---
description: "Scaffold a service with cargo generate, run it, and generate its AsyncAPI document."
---
import Tabs from '@theme/Tabs';
import TabItem from '@theme/TabItem';
# Quick start
The fastest way to a running service is to scaffold one with `cargo generate`.
## Scaffold a project
```bash
cargo install cargo-generate
cargo generate --git https://github.com/powersemmi/ruststream templates/memory --name my-service
cd my-service
```
Scaffolding needs only `cargo generate`. `templates/memory` is the starter template for the
in-memory broker. A broker crate that ships a template is scaffolded the same way, naming that
crate's repository and the template's path (for example
`--git https://github.com/powersemmi/ruststream-nats templates/nats`); the broker's own
documentation names the templates it has. `cargo generate` writes an idiomatic, multi-file project:
```
my-service/
├── Cargo.toml
└── src/
├── main.rs # #[ruststream::app] builds the service and mounts the router
├── orders.rs # handlers as #[subscriber] functions (one publishes a reply)
└── routes.rs # collects the handlers into a Router
```
## Run it
`#[ruststream::app]` generates `main`, so the binary already understands the framework commands:
```bash
cargo run -- run # or: ruststream run, with the CLI installed
```
`cargo run -- run` starts a tokio runtime. The service runs until you press <kbd>Ctrl</kbd>+<kbd>C</kbd>. It needs
no external broker. The template turns on the `logging` feature, so the service prints its log
to the terminal, and the handlers log through `tracing`.
## Generate the AsyncAPI document
```bash
cargo run -- asyncapi gen
```
The command prints the AsyncAPI document as JSON. The output flags (`-o`, `--yaml`) and the
document itself are covered in the [`asyncapi` module](https://docs.rs/ruststream/latest/ruststream/asyncapi/index.html).
## What the entry point looks like
<Tabs groupId="api">
<TabItem value="macros" label="Macros">
```rust title="src/main.rs" reference="examples/tutorial/main.rs#main"
```
</TabItem>
<TabItem value="manual" label="Manual">
```rust title="src/main.rs" reference="examples/manual/tutorial/main.rs#main"
```
</TabItem>
</Tabs>
You write a function that builds the service; `#[ruststream::app]` turns it into `main`.
## Next
- Understand each piece in the [tutorial](tutorial.md).
- Learn the handler forms in [Subscribers](https://docs.rs/ruststream/latest/ruststream/runtime/index.html#subscribers).
- Drive everything from the [CLI](https://docs.rs/ruststream/latest/ruststream/runtime/cli/index.html).