name: spacedust description: Connect to the Spacedust real-time interactions firehose for AT Protocol. Use when building live notifications, real-time counters, activity feeds, or any feature that needs to react to interactions as they happen. user-invocable: true#

spacedust — real-time interactions firehose#

Streams link events from the entire AT Protocol network over WebSocket with client-side filtering.

Live docs: https://spacedust.microcosm.blue Source: https://github.com/at-microcosm/microcosm-rs/tree/main/spacedust

connecting#

wss://spacedust.microcosm.blue/subscribe?wantedSources=...&wantedSubjectDids=...

Sources use the same collection:path format as Constellation.

filter params#

parameter	what it filters	max values
`wantedSubjects`	specific AT-URIs	50,000
`wantedSubjectDids`	DIDs (all interactions with their content)	10,000
`wantedSubjectPrefixes`	URI/DID prefixes	100
`wantedSources`	interaction types	1,000
`instant`	bypass 21-second delay buffer	boolean

Filter logic: subject params are OR. Sources are AND with subjects. So wantedSubjectDids=X&wantedSources=app.bsky.feed.like:subject.uri = "likes on X's content."

message format#

{"kind":"link","origin":"live","link":{"operation":"create","source":"app.bsky.feed.like:subject.uri","source_record":"at://did:plc:.../app.bsky.feed.like/3lv4ouczo2b2a","source_rev":"3lv4ouczp1x2a","subject":"at://did:plc:.../app.bsky.feed.post/3lgwdn7vd722r"}}

The current (lightweight) version emits only operation: "create" — it keeps no history, so it cannot emit delete events and offers no replay window (origin is always "live"). A future overhaul adds a full forward-link index with hydrated deletes and replay.

dynamic filter updates#

Send JSON on the open connection to replace filters without reconnecting:

{"type": "options_update", "payload": {"wantedSubjectDids": ["did:plc:..."], "wantedSources": ["app.bsky.graph.follow:subject"]}}

quick start#

# watch for new followers of bsky.app
websocat "wss://spacedust.microcosm.blue/subscribe?wantedSources=app.bsky.graph.follow:subject&wantedSubjectDids=did:plc:z72i7hdynmk6r22z27h6tvur"

notes#

events are buffered 21 seconds to filter quickly-undone interactions; instant=true bypasses this
unauthenticated, no API key needed

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