Ohkami

Ohkami - [狼] wolf in Japanese - is intuitive and declarative web framework.

• macro-less and type-safe APIs for intuitive and declarative code
• various runtimes are supported：tokio, async-std, smol, nio, glommio and worker (Cloudflare Workers)
• extremely fast：Web Frameworks Benchmark
• no-network testing, well-structured middlewares, Server-Sent Events, WebSocket, OpenAPI document genration, ...

Quick Start

1. Add to dependencies :

[dependencies]
ohkami = { version = "0.21", features = ["rt_tokio"] }
tokio  = { version = "1",    features = ["full"] }

2. Write your first code with Ohkami : examples/quick_start

use ohkami::prelude::*;
use ohkami::typed::status;

async fn health_check() -> status::NoContent {
    status::NoContent
}

async fn hello(name: &str) -> String {
    format!("Hello, {name}!")
}

#[tokio::main]
async fn main() {
    Ohkami::new((
        "/healthz"
            .GET(health_check),
        "/hello/:name"
            .GET(hello),
    )).howl("localhost:3000").await
}

3. Run and check the behavior :

$ cargo run

$ curl http://localhost:3000/healthz
$ curl http://localhost:3000/hello/your_name
Hello, your_name!

Feature flags

"rt_tokio", "rt_async-std", "rt_smol", "rt_nio", "rt_glommio"：native async runtime

• tokio
• async-std
• smol
• nio
• glommio

"rt_worker"：Cloudflare Workers

npm create cloudflare ./path/to/project -- --template https://github.com/ohkami-rs/ohkami-templates/worker

then your project directory has wrangler.toml, package.json and a Rust library crate. Local dev by npm run dev and deploy by npm run deploy !

See README of template for details.

"sse"：Server-Sent Events

Ohkami responds with HTTP/1.1 Transfer-Encoding: chunked.
Use some reverse proxy to do with HTTP/2,3.

use ohkami::prelude::*;
use ohkami::sse::DataStream;
use tokio::time::{sleep, Duration};

async fn handler() -> DataStream {
    DataStream::new(|mut s| async move {
        s.send("starting streaming...");
        for i in 1..=5 {
            sleep(Duration::from_secs(1)).await;
            s.send(format!("MESSAGE #{i}"));
        }
        s.send("streaming finished!");
    })
}

#[tokio::main]
async fn main() {
    Ohkami::new((
        "/sse".GET(handler),
    )).howl("localhost:3020").await
}

"ws"：WebSocket

Ohkami only handles ws://.
Use some reverse proxy to do with wss://.

WebSocket on Durable Object is available on "rt_worker"!

use ohkami::prelude::*;
use ohkami::ws::{WebSocketContext, WebSocket, Message};

async fn echo_text(ctx: WebSocketContext<'_>) -> WebSocket {
    ctx.upgrade(|mut conn| async move {
        while let Ok(Some(Message::Text(text))) = conn.recv().await {
            conn.send(text).await.expect("failed to send text");
        }
    })
}

#[tokio::main]
async fn main() {
    Ohkami::new((
        "/ws".GET(echo_text),
    )).howl("localhost:3030").await
}

"openapi"：OpenAPI document generation

Ohkami supports as consistent as possible OpenAPI document generation, where most of the consistency between document and behavior is automatically assured by Ohkami's internal work.

Only you have to

• Derive openapi::Schema for all your schema structs
• Make your Ohkami call .generate(openapi::OpenAPI { ... })

to generate consistent OpenAPI document. You don't need to take care of writing accurate methods, paths, parameters, contents, ... for this OpenAPI feature; All they are done by Ohkami.

Of course, you can flexibly customize schemas ( by hand-implemetation of Schema ), descriptions or other parts ( by #[operation] attribute and openapi_* hooks ).

use ohkami::prelude::*;
use ohkami::format::JSON;
use ohkami::typed::status;
use ohkami::openapi;

// Derive `Schema` trait to generate
// the schema of this struct in OpenAPI document.
#[derive(Deserialize, openapi::Schema)]
struct CreateUser<'req> {
    name: &'req str,
}

#[derive(Serialize, openapi::Schema)]
// `#[openapi(component)]` to define it as component
// in OpenAPI document.
#[openapi(component)]
struct User {
    id: usize,
    name: String,
}

async fn create_user(
    JSON(CreateUser { name }): JSON<CreateUser<'_>>
) -> status::Created<JSON<User>> {
    status::Created(JSON(User {
        id: 42,
        name: name.to_string()
    }))
}

// (optionally) Set operationId, summary,
// or override descriptions by `operation` attribute.
#[openapi::operation({
    summary: "...",
    200: "List of all users",
})]
/// This doc comment is used for the
/// `description` field of OpenAPI document
async fn list_users() -> JSON<Vec<User>> {
    JSON(vec![])
}

#[tokio::main]
async fn main() {
    let o = Ohkami::new((
        "/users"
            .GET(list_users)
            .POST(create_user),
    ));

    // This make your Ohkami spit out `openapi.json`
    // ( the file name is configurable by `.generate_to` ).
    o.generate(openapi::OpenAPI {
        title: "Users Server",
        version: "0.1.0",
        servers: vec![
            openapi::Server::at("localhost:5000"),
        ]
    });

    o.howl("localhost:5000").await;
}

• Currently, only JSON is supported as the document format.
• When the binary size matters, you should prepare a feature flag activating ohkami/openapi in your package, and put all your codes around openapi behind that feature via #[cfg(feature = ...)] or #[cfg_attr(feature = ...)].
• In rt_worker, .generate is not available because Ohkami can't have access to your local filesystem by wasm32 binary on Minifalre. So ohkami provides a CLI tool to generate document from #[ohkami::worker] Ohkami with openapi feature.

"nightly"：nightly-only functionalities

• try response

Snippets

Middlewares

Ohkami's request handling system is called "fangs", and middlewares are implemented on this.

builtin fang : CORS, JWT, BasicAuth, Timeout, Context

use ohkami::prelude::*;

#[derive(Clone)]
struct GreetingFang(usize);

/* utility trait; automatically impl `Fang` trait */
impl FangAction for GreetingFang {
    async fn fore<'a>(&'a self, req: &'a mut Request) -> Result<(), Response> {
        let Self(id) = self;
        println!("[{id}] Welcome request!: {req:?}");
        Ok(())
    }
    async fn back<'a>(&'a self, res: &'a mut Response) {
        let Self(id) = self;
        println!("[{id}] Go, response!: {res:?}");
    }
}

#[tokio::main]
async fn main() {
    Ohkami::new((
        // register fangs to a Ohkami
        GreetingFang(1),
        
        "/hello"
            .GET(|| async {"Hello, fangs!"})
            .POST((
                // register *local fangs* to a handler
                GreetingFang(2),
                || async {"I'm `POST /hello`!"}
            ))
    )).howl("localhost:3000").await
}

Typed payload

builtin payload : JSON, Text, HTML, URLEncoded, Multipart

use ohkami::prelude::*;
use ohkami::typed::status;

/* Deserialize for request */
#[derive(Deserialize)]
struct CreateUserRequest<'req> {
    name:     &'req str,
    password: &'req str,
}

/* Serialize for response */
#[derive(Serialize)]
struct User {
    name: String,
}

async fn create_user(
    JSON(req): JSON<CreateUserRequest<'_>>
) -> status::Created<JSON<User>> {
    status::Created(JSON(
        User {
            name: String::from(req.name)
        }
    ))
}

Typed params

use ohkami::prelude::*;

#[tokio::main]
async fn main() {
    Ohkami::new((
        "/hello/:name"
            .GET(hello),
        "/hello/:name/:n"
            .GET(hello_n),
        "/search"
            .GET(search),
    )).howl("localhost:5000").await
}

async fn hello(name: &str) -> String {
    format!("Hello, {name}!")
}

async fn hello_n((name, n): (&str, usize)) -> String {
    vec![format!("Hello, {name}!"); n].join(" ")
}

#[derive(Deserialize)]
struct SearchQuery<'q> {
    #[serde(rename = "q")]
    keyword: &'q str,
    lang:    &'q str,
}

#[derive(Serialize)]
struct SearchResult {
    title: String,
}

async fn search(
    Query(query): Query<SearchQuery<'_>>
) -> JSON<Vec<SearchResult>> {
    JSON(vec![
        SearchResult { title: String::from("ohkami") },
    ])
}

Static directory serving

use ohkami::prelude::*;

#[tokio::main]
async fn main() {
    Ohkami::new((
        "/".Dir("./dist"),
    )).howl("0.0.0.0:3030").await
}

File upload

use ohkami::prelude::*;
use ohkami::typed::status;
use ohkami::format::{Multipart, File};

#[derive(Deserialize)]
struct FormData<'req> {
    #[serde(rename = "account-name")]
    account_name: Option<&'req str>,
    pics: Vec<File<'req>>,
}

async fn post_submit(
    Multipart(data): Multipart<FormData<'_>>
) -> status::NoContent {
    println!("\n\
        ===== submit =====\n\
        [account name] {:?}\n\
        [  pictures  ] {} files (mime: [{}])\n\
        ==================",
        data.account_name,
        data.pics.len(),
        data.pics.iter().map(|f| f.mimetype).collect::<Vec<_>>().join(", "),
    );

    status::NoContent
}

Pack of Ohkamis

use ohkami::prelude::*;
use ohkami::typed::status;

#[derive(Serialize)]
struct User {
    name: String
}

async fn list_users() -> JSON<Vec<User>> {
    JSON(vec![
        User { name: String::from("actix") },
        User { name: String::from("axum") },
        User { name: String::from("ohkami") },
    ])
}

async fn create_user() -> status::Created<JSON<User>> {
    status::Created(JSON(User {
        name: String::from("ohkami web framework")
    }))
}

async fn health_check() -> status::NoContent {
    status::NoContent
}

#[tokio::main]
async fn main() {
    // ...

    let users_ohkami = Ohkami::new((
        "/"
            .GET(list_users)
            .POST(create_user),
    ));

    Ohkami::new((
        "/healthz"
            .GET(health_check),
        "/api/users"
            .By(users_ohkami), // nest by `By`
    )).howl("localhost:5000").await
}

Testing

use ohkami::prelude::*;
use ohkami::testing::*; // <--

fn hello_ohkami() -> Ohkami {
    Ohkami::new((
        "/hello".GET(|| async {"Hello, world!"}),
    ))
}

#[cfg(test)]
#[tokio::test]
async fn test_my_ohkami() {
    let t = hello_ohkami().test();

    let req = TestRequest::GET("/");
    let res = t.oneshot(req).await;
    assert_eq!(res.status(), Status::NotFound);

    let req = TestRequest::GET("/hello");
    let res = t.oneshot(req).await;
    assert_eq!(res.status(), Status::OK);
    assert_eq!(res.text(), Some("Hello, world!"));
}

Supported protocols

• HTTP/1.1
• HTTP/2
• HTTP/3
• HTTPS
• Server-Sent Events
• WebSocket

MSRV ( Minimum Supported Rust Version )

Latest stable

License

ohkami is licensed under MIT LICENSE ( LICENSE or https://opensource.org/licenses/MIT ).