Pub-sub broadcast

One publisher. Thousands of subscribers. Milliseconds.

Push live updates to every connected subscriber at once — through WebSocket, HTTP/3, or MQTT for IoT fleets. The same channel feeds them all.

Channel-scoped fan-out·WebSocket / SSE / WT / MQTT·Cleartext or E2EE

1 → Nsingle publish, parallel fan-out

~40 msmedian end-to-end latency

4 lanesWS · SSE · HTTP/3 · MQTT

Channelsindependent subscribe scopes

Use cases

What customers build with it

Whenever one event needs to reach many listeners at once.

Live sports scores & events

Push score updates and event timeline to every connected fan in the same instant. No polling, no stale UIs.

Media · Sports

Real-time market data

Push tick-level prices to every trading client. Channel per symbol, subscribers attach to the symbols they care about.

Fintech · Trading

IoT fleet telemetry & commands

MQTT subscribers across thousands of devices. One broadcast on a channel, every device gets it — no per-device delivery loop.

IoT · Industrial

Why DropOnAir for broadcast

Built to be a fan-out, not a queue.

Sub-second fan-out

Median ~40 ms end-to-end on the WebSocket lane. The publisher's frame hits every subscriber in parallel — no per-subscriber retry loop.

Four transport lanes

WebSocket, SSE, HTTP/3, MQTT. Pick what your subscribers can reach — browser, mobile, restrictive corporate net, or IoT fleet on bare devices.

Channel-scoped, multi-tenant

Each broadcast topic is per-app, isolated, ACL-enforced. Subscribers see only the channels they're authorised for.

E2EE or cleartext, per channel

Push public live data as cleartext (high throughput) or encrypt sensitive subscriber-bound updates end-to-end. Same API.

Publish + subscribe

Three lines for either side.

Broadcast in the SDK →

// Publisher
await client.publishBroadcast('scores.live', { home: 2, away: 1 });

// Subscriber
await client.subscribeBroadcast('scores.live');
client.onBroadcast(msg => render(msg));

What you ship in a week

A full fan-out pipeline.

Per-channel publish & subscribe
WebSocket, SSE, HTTP/3 subscriber lanes
MQTT subscribers for IoT fleets
Cleartext or E2EE per channel
Subscriber count metrics per channel
Channel history & replay (event-replay docs)
Per-app ACLs and channel isolation
Webhook fan-out for backend listeners

Ready to publish

Push live updates to every listener at once.

Three lines on each side. The fan-out is on us.

Read the quick-start Broadcast in the SDK