churust-json 0.1.0

Install

[dependencies]
churust = "0.1"
tokio = { version = "1", features = ["full"] }

Plugins and transports are opt-in features on the umbrella crate:

churust = { version = "0.1", features = ["full", "ws", "fs", "tls"] }

Every Churust crate is released in lockstep on one version number, so churust-core, churust-json, and the rest always match the umbrella version.

Churust gives you Ktor's developer experience in Rust: an application engine, a routing DSL, an install(plugin) system, and a phased interceptor pipeline — built on a battle-tested async stack (tokio + hyper + rustls). Churust owns the ergonomic layer; it does not reinvent HTTP parsing or TLS.

use churust::prelude::*;

#[churust::main]
async fn main() -> std::io::Result<()> {
    Churust::server()
        .port(8080)
        .routing(|r| {
            r.get("/", |_call: Call| async { "Hello from Churust 🌀" });
            r.get("/users/{id}", |Path(id): Path<u64>| async move {
                format!("user #{id}")
            });
        })
        .start()
        .await
}

Features

• Hybrid handlers — write call-style (|call: Call|) or with typed extractors (Path<T>, Query<T>, State<T>, Json<T>, BearerToken, Principal<P>) — mix freely in one handler.
• install(plugin) — Ktor-style plugins composed over a named pipeline (Setup → Monitoring → Plugins → Call → Fallback) for deterministic order.
• Built-in plugins — JSON content negotiation, request logging, CORS, and authentication (Bearer / Basic / JWT).
• Typed app state / DI — .state(T) then extract State<T>.
• Layered config — defaults < churust.toml < env (CHURUST_*) < code DSL.
• Secure by default — body-size limits, request timeouts, panic isolation (a panicking handler returns 500, never crashes the server), no version banner, opt-in rustls TLS.
• Fast, in-process tests — TestClient drives the full pipeline without binding a socket.

Workspace layout

Enable plugins via features (full enables all four; tls enables rustls):

[dependencies]
churust = { version = "0.1", features = ["full"] } # json, logging, cors, auth
tokio = { version = "1", features = ["full"] }

A fuller example

use churust::prelude::*;
use serde::{Deserialize, Serialize};
use std::sync::Mutex;

#[derive(Clone, Serialize, Deserialize)]
struct Note { id: u64, text: String }
#[derive(Deserialize)]
struct NewNote { text: String }
#[derive(Clone)]
struct Admin { name: String }
struct Store { notes: Mutex<Vec<Note>> }

#[churust::main]
async fn main() -> std::io::Result<()> {
    Churust::server()
        .state(Store { notes: Mutex::new(Vec::new()) })
        .install(CallLogging::new())
        .install(ContentNegotiation::new())  // renders errors as JSON
        .install(Cors::permissive())
        .install(Auth::bearer(|token: String| async move {
            (token == "admin-token").then(|| Admin { name: "admin".into() })
        }))
        .routing(|r| {
            r.get("/notes", |s: State<Store>| async move {
                Json(s.notes.lock().unwrap().clone())
            });
            // Asking for `Principal<Admin>` enforces auth (401 otherwise).
            r.post("/notes", |Principal(_a): Principal<Admin>,
                              s: State<Store>,
                              Json(input): Json<NewNote>| async move {
                let mut notes = s.notes.lock().unwrap();
                let note = Note { id: notes.len() as u64 + 1, text: input.text };
                notes.push(note.clone());
                (StatusCode::CREATED, Json(note))
            });
        })
        .start()
        .await
}

$ curl localhost:8080/notes
[]
$ curl -X POST localhost:8080/notes -d '{"text":"hi"}'
{"error":"authentication required","status":401}
$ curl -X POST localhost:8080/notes -H 'authorization: Bearer admin-token' \
       -H 'content-type: application/json' -d '{"text":"hi"}'
{"id":1,"text":"hi"}

WebSockets (feature ws)

Opt in with features = ["ws"]. A handler takes the WebSocketUpgrade extractor and calls on_upgrade to switch the request into a bidirectional socket (a plain GET to the route is rejected with 426 Upgrade Required):

use churust::prelude::*;
use churust::ws::{Message, WebSocketUpgrade};

r.get("/echo", |ws: WebSocketUpgrade| async move {
    ws.on_upgrade(|mut sock| async move {
        while let Some(Ok(msg)) = sock.recv().await {
            if matches!(msg, Message::Close) || sock.send(msg).await.is_err() {
                break;
            }
        }
    })
});

churust = { version = "0.1", features = ["ws"] }

See examples/chat for an echo endpoint plus a broadcast room.

Static files & streaming (feature fs)

Response bodies are a Body — either buffered bytes or a lazy stream — so large or dynamic payloads never have to be fully materialized in memory. Body is always available; StaticFiles is behind the opt-in fs feature.

use churust::prelude::*;        // brings StaticFiles into scope under `fs`
use churust::Body;

r.get(
    "/{path...}",
    StaticFiles::dir("./public").index("index.html").handler(),
);
r.get("/numbers", |_c: Call| async {
    let chunks = futures_util::stream::iter(
        (1..=5).map(|i| Ok::<_, std::io::Error>(bytes::Bytes::from(format!("{i}\n")))),
    );
    Response::stream("text/plain", Body::from_stream(chunks))
});

StaticFiles detects the Content-Type from the file extension, serves an optional index file for directories, rejects path traversal (.., absolute paths, symlink escapes) with 404, and streams the file in chunks. See examples/static.

churust = { version = "0.1", features = ["fs"] }

Core concepts

Handlers & extractors

A handler is an async closure/fn returning anything that implements IntoResponse. Arguments are extractors:

• FromCallParts (borrow the request) — any position: Path<T>, Query<T>, State<T>, BearerToken, Principal<P>.
• FromCall (consume the body) — last argument only: Json<T>, Call.

Call itself is the call-style base case (|call: Call| ...).

Pipeline & plugins

A Plugin registers Middleware into a Phase. Middleware own the Call, may mutate it, call next.run(call), and post-process the Response (the onion model). Phase order is fixed and deterministic regardless of install order.

Configuration

# churust.toml
[server]
host = "0.0.0.0"
port = 8080
max_body_bytes = 1048576
request_timeout_ms = 30000

[tls]            # requires the `tls` feature
cert = "cert.pem"
key  = "key.pem"

Churust::from_config() loads churust.toml + CHURUST_* env vars; chained DSL setters override. Example: CHURUST_SERVER_PORT=9090.

Testing

use churust::TestClient;

let app = build_app();
let client = TestClient::new(app);
let res = client.get("/users/1").send().await;
assert_eq!(res.status(), StatusCode::OK);

Development

cargo test --workspace                  # all unit + integration tests
cargo test -p churust --features full   # umbrella with all plugins
cargo test -p churust-core --features tls
cargo clippy --workspace --all-targets -- -D warnings
cargo run -p hello        # http://127.0.0.1:8080
cargo run -p api

Status

Churust v1 is feature-complete: routing, hybrid extractors, the four core plugins, named phases, config, state, timeouts, TLS, and the #[churust::main] macro. v2.0 adds WebSockets behind the opt-in ws feature (see above). v2.1 adds streaming response bodies (the always-on Body type) and static file serving (StaticFiles, behind the opt-in fs feature). Still deferred (YAGNI): sessions, response compression, HTTP/3, route-scoped middleware sugar.

Design docs and build plans live in docs/.

License

MIT