broker / queue / rust

Useful messaging without broker ceremony.

Fibril is a lightweight Rust message broker focused on durable queues, explicit delivery semantics, leasing, retries, and predictable operational behavior. Still early. The missing pieces are named, not hidden.

Start running Read docs GitHub

Durability is core and tested. Production readiness is still earned, not claimed.

queue email.send

worker leased

✓ack

delay 30s

queue lifecycletraffic: active

worker.rsexplicit lifecycle

while let Some(msg) = sub.recv().await? {
    match send_email(msg.content()?).await {
        Ok(_) => msg.complete().await?,
        Err(_) => msg.retry_after(30).await?,
    };
}

// retries are behavior, not ceremony

Durable by default

Append-only logs, snapshot, and replay are part of the model.

Settle explicitly

Complete, retry, or fail a message with APIs that read like intent.

Lease under load

Pull-based delivery and bounded prefetch make pressure visible.

current shape

Working parts, plainly stated.

The broker has a useful baseline today. Some reliability features are still being wired through the full stack.

Read project status →

Feature	Status	Notes
Durable queues	tested	Append-only log, snapshot, and replay.
Explicit acknowledgements	available	ACK, requeue, and terminal failure paths.
Delayed publish	internal	Broker/Stroma path exists; public client methods are TODO.
Delayed retries	wiring	State support exists; public path remains incomplete.
Dead lettering	state-tested	Stroma policy exists; public broker config is not exposed.
Backpressure	available	Pull-based delivery and bounded prefetch.
Replication	planned	Design work is in progress.
Transactions	not planned	Not an initial goal.

early observation

A durable path with room to sharpen.

250k+messages/sec ingress

250k+messages/sec egress

Informal internal measurements with 1KB payloads on a Ryzen 5950X. These are architectural sanity checks, not a polished benchmark suite.