CLI

The ruststream command runs a service and prints its AsyncAPI document through cargo run; cargo generate scaffolds a new one.

ruststream run executes cargo run -- run against the crate's Cargo.toml, and ruststream asyncapi gen executes cargo run -- asyncapi gen. The service's own binary does the work: the main that #[ruststream::app] generates understands both commands. That main hands the commands to run_main, and the runtime::cli module documents them. cargo run -- run and cargo run -- asyncapi gen therefore give the same result without the command installed. The same run is one call from code. -p points at another crate or its Cargo.toml, and --release builds in release mode. asyncapi gen needs the service crate's asyncapi feature; the starter template enables it. The template's console logs come from its logging feature. cargo generate comes from the cargo-generate project; a broker crate ships templates of its own for its transport.

Example

Install the command:

cargo install ruststream --features cli

Scaffold a service from the in-memory starter template:

cargo generate --git https://github.com/powersemmi/ruststream templates/memory --name my-service
cd my-service

The template writes a crate whose main is generated by #[ruststream::app]:

Cargo.toml
src/main.rs
src/orders.rs
src/routes.rs

Run it; Ctrl+C stops it gracefully:

ruststream run

    Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.02s
     Running `target/debug/my-service run`
2026-10-16T07:49:57.254761Z  INFO ruststream::lifecycle starting service service=my-service version=0.1.0 brokers=1 subscribers=2
2026-10-16T07:49:57.254790Z  INFO ruststream::lifecycle broker connected broker="ruststream::memory::MemoryBroker"
2026-10-16T07:49:57.254844Z  INFO ruststream::dispatch subscriber started subscriber=orders input="my_service::orders::Order"
2026-10-16T07:49:57.254854Z  INFO ruststream::dispatch subscriber started subscriber=cancellations input="my_service::orders::Order"
2026-10-16T07:49:57.254859Z  INFO ruststream::lifecycle service running subscribers=2
2026-10-16T07:50:00.281593Z  INFO ruststream::lifecycle shutdown signal received
2026-10-16T07:50:00.281755Z  INFO ruststream::lifecycle service stopped

Print the AsyncAPI document:

ruststream asyncapi gen

    Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.02s
     Running `target/debug/my-service asyncapi gen`
{
  "asyncapi": "3.1.0",
  "info": {
    "title": "my-service",
    "version": "0.1.0"
  },
  "defaultContentType": "application/json",
  "channels": {
    "cancellations": {
      "address": "cancellations",
...

Write it as YAML, to a file, or for a crate in another directory:

ruststream asyncapi gen --yaml
ruststream asyncapi gen -o asyncapi.json
ruststream asyncapi gen -p ../my-service

Example​

Example