# Asynchronous plane and brokers

> Puts a message broker behind the same controls as HTTP, in both directions, under an AsyncAPI contract. An HTTP service or an agent tool publishes without…

Concept - Since version 1.5.0 - Flexway v1.6.3 - https://flexway.io/en/docs/product-async/

> Product guide: what the capability brings, for whom, its limits and the version that delivered it - no configuration syntax.

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| **What it does** | Puts a message broker behind the same controls as HTTP, **in both directions**, under an AsyncAPI contract. An HTTP service or an agent tool **publishes** without embedding a broker client (`202` once the message is acknowledged); a browser or an application **subscribes** over SSE or WebSocket (at least once); a partner **receives** signed webhooks (Standard Webhooks), with retries and a dead-letter channel |
| **Why it matters** | Each subscriber reads **its** tenant only, or even its own messages only. Messages carry a standard envelope (CloudEvents) and the trace. No more exposing a broker to the Internet or handing out its credentials |
| **Brokers** | Kafka, RabbitMQ (AMQP 0-9-1), MQTT 5 and 3.1.1 (`1.5.0`); NATS Core and JetStream, AMQP 1.0 - RabbitMQ 4, Azure Service Bus, ActiveMQ Artemis, Solace (`1.6.0`) |
| **Binary payloads** | Avro, Protobuf and CBOR under schema, validated when the operation asks, turned into JSON toward SSE and webhooks; a read-only schema registry (Confluent API) (`1.6.0`) |
| **Use cases** | Notify a customer's screen of its order's events live; deliver invoices to a partner by signed webhook; publish from a service with no Kafka dependency; broadcast a public feed to anonymous visitors |
| **Limits** | The gateway creates no topic or queue; it is a broker client, not a broker; MQTT devices connecting to the gateway (IoT, Sparkplug B, OPC UA) come in `1.7.0` |
| **Since** | `1.5.0`; `1.6.0` for NATS, AMQP 1.0 and binary payloads |
| **Configure** | [Publishing and consuming on a broker](https://flexway.io/en/docs/operations-async/) |