Taylor Singletary posted to the Developers blog that the API v1 retirement was complete. The first paragraph is hardly consoling to anybody trying to fix the failing component on their website.
Today, we are retiring API v1 and fully transitioning to API v1.1. Given the array of blackout tests, blogposts,Tweets and other updates, this should (hopefully) not be a surprise. Before I get into the slew of resources available for you, let me first say thank you for your cooperation over the last several months.
While individuals that make such widgets or apps based on Twitter should certainly be paying attention to the Twitter development blog, individuals using those widgets extends far beyond the tech savvy. A number of self-hosted WordPress sites are affected by the change using old plugins that have not been updated. Even the popular WordPress plugin Jetpack had a Twitter widget that was replaced in early May with a ‘Twitter Timeline’ widget but users still using the old style will be affected by the change and need to implement the new widget.
WordPress users might use other working widgets that specify compatibility with Twitter API v1.1 such as Twitter Widget Pro. With the new API v1.1 requirements, users will need to create an application on Twitter and provide the consumer secret and key to their widgets in order for them to work. I’m not sure why Twitter requires using OAuth in order to read from a publicly accessible website.
Alternatively, some people might look to be getting away from relying on other developers and their widgets at all. You can go straight to Twitter and create a Timeline widget and then use the provided widget ID to make an embedded timeline.