> For the complete documentation index, see [llms.txt](https://modfin.gitbook.io/mfn-integration-guide/-MbDBLBpI3LuyvwyWLVw/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://modfin.gitbook.io/mfn-integration-guide/-MbDBLBpI3LuyvwyWLVw/api/websub.md).

# WebSub

The v1 API also acts as an extended [WebSub](https://www.w3.org/TR/websub/) hub that can be used for setting up WebSub subscriptions to feed change events. The most typical event is when a new release is published (added to the feed), but there is also optional events that you can subscribe to for when a release is updated or hidden/deleted.

WebSub is a protocol for programmatically setting up webhooks/posthooks from your side. For example our wordpress plugin uses WebSub for setting up its subscription. Optionally we can add posthooks/subscriptions manually.

## Usage overview

* Required: setup a HTTP/HTTPS [endpoint](/mfn-integration-guide/-MbDBLBpI3LuyvwyWLVw/api/websub/endpoint.md) on your server that you would like to get a POST request when a new press release is published
* Alternatively:
  * We can add/setup the subscription endpoint in our system manually if you send us the endpoint/callback URL.
  * Use WebSub to setup the [subscription](/mfn-integration-guide/-MbDBLBpI3LuyvwyWLVw/api/websub/subscribe.md) in our system. This requires that the endpoint handles a WebSub challenge GET request as well. 
* Optional: If your system can handle extended events (`hub.ext.event`) for when an existing press release in the feed is updated (PUT / DELETE) this should also be implemented in your [endpoint](/mfn-integration-guide/-MbDBLBpI3LuyvwyWLVw/api/websub/endpoint.md).
* Optional: Your endpoint can also optionally implement our [Ping extension](/mfn-integration-guide/-MbDBLBpI3LuyvwyWLVw/api/websub/ping.md) (`hub.ext.ping`) if you would like us to ping your endpoint periodically to make sure that it stills works. 


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