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A Podcast URL Scheme

Posted by Padraig on Feb 13, 2018

Mark Steadman:

Subscribing to a podcast should be as easy as sending an email, if not easier. In an ideal world, you find a podcast you like, somewhere on the web, click “Subscribe” and are redirected to your podcast app of choice, which shows the artwork, description and list of episodes (just as if you’d tapped a search result within the app). You tap the “Subscribe” button in your app, and you’re done.

The suggested solution is a podto: scheme. The scheme is the http:part of a url; the email scheme is mailto: for example. Tapping scheme links usually makes the OS open whatever app is registered with that scheme and sends the text that comes after the colon to that app.

Adding support for this scheme to Castro (or any other podcast app) is trivial, but there are problems with the concept:

  • There’s already a pcast: scheme but Apple associated it with Apple Podcasts app in 2012, so it always opens to Apple Podcasts. This is a reasonable default, but it can’t be changed to third party app, because iOS doesn’t give users the ability to change it.
  • Users could have many podcast apps installed. If they all supported this scheme, podto: will open one of them, but users won’t be able to choose which.
  • If it caught on, Apple would probably add support for it to Apple Podcasts and we’d all be back at square one.
  • Tapping it on a system that doesn’t have a podto: app installed would cause a uselessly vague error for the user along the lines of “Safari cannot open the page because the address is invalid.” That’s more confusing for the user than the alternatives.

Our solution to this problem is our — <a href=""></a> links. To link to shows in Castro, podcasters only need to know their own iTunes ID, not our internal id for their podcast. Overcast and Pocket Casts also have URLs that can understand iTunes IDs.

The Castro link takes you to a page with buttons to subscribe directly in the major iOS apps. It’s not perfect, but it works today and doesn’t require the industry to change before it can be useful. Any other podcast app maker can build a version of this too, by taking the iTunes ID and then using the lookup endpoint to get the RSS feed.

Another worthwhile alternative that works today is the Podlove Subscribebutton.

The best answer here is for Apple to start allowing iOS users to do what Windows and Mac users have done for years. Let us choose our own default apps to handle the various scheme links. At present, even deleting a first party app doesn’t relinquish the association; instead the user is prompted to reinstall the deleted first party app.

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