This is an important step toward a more interoperable "fediverse" — that larger, decentralized network of social media applications, including Mastodon, Bluesky, and others. The integration allows users on Mastodon, run on the ActivityPub protocol, and on those run on the AT Protocol by Bluesky, to now very easily follow people on other networks, see what they are posting, like those posts, reply and repost them.

And those same people will be able to see the posts of others, too.

That technology is Bridgy Fed, one of the efforts aimed at connecting the fediverse with the web, Bluesky and perhaps later on other networks such as Nostr.

Given the sale of Twitter to Elon Musk last year, who rebranded it to X, there has been an uptick of new interest in decentralized social media. Apps like Mastodon very quickly gained popularity following Twitter's acquisition news, as users sought to get a glimpse of what a network without a central authority might look like. Meanwhile, the Bluesky not only raised a seed round but also grew into more than 5.7 million users after it went public earlier this year, having originally being incubated within Twitter.

Other decentralized social media networks are finding footing of their own, too, like blockchain-based Farcaster, which just last month closed on $150 million in funding from Paradigm, a16z crypto, Haun Ventures, USV and others.

There's just one problem these networks face in gaining traction against a rival like X or Meta's Threads: Their users couldn't talk to each other.

While both Mastodon and Bluesky are decentralized efforts on social media, they're based upon different underlying protocols. This means a Mastodon user can interact with others who post elsewhere on the fediverse-that is, other apps that make use of the older ActivityPub social networking protocol. But they couldn't interact with people who posted on Bluesky, as it makes use of the newer AT Protocol to operate.

Software developer Ryan Barrett worked to solve this problem with Bridgy Fed, a social networking bridge that connects fediverse users to those on Bluesky and vice versa.

The issue was contentious right from the planned opt-out nature of the bridge, but Barrett took the community feedback well by making both sides opt-in for now.

Of course, that could change in the future to be opt-out only for Bluesky users. "The norms and expectations there are slightly different than in the fediverse," he said to TechCrunch.

Bridgy Fed self-soft-launched in mid-April and's been fully launched over the last month. It is now just one of several efforts to bridge networks within the fediverse, in addition to Sasquatch, pinhole, RSS Parrot, Mostr, and SkyBridge, though many are not as fully bidirectional as Bridgy is.
How to use Bridgy Fed
Using Bridgy Fed is pretty easy. It will only work with public accounts and public posts, so you never have to worry about your private or followers-only posts being duplicated elsewhere.

To bridge an account from the fediverse to Bluesky, you just follow the Mastodon account @bsky.brid.gy@bsky.brid.gy. The account will follow you back. You'll then automatically have a new, bridged account available to Bluesky users under your fediverse/Mastodon handle (where the second @ is now a dot) followed by "ap.brid.gy."

For example, if my Mastodon account is @sarahp@mastodon.social, then my bridged account is @sarahp.mastodon.social.ap.brid.gy.

(OK, I know, it's lots of letters, but it works!)

On the flip side, if you want to link your Bluesky account with the fediverse, you'll follow the @ap.brid.gy account on Bluesky. You'll get a fediver-sied version of your Bluesky account. In this case, the format follows as @[handle]@bsky.brid.gy.

So if my Bluesky account is @sarahp@bsky.social, then my bridged account is @sarahp.bsky.social@bsky.brid.gy. It will also be tagged as an "automated" account on Mastodon so people know it's a bridged account.

Anything from your Bluesky account that interacts with fediverse users will be bridged, including replies, @-mentions, likes, reports, and, if you have fediverse followers, your own Bluesky posts. The reverse works the same way.

Clearly, this isn't a cross-posting, where you post once using software that automatically publishes it across all connected accounts. It is, rather a mirror setting for your feed on the other platform. This would allow you to reach more people because you'd be able to engage with people on another social network.

The fediverse-to-Bluesky bridge (and vice versa) are still very early beta and you should expect to encounter issues, bugs, downtime and other problems for now.

Barrett has more in store for Bridgy Fed, including deploying a prompt to make it discoverable. "When you try to follow someone who isn't yet bridged, it will send them a DM to ask them to opt in. I'm waiting on Bluesky's upcoming OAuth support for that," he adds.

This bridge currently connects to fediverse servers such as Mastodon, Friendica, Misskey, PeerTube, Hubzilla and many others, plus Bluesky and your own website. Later, it'll add Nostr support as a downstream bridge too - a decentralized social service now favored by Twitter co-founder and former CEO Jack Dorsey.