existing RSS feeds that users already have? What about subscribing to new ones? Would the usage be identical to what we already have?
    – devinb
    Commented Aug 12, 2010 at 13:44

3 Answers 3


This would be wonderful! I actually offered Jeff (who pointed me to the topic) and Joel a few weeks ago to host a hub for them.

The Appspot hub is great, but it was built as a "demo" initially, even though it is now used by most of Google's properties.

However, I think the Superfeedr hosted hubs offer a few other cool features, like export of the data (that that appspot hub doesn't have), analytics, and a few other neat features that we're announcing soon. We already host hubs for the folks at Tumblr, Posterous, Gawker Media, HuffPost and several other publishers (big or small). I'd love to count the SO feeds as well!

Jader, there are actually 2 steps to making feeds realtime.

  • The first one (discovery) is roughly what you describe. (It's important for RSS feeds to add a link, with rel="self").

  • The 2nd step is to ping the hub whenever a feed is updated. The hub will then fetch the feed, make diffs (to see the old vs. new entries), and notify subscribers (obviously!).

All in all, no matter how you decide to do it (Superfeedr or Google), I think this is a great step for the community and that will allow people to build interesting clients that can consumer the SO data out of SO. (who said IM bot?)


UPDATE It's now been over a year publishing data to pubsubhubbub and we haven't really seen much use at this point and are considering closing this service. Stats show that we are being pinged by the hub but we have no visibility as far as who is using the feeds provided by the hub.

How many of you are actually using this service and would hate to see it go?

We now support pubsubhubbub on single question feeds via http://pubsubhubbub.appspot.com on stackoverflow.com and meta.stackoverflow.com only at the moment. We will be working to make other feeds available in the future (tags, tag combinations, etc).

I threw together a really quick app to demo the real-time nature of pubsubhubbub here:


Just paste the question feed url located at the bottom of every question and click subscribe - wait for a confirmation and then answer a question. All future answers posted will automatically be shown as they come in.

Single tag feeds are now supported

Check: https://stackoverflow.com/feeds/tag/java

  • uh... I don't think the latest SO question has been asked two hours ago.
    – badp
    Commented Dec 2, 2011 at 22:44
  • @badp I am not sure what you're referring to here Commented Dec 2, 2011 at 22:53
  • er... When I clicked the link yesterday there was a list of Java question, the latest being 2 hours old. Now I see some kind of feed reader interface instead. I'm confused; then again I really didn't understand what the hell PubSubHubBub means for subscribers, without understand it's really a feature of Google Reader and possibly other feed readers, so subscribers really don't have anything to do to get the benefits.
    – badp
    Commented Dec 3, 2011 at 6:09
  • HUGE! Thanks a lot Geoff! Feel free to check out superfeedr.com if you ever want to have your very own hub + analytics + export :) Commented Dec 3, 2011 at 14:03
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    @GeoffDalgas A separate question might get more visibility.
    – Adam Lear StaffMod
    Commented Mar 14, 2013 at 1:20
  • Possibly - we'll see what this turns up first. Commented Mar 14, 2013 at 1:26

I would really love to see Pubsubhubbub-Support (every time a have to type this I think I got it wrong o_O ) on SO, SV and SU.

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