onemessagebus

A typed NDJSON message bus, generic over the vocabulary you declare: one envelope, one filter grammar, payload bounds and redaction, a schema registry with version read-sets, and an emitter and reader over streams.

Nothing here names an agent. Which source words exist, which label keys are reserved and what each admits, and which top-level dimensions an envelope carries are a Vocabulary's to declare — Open reserves nothing, and a program declares its own vocabulary in its own crate, never in the bus. A vocabulary of your own is proven the way Open is: onemessagebus::conformance::drive runs the one table every vocabulary is held to.

use onemessagebus::{Emitter, Filter, Labels, Matcher, Open, Source};
use serde_json::Map;

let emitter = Emitter::<Open>::new("billing-1", Source::from("billing"), Box::new(std::io::stdout()))
    .with_labels(Labels::new().with("tenant", "acme"))
    .with_filter(Filter {
        include: Vec::new(),
        exclude: vec![Matcher::new().kind("heartbeat")],
    });
let written = emitter.emit("invoice-issued", Map::new());
assert_eq!(written.seq, 1);

The wire, the grammar and the registry rules are stated in the repository's docs/wire.md and held by docs/contract.md.