Streams

APIExpose exposes one firehose and 17 filtered streams:

Endpoint	Content
ws://127.0.0.1:12345/ws	every event except esevent.*
ws://127.0.0.1:12345/ws/<stream>	only the events routed to that stream

By default the SDK opens the single /ws firehose. To subscribe to specific streams instead:

const client = new APIExposeClient({ streams: ['score', 'timer', 'frontend'] });

Each stream gets its own socket; the SDK reconnects each one independently and reports a single connection.lost / connection.restored state.

Routing table

Events are routed to streams by their Type prefix:

Stream	Type prefixes
frontend	ui.
marquee	marquee.
topper	topper.
instruction-card	instruction-card.
screen	screen.
panel	panel., theme.
ingame	ingame., retroarch., wrapper.
arcade	arcade., mame., fbneo., outputs.
score	score.live.
timer	timer.live.
retroachievements	retroachievements.
hiscore	hiscore.
media	media.
roms	roms., rom-pack., romset.
system	startup., health., version., hub., config., maintenance., rules., notifications.
control	commands., intent., es-control.
esevent	esevent. — only available here, not on the firehose

Firehose or streams?

For overlays the firehose is simplest and cheap (loopback traffic). Use filtered streams when you embed the SDK in constrained clients or want hard isolation per concern — e.g. a marquee display only opening /ws/marquee.