Crate ruststream 

Rust core of the RustStream messaging framework: broker-agnostic traits, message types, codecs, router runtime, and a conformance harness for broker authors.

Cargo features

The core traits, the runtime::RustStream application object, middleware, and dispatch are always present. The rest is additive and opt-in. Codec features are mutually compatible and enable only the deserializers you need.

• json (default): codec::JsonCodec.
• msgpack: [codec::MsgpackCodec].
• cbor: [codec::CborCodec].
• memory: [memory::MemoryBroker], an in-process broker usable in applications, prototypes and tests.
• macros: the #[subscriber], #[ruststream::app], and #[derive(Message)] macros.
• asyncapi: AsyncAPI document generation and the HTML viewer.
• metrics: Prometheus metrics middleware and exporter.
• logging: colored, RUST_LOG-driven console logging via tracing-subscriber ([logging::init]). The generated cli run command installs it automatically.
• conformance: the [conformance::harness] contract suite, per-capability suites in [conformance::capabilities], and broker-agnostic [conformance::helpers] for application tests. Generic over any broker’s TestClient, so it pulls in no concrete broker (enable memory too to run it against [memory::MemoryBroker]).
• cli: the ruststream binary (run, asyncapi gen, new).

Disable defaults (default-features = false) to drop the bundled JSON codec; the core traits, runtime, and dispatch remain. Add back only what you need.

Re-exports

pub use runtime::RustStream;

Modules

codec

Pluggable serialization codecs.

runtime

Application object, middleware and dispatch.

testing

The TestClient trait: contract for a broker’s in-process test transport.

Structs

Buffered

A SubscriptionSource adapter that buffers the wrapped source’s subscriber into a BatchSubscriber.

BufferedSubscriber

The subscriber Buffered opens: the wrapped source’s subscriber plus client-side batching.

Extensions

A per-delivery type-map: at most one value per type, scoped to a single delivery.

Headers

Case-insensitive map of broker-message headers.

Name

The default SubscriptionSource: subscribe by name string via the Subscribe capability.

OutgoingMessage

A message ready to be published, holding borrowed payload and name.

RawMessage

An owned snapshot of a message as it travels through the framework.

ServerSpec

How to reach a broker, for the servers section of an AsyncAPI document.

Enums

AckError

Errors returned by IncomingMessage::ack and IncomingMessage::nack.

Traits

BatchSubscriber

A subscriber that natively delivers messages in batches.

Broker

A connection to a message broker, owning its lifecycle.

DescribeServer

A broker that describes itself as an AsyncAPI server.

IncomingMessage

A message delivered by a Subscriber.

Message

Metadata about a message type, used to name and describe it in an AsyncAPI document.

Partitioned

Messages or publishers that carry a routing key for broker-side partitioning.

Publisher

A producer that sends messages into the broker.

RequestReply

A publisher that supports synchronous request / reply messaging.

Subscribe

A broker whose subscriptions are fully determined by a name string.

Subscriber

A consumer attached to one or more broker names.

SubscriptionSource

A description of one subscription, resolved against a concrete broker at startup.

TransactionalPublisher

A publisher that supports broker-side transactions.