camber 0.1.6 - Docs.rs

Camber is opinionated async Rust for IO-bound services on top of Tokio.

In development, publicly usable, and actively dogfooded.

Camber is a library and project tool for the large middle of Rust services that are IO-bound, not scheduler experiments.

Install

cargo add camber

cargo install camber-cli

Quick Start

Build HTTP services without extractors, Tower, or #[tokio::main]. Async handlers on a Tokio core.

cargo install camber-cli
camber new my-service --template http
cd my-service
cargo run

use camber::RuntimeError;
use camber::http::{self, Response, Router};

fn main() -> Result<(), RuntimeError> {
    let mut router = Router::new();
    router.get("/hello", |_req| async { Response::text(200, "Hello, world!") });
    http::serve("0.0.0.0:8080", router)
}

Use http::serve(...) by itself for the default case. Wrap it in runtime::builder().run(...) only when you need runtime configuration such as worker counts, shutdown timeouts, or registered resources.

Docs

If you're evaluating Camber as a library, start with Tokio/Axum to Camber or the Reference.

The README is the overview. docs/reference/ and docs.rs are the exhaustive public surface.

Reverse Proxy (Homelab / WIP)

Config-driven reverse proxy with auto-TLS and health checks. Suited for homelab and internal deployments. Not yet a production edge replacement.

cargo install camber-cli
camber serve config.toml

listen = "0.0.0.0:443"

[tls]
auto = true
email = "admin@example.com"

[[site]]
host = "jellyfin.example.com"
proxy = "http://192.168.1.10:8096"

[[site]]
host = "immich.example.com"
proxy = "http://192.168.1.10:2283"

[[site]]
host = "grafana.example.com"
proxy = "http://192.168.1.10:3000"
health_check = "/api/health"

Full setup guide: Proxy Quickstart

Middleware

use camber::http::{cors, compression, rate_limit};

router.use_middleware(cors::allow_origins(&["https://app.example.com"]));
router.use_middleware(compression::auto());
router.use_middleware(rate_limit::per_second(100)?);

Auth is just middleware:

use camber::http::{Response, IntoResponse};

router.use_middleware(|req, next| {
    let authorized = req.header("authorization").is_some_and(valid);
    async move {
        match authorized {
            true => next.call(req).await,
            false => Response::text(401, "unauthorized")?.into_response(),
        }
    }
});

If middleware needs request data after .await, copy out owned data before entering async move.

For normal HTTP handlers, middleware wraps the full owned Request and Response. For gRPC and proxy_stream, middleware acts as a request gate before streaming begins.

WebSocket & SSE

router.ws("/chat", |req, mut conn: WsConn| {
    while let Some(msg) = conn.recv() {
        conn.send(&format!("echo: {msg}"))?;
    }
    Ok(())
});

router.get_sse("/events", |_req, sse| {
    sse.event("update", r#"{"status":"ok"}"#)?;
    Ok(())
});

For generic chunked responses, use StreamResponse::new() for the default buffer or StreamResponse::with_buffer(status, cap) when you need explicit backpressure tuning.

HTTP Client

use camber::http;

let resp = http::get("https://api.example.com/data").await?;
let resp = http::post_json("https://api.example.com/items", &body).await?;
let resp = http::put("https://api.example.com/items/1", &body).await?;
let resp = http::delete("https://api.example.com/items/1").await?;
let resp = http::patch_json("https://api.example.com/items/1", &body).await?;

let resp = http::client().retries(3).get("https://flaky-api.example.com/data").await?;

Cookies

let session = req.cookie("session_id");
let resp = Response::text(200, "ok")?.set_cookie("session_id", "abc123");

File Uploads

router.post("/upload", |req| async {
    let multipart = req.multipart()?;
    for part in multipart.parts() {
        save(part.filename(), part.data());
    }
    Response::text(200, "uploaded")?
});

Database

use sqlx::PgPool;

let pool = PgPool::connect("postgres://localhost/mydb").await?;

// In a handler:
let user = sqlx::query_as::<_, User>("SELECT * FROM users WHERE id = $1")
    .bind(id)
    .fetch_one(&pool)
    .await?;

Camber does not wrap database drivers. Use sqlx or your preferred ORM directly inside handlers and background tasks.

Observability

use camber::http::otel;
use camber::circuit_breaker;

router.use_middleware(otel::tracing());

let protected = circuit_breaker::wrap(pool)
    .failure_threshold(3)
    .cooldown(Duration::from_secs(30))
    .build();

License

Dual-licensed under MIT and Apache 2.0.