ullun-api

Express.js-inspired web framework for Rust — simple, fast, batteries-included

⚠️ Production Note: Requires proper deployment (TLS, auth, rate limiting). See Production Readiness below.

ullun (уллун; Yakutian/Sakha) = "large/great" — powerful yet simple

Why ullun-api?

The Problem: Actix-web is fast but complex. Rocket is ergonomic but heavy. Axum ties you to Tokio internals.

The Solution: An Express.js-style framework for Rust — single-file APIs, minimal boilerplate, maximum performance.

use ullun::prelude::*;

#[tokio::main]
async fn main() {
    App::new()
        .get("/", |_req| async { Ok(Response::text("Hello, World!")) })
        .get_with_params("/hello/{name}", |params| async move {
            Ok(Response::json(serde_json::json!({
                "message": format!("Hello, {}!", params.get("name")?)
            })))
        })
        .run("127.0.0.1:3000")
        .await
        .unwrap();
}

Features

• 🚀 Fast: Built on hyper + tokio, ~150KB compiled binary
• 🎯 Simple: Express.js-style routing, zero boilerplate
• 🔒 Type-safe: Path parameters validated at compile-time
• 🔗 Middleware: Chain middleware like Express.js
• 📦 Batteries-included: JSON serialization, error handling, CORS built-in
• 🎨 Ergonomic: Result<T, E> maps to HTTP status codes automatically

⚠️ Production Readiness

ullun-api is production-ready for small-to-medium APIs (<100k users), but requires proper deployment practices:

✅ Framework Provides

• Memory safety (zero unsafe code)
• Type-safe routing
• Graceful error handling
• CORS & security headers middleware

⚠️ User Must Implement

• Authentication/Authorization - Use middleware (see examples/todo_api.rs)
• Rate Limiting - Use reverse proxy (nginx/Caddy) or custom middleware
• TLS/HTTPS - Use reverse proxy (never expose raw HTTP in production)
• Input Validation - Validate business logic (framework validates types)
• SQL Injection Prevention - Use parameterized queries (sqlx, diesel)
• XSS Protection - Sanitize HTML output (if serving HTML)

📋 Pre-Production Checklist

1. ✅ Implement authentication middleware
2. ✅ Use reverse proxy (nginx/Caddy) for TLS termination
3. ✅ Add monitoring/observability (Prometheus, Sentry)
4. ✅ Follow SECURITY.md checklist
5. ✅ Load test your specific workload (wrk, hey, ab)
6. ✅ Set up error logging and alerting

See SECURITY.md for comprehensive security guidelines.

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Installation

[dependencies]
ullun = "0.1"
tokio = { version = "1", features = ["full"] }
serde = { version = "1", features = ["derive"] }
serde_json = "1"

Quick Start

Hello World

use ullun::prelude::*;

#[tokio::main]
async fn main() {
    App::new()
        .get("/", |_req| async {
            Ok(Response::text("Hello, World!"))
        })
        .run("127.0.0.1:3000")
        .await
        .unwrap();
}

Path Parameters

App::new()
    .get_with_params("/users/{id}", |params| async move {
        let id: u64 = params.get("id")?.parse()
            .map_err(|_| Error::bad_request("Invalid user ID"))?;
        
        Ok(Response::json(serde_json::json!({
            "user_id": id
        })))
    })
    .run("127.0.0.1:3000")
    .await
    .unwrap();

JSON Request Body

#[derive(Deserialize)]
struct CreateUser {
    name: String,
    email: String,
}

async fn create_user(req: Request) -> Result<Response> {
    let body: CreateUser = req.json()?;
    
    Ok(Response::json(serde_json::json!({
        "message": format!("Created user: {}", body.name)
    })))
}

App::new()
    .post("/users", create_user)
    .run("127.0.0.1:3000")
    .await
    .unwrap();

Middleware

use ullun::middleware::{logger, cors};

App::new()
    .middleware(logger)
    .middleware(cors(vec!["*".to_string()]))
    .get("/", |_req| async { Ok(Response::text("Hello!")) })
    .run("127.0.0.1:3000")
    .await
    .unwrap();

API Reference

App

let app = App::new()
    .get(path, handler)           // GET route
    .post(path, handler)          // POST route
    .put(path, handler)           // PUT route
    .delete(path, handler)        // DELETE route
    .get_with_params(path, handler) // GET with path params extractor
    .middleware(middleware)       // Add middleware
    .run(addr);                   // Start server

Handlers

Handlers can be:

• Async functions taking Request → Result<Response>
• Closures with path params: Params → Result<Response>

// Full request access
async fn handler(req: Request) -> Result<Response> {
    let body = req.json::<MyType>()?;
    Ok(Response::json(body))
}

// Path params only
.get_with_params("/users/{id}", |params| async move {
    let id = params.get("id")?;
    // ...
})

Error Handling

Errors automatically map to HTTP status codes:

return Err(Error::bad_request("Invalid input"));      // 400
return Err(Error::unauthorized("Login required"));    // 401
return Err(Error::forbidden("Access denied"));        // 403
return Err(Error::not_found("User not found"));       // 404
return Err(Error::internal("Database error"));        // 500
return Err(Error::custom(418, "I'm a teapot"));       // Custom

Middleware

Create custom middleware:

async fn my_middleware(req: Request, next: Next) -> Result<Response> {
    // Before handler
    println!("Before: {}", req.uri);
    
    let response = next.run(req).await?;
    
    // After handler
    println!("After: {}", response.status);
    
    Ok(response)
}

App::new()
    .middleware(my_middleware)
    // ...

Examples

See the examples/ directory:

• hello_world.rs - Minimal example
• full_api.rs - Full CRUD API with middleware
• todo_api.rs - Complete TODO API with authentication

Run examples:

cargo run --example hello_world
cargo run --example full_api
cargo run --example todo_api

Test the API:

# GET /
curl http://localhost:3000/

# GET with path params
curl http://localhost:3000/hello/world

# POST with JSON
curl -X POST http://localhost:3000/users \
  -H "Content-Type: application/json" \
  -d '{"name":"Alice","email":"alice@example.com"}'

Comparison

Framework	Bundle Size	Learning Curve	Middleware	Type Safety
Actix-web	500KB	High	Complex	★★★★☆
Rocket	600KB	Medium	Good	★★★★★
Axum	300KB	Medium	Tokio-coupled	★★★★☆
ullun-api	~150KB	Low	Express-style	★★★★★

Testing & Benchmarks

# Run tests
cargo test

# Run benchmarks
cargo bench

# Check coverage
cargo tarpaulin --out Html

See TESTING.md and PERFORMANCE.md for details.

Security

✅ No unsafe code
✅ Memory safe (Rust guarantees)
✅ No unwrap() in production paths
✅ Header validation (prevents malformed headers)
✅ Graceful error handling (no panics)

⚠️ User Responsibilities:

• Authentication/authorization implementation
• Rate limiting (reverse proxy or middleware)
• Input validation (business logic)
• SQL injection prevention (parameterized queries)
• XSS protection (if serving HTML)

See SECURITY.md for comprehensive guidelines and best practices.

Roadmap

v0.2

• OpenAPI/Swagger generation
• WebSocket support
• Static file serving
• Form data parsing
• Cookie handling

v0.3+

• Template engine integration
• Database connection pooling helpers
• Rate limiting middleware
• JWT authentication helpers
• Compression middleware

CI/CD

GitHub Actions workflows:

• ✅ CI: Test on Linux/macOS/Windows + Rust stable/beta
• ✅ Security: cargo-audit checks
• ✅ Format: rustfmt checks
• ✅ Lint: clippy checks
• ✅ Coverage: Code coverage reports
• ✅ Benchmarks: Performance tracking
• ✅ Release: Automated builds & publishing

See .github/workflows/ for details.

Contributing

Contributions welcome! See CONTRIBUTING.md for guidelines.

License

Licensed under either of:

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Documentation

• Architecture Guide - Technical deep-dive
• Deployment Guide - Production deployment
• Testing Guide - Testing strategies
• Performance Guide - Optimization tips
• Security Policy - Security best practices

Acknowledgments

• Built on hyper and tokio
• Routing by matchit
• Inspired by Express.js

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Made with ❤️ by yedoma-labs