Since it was founded in March 2006, there has been only one type of post possible on Twitter: a tweet. But starting today, the 280-character post is being joined by an ephemeral South American cousin: the fleet.

That’s what Twitter is calling these new, more fleeting tweets — posts that appear in a separate timeline above the main timeline for 24 hours before disappearing. In other words, yes, Twitter is finally doing Snapchat Stories, and the implementation looks nearly identical to Instagram’s version of the feature.

“Twitter is for having conversations about what you care about,” Mo Aladham, a Twitter group product manager, said in a blog post. “But, some of you tell us that you’re uncomfortable to tweet because tweets are public, feel permanent, and have public counts (retweets and likes). We want to make it possible for you to have conversations in new ways with less pressure and more control, beyond tweets and direct messages. That’s why starting today in Brazil, we’re testing fleets, a new way to start conversations from your fleeting thoughts.”

To create a fleet, you’ll tap a plus button that appears on a new home row of ephemeral posts on top of your home timeline. From there, you can type up to 280 characters of text or add photos, GIFs, or videos. Once you hit post, your fleet will appear in a lightly ranked side-scrolling row of posts. Fleets from people you follow and who follow you back will appear first, with the most recently posted visible first. From there, you’ll see posts from other accounts that you follow.

You cannot like or retweet a fleet.

You can respond to fleets with reaction emoji similar to those that were recently introduced in direct messages. You can also respond with text, which will open up a DM with the person you’re messaging.

Fleets, like stories everywhere, disappear after 24 hours.

I know what you're thinking: “THIS SOUNDS A LOT LIKE STORIES!”. Yes, there are many similarities with the Stories format that will feel familiar to people. There are also a few intentional differences to make the experience more focused on sharing and seeing people’s thoughts. pic.twitter.com/OaGYZpChcN — Kayvon Beykpour (@kayvz) March 4, 2020

Twitter has reportedly been working on ephemeral posts for more than a year. In October, the company’s head of product, Kayvon Beykpour, told The Verge that he was interested in exploring the concept:

I view that as another dimension that is really important for some customers: for some specific set of circumstances where you want to talk to people, but you’re not quite sure you want it to last forever yet. And so I think as a dimension to focus on, as a specific customer problem, absolutely, I’m very interested in exploring how we might give customers more control.

Dorky as the name may be, fleets represent an opportunity for Twitter to gain some of the ground it has lost to Instagram, Snapchat, and other social platforms over the years as ephemeral messaging has become more popular. It’s not just that the tweets will disappear automatically (although that helps); it’s that stories seem to encourage a different kind of sharing — more disposable, more casual, more intimate. The main feed is for polished public performance, and stories are more about idle chitchat.

At least, that’s how it has played out elsewhere. Twitter will surely bring its own wrinkles to the format, assuming that fleets roll out more broadly.

I assume they will. Fleets are currently being tested internally among employees in addition to the test in Brazil. And last month, Twitter bought Chroma Labs, a seven-person startup founded by former Facebook and Instagram employees that make a tool for creating ephemeral stories.

Anyway, fleets! This is real life.