What Bluesky Labelers Are and How Subscribing to One Works

The services that tag Bluesky posts and accounts with warnings such as spam, porn or a custom label are bluesky labelers, and the Bluesky app lets you subscribe to the ones you trust and choose whether each label hides, warns or does nothing. The app describes labels in one line: "Labels are annotations on users and content. They can be used to hide, warn, and categorize the network." Subscribe to the labelers whose judgement you share, and remember that their labels filter only your own view.

What is a labeler on Bluesky?

A labeler on Bluesky is an account that runs a labeling service and publishes labels about other content. Bluesky's 2024 post on its moderation architecture puts it plainly: "Moderation is done by a dedicated service called the Labeler (or 'Labeling service')." Labels can target a single post, an account, a profile, a list or a feed.

An ordinary account becomes a labeler by publishing an app.bsky.labeler.service record in its repository. That record lists the label values the service uses and the report types it accepts. The labels themselves live elsewhere. Bluesky's developer guide says: "The labels are not published on the repo. They are signed separately and synced through the labeling service." A labeler serves them through com.atproto.label.subscribeLabels, which Bluesky's post calls "a realtime subscription of all labels."

Labelers also take reports. When you report a post in the Bluesky app, you choose which of your labelers receives it, and Bluesky's post notes that "a Labeler is not required to accept reports."

What is Ozone?

Ozone is the open-source labeling tool that Bluesky's own moderation team uses. The AT Protocol moderation guide describes it as "a labeling service and web frontend for making moderation decisions." Bluesky released it so that anyone running a labeler can set up the service account, review reports and publish labels from one web interface.

Ozone fits a team of human moderators working through a report queue. Bluesky also lists Osprey, "an event stream decisions engine and analysis UI designed to investigate and take automatic action," for rule-based labeling at scale. Anyone can run a labeler with either tool or with custom software that serves the label endpoints.

What does the default Bluesky moderation labeler do?

The Bluesky Moderation Service is the labeler built into the Bluesky app, and every user gets its labels without subscribing. Its handle is moderation.bsky.app. Bluesky explains the setup in its architecture post: "In the Bluesky app, we hardcode our in-house moderation to provide a strong foundation that upholds our community guidelines."

Labelers you add stack on top of that base. You cannot unsubscribe from the Bluesky Moderation Service inside the Bluesky app. The same post says that users who disagree with Bluesky's application-level moderation "can choose to use another client on the network with its own moderation system."

What are label values on Bluesky?

A label value is the short string a labeler attaches, such as spam or graphic-media, and its definition decides what the app does with it. Values use lowercase letters and dashes only. The AT Protocol defines a few global values that behave the same everywhere:

Label value	What the Bluesky app does
!hide	Puts a warning on content that cannot be clicked through and filters it from listings
!warn	Puts a warning on content that can be clicked through
!no-unauthenticated	Makes content unavailable to logged-out users
porn	Warns on images, viewable only by users 18+ with adult content on
sexual	Same as porn, for less intense content
graphic-media	Same as porn, for violence and gore
nudity	Warns on images, not age-gated, defaults to ignore
bot	Marks the account as automated

Labelers can also define custom values. Each custom value sets blurs (content, media or none), severity (alert, inform or none) and a defaultSetting of hide, warn or ignore. Bluesky's guide gives examples: a misinformation label blurs nothing and shows an alert, and a verified-user label shows a neutral badge. Users can apply six of the global values to their own posts as self-labels.

How do you subscribe to a labeler on Bluesky?

You subscribe to a labeler from its profile in the Bluesky app, then set how each of its labels behaves.

1. Open the labeler's profile. Labelers have ordinary Bluesky accounts, so you can find them through search or a link.
2. Tap Subscribe to Labeler.
3. Go through the labeler's list of labels and set each one. Labels that blur content or carry an alert offer Hide, Warn or Off. Informational labels offer Hide, Show badge or Off.
4. Open Settings, then Moderation, and check the Advanced section, which lists your labelers.
5. To stop, open the labeler's profile and tap Unsubscribe.

Hide does more than Warn. Bluesky's developer guide says the two are "basically similar, except that hide will also filter the labeled content from feeds and listings." Your choices are stored in your account preferences, and the subscription itself is not public. Bluesky's architecture post says: "A user subscribing to a labeler is not public, though the PDS and AppView can privately infer which users are subscribed to which services."

How many labelers can you subscribe to on Bluesky?

The Bluesky app caps you at twenty labelers. When you hit the cap, the app shows: "We're sorry! You can only subscribe to twenty labelers, and you've reached your limit of twenty." The app's source code sets the same number as MAX_LABELERS = 20.

Bluesky's developer guide on labels explains the cap at the protocol level: "You may include up to 20 labelers. The Bluesky application hardcodes Bluesky's moderation for inclusion, leaving 19 additional subscriptions to the users." The newer AT Protocol subscription guide states no number. Plan on 19 labelers of your own next to the Bluesky Moderation Service, and drop unused ones before you add more.

Can a labeler remove posts from Bluesky?

No. A labeler annotates content and each app decides what to do with the labels. Bluesky's developer guide lists labels as one of three separate layers: network takedowns that filter content from the APIs, labels from moderation services, and user controls such as mutes and blocks.

Two consequences follow:

• Blocking a labeler does not stop it labeling you. The Bluesky app warns: "Blocking does not prevent this labeler from placing labels on your account."
• A label on a profile is narrower than one on an account. A label on the account puts warnings on every post the account makes. A label on the profile record only affects the avatar, banner and profile view, and the guide says "the 'hide' preference has no effect when the label is on a profile."

How a label reaches your feed

Labeler signs the label

Labeling service serves it

Your Bluesky app reads it

Your setting: Hide, Warn or Off

Post stays on the network

Do Bluesky labels change what keyword monitoring finds?

Bluesky labels change what the Bluesky app shows you, not what gets posted to the network. The firehose that tools read is a stream of repository events, which Bluesky's docs list as "posts, likes, follows, handle changes, etc", and labels from labelers are not part of the repository. A firehose reader receives the post record. The label lives on the labeler's separate stream.

Inside your own Bluesky app, a label set to Hide removes matching posts from your feeds and listings, including posts that mention your product. If you browse Bluesky to find conversations, set labels you care about to Warn instead of Hide, so you still see the post and decide yourself. Bluesky search operators help narrow what you browse, and negative keywords cut noise without hiding posts on the network. Every Bluesky account, labelers included, keeps a stable identity through its AT Protocol DID, which is what a label on an account points at.

How does RedReplier fit next to Bluesky labelers?

RedReplier reads the same firehose described above, where post records carry no labels from labelers. Bluesky monitoring in RedReplier reads the live firehose for the terms, brand names and phrases you add, and ranks each match by relevance. Include and exclude rules filter out lookalikes. Matches land on your RedReplier dashboard within minutes of a post going live, and email alerts go out as digests on a cadence you set per keyword, from hourly to daily. RedReplier drafts a reply and never posts it for you, so you open the post in Bluesky, see any label on it, and post the reply yourself. For how this differs from tracking a market as a whole, see social monitoring vs social listening.

Frequently asked questions

What is a Bluesky labeler?

A Bluesky labeler is a moderation service that publishes labels on posts, accounts, lists and feeds. Any account can become one by publishing an app.bsky.labeler.service record. Users subscribe to the labelers whose labels they want the app to apply.

Who runs the default labeler on Bluesky?

Bluesky runs it as the Bluesky Moderation Service, handle moderation.bsky.app. The Bluesky app hardcodes it, so every user gets its labels. Other labelers stack on top.

How many labelers can you subscribe to on Bluesky?

The Bluesky app stops at twenty and shows a "You can only subscribe to twenty labelers" message. Bluesky's developer guide counts Bluesky's own service in that total, which leaves 19 slots for labelers you choose.

What is the difference between Hide and Warn for a label?

Warn puts the content behind a cover or adds a warning, and you can still open it. Hide does the same and also removes the labeled content from feeds and listings. Off ignores the label.

Can anyone see which labelers you subscribe to?

No. Bluesky says a labeler subscription is not public, though the servers that answer your requests can infer it. Your label settings are stored as preferences on your account.

Does a label delete a post on Bluesky?

No. A label annotates the post and the app decides whether to hide, warn or badge it. Deleting content from the network is a separate takedown layer that Bluesky's guide lists apart from labels.

How do you unsubscribe from a labeler on Bluesky?

Open the labeler's profile in the Bluesky app and tap Unsubscribe. Its labels then stop applying to your view. You cannot unsubscribe from the Bluesky Moderation Service, because the app hardcodes it.

Can you report a post to a labeler on Bluesky?

When you report a post in the Bluesky app, you choose which of your labelers receives the report. Bluesky notes that a labeler is not required to accept reports, so a labeler can ignore yours.

Does blocking a labeler stop its labels on Bluesky?

Blocking a labeler does not stop it from placing labels on your account. The Bluesky app warns about this directly. To stop its labels from shaping your view, unsubscribe from it.

Do Bluesky labels hide posts from keyword monitoring?

Labels from labelers are not part of the repository, so a firehose reader still receives the post record. Labels only change what your own Bluesky app shows. A label set to Hide removes matching posts from your feeds and listings, but not from the network.