rocket

Rocket Core Knowledge

Full Reference: See advanced.md for custom guards (authentication, API key), fairings (CORS, timing), database state, error catchers, and testing patterns.

Deep Knowledge: Use mcp__documentation__fetch_docs with technology: rocket for comprehensive documentation.

Basic Setup

# Cargo.toml
[dependencies]
rocket = { version = "0.5", features = ["json"] }
serde = { version = "1", features = ["derive"] }
serde_json = "1"
tokio = { version = "1", features = ["full"] }

#[macro_use] extern crate rocket;

#[get("/")]
fn index() -> &'static str {
    "Hello, World!"
}

#[launch]
fn rocket() -> _ {
    rocket::build().mount("/", routes![index])
}

Routing

#[get("/users/<id>")]
fn get_user(id: u32) -> String {
    format!("User {}", id)
}

#[post("/users", data = "<user>")]
fn create_user(user: Json<CreateUser>) -> Json<User> {
    Json(User::from(user.into_inner()))
}

#[get("/files/<path..>")]
fn get_file(path: PathBuf) -> Option<NamedFile> {
    NamedFile::open(Path::new("static/").join(path)).ok()
}

// Query parameters
#[derive(FromForm)]
struct Pagination { page: Option<u32>, per_page: Option<u32> }

#[get("/users?<pagination..>")]
fn list_users(pagination: Pagination) -> Json<Vec<User>> {
    let page = pagination.page.unwrap_or(1);
    Json(fetch_users(page, pagination.per_page.unwrap_or(20)))
}

// Mounting
#[launch]
fn rocket() -> _ {
    rocket::build()
        .mount("/", routes![index])
        .mount("/api/v1", routes![list_users, get_user, create_user])
}

Request Guards

// JSON body
#[post("/users", data = "<user>")]
fn create_user(user: Json<CreateUser>) -> Json<User> {
    Json(User::from(user.into_inner()))
}

// Form data
#[post("/login", data = "<login>")]
fn login(login: Form<LoginForm>) -> String {
    format!("Welcome, {}", login.username)
}

// Cookies
#[get("/session")]
fn session(cookies: &CookieJar<'_>) -> Option<String> {
    cookies.get("session_id").map(|c| c.value().to_string())
}