Mastodon, X & Co.: Automatic posts from Wordpress, RSS etc.
You want to automatically fill multiple social media channels with content from multiple sources? No problem!

There are quite a few tools and services under the label social media scheduler, which you can use to plan and send X, Facebook or Mastodon postings. If it also mastodon and please free should be, you can do it with dlvr.it try: Easy to use, decent dashboard, many services supported - but with limitations in the free version.
The Dlvr.it service
Dlvr.it (short for "deliver it"/"liefere es") works very simply: You connect your Dlvr.it account with one of yours social media accounts, For example, your Mastodon profile - this can be done at the push of a button and authentication, as usual. Also supported: Facebook, LinkedIn, Instagram, Reddit and more. Then you lay Content Sources at. This can be, for example, RSS feeds, Wordpress pages, YouTube channels or Etsy pages. As soon as new content appears in the sources, it is automatically published in the linked social media channels.
The limitations Free version: 2 social media channels, 50 posts per month, 3 sources, 3 hour post delay. Of course, this is not enough for aspiring influencers. But if you just want to publish a few blog posts or new shop products on Twitter and Facebook every now and then, that might be enough.
In the chargeable Versions are then available for USD 10,79 or USD 29,95 per month, faster updates, any number of posts, a scheduler and so on. You can find the overview here.
Use Dlvr.it
As I said, the configuration is trivial. Nevertheless, here is the whole workflow in the picture. After registering, you can Social Media Accounts link by your under Socials click on the corresponding button:

Then select the desired service:

Confirms authorization:

Then it's up to them Feeds/Sources: First select the source type or use the feeds search:

For example, you can use the RSS Feed use any website:

In the second step, you specify the name, when it should be posted and whether something should be published initially:

Finally, you determine which socials the feed should be published on:

Our Tutonaut contributions, for example, will also automatically be uploaded from today my mastodon canal.
