REST vs GraphQL in Bun

⚔️ REST vs GraphQL in Bun

In the world of APIs, two giants dominate the scene — REST and GraphQL. When you're building with Bun, the fastest JavaScript runtime on the block, choosing the right API architecture is more than just preference — it's about performance, flexibility, and dev experience 💡.

In this blog, we’ll compare REST and GraphQL in the context of Bun. We’ll cover setup, code patterns, performance, and real-world usage to help you decide which one suits your next Bun-powered project best 🚀.

🧱 Basic Concepts: REST vs GraphQL

REST (Representational State Transfer) is a convention-based architecture that uses endpoints like /users and HTTP methods like GET, POST, PUT, DELETE.

GraphQL is a query language for APIs that lets clients specify exactly what data they need — no more, no less 🎯.

🔧 Setting Up REST API in Bun

Creating a REST API in Bun is straightforward using its native Bun.serve function.

const users = [
  { id: 1, name: "Alice" },
  { id: 2, name: "Bob" }
];

Bun.serve({
  port: 3000,
  fetch(req) {
    const url = new URL(req.url);
    if (req.method === "GET" && url.pathname === "/users") {
      return new Response(JSON.stringify(users), {
        headers: { "Content-Type": "application/json" }
      });
    }

    return new Response("Not Found", { status: 404 });
  }
});

✅ Simple, fast, and great for traditional applications.

⚙️ Setting Up GraphQL API in Bun

GraphQL requires a schema and resolvers. Bun handles it smoothly with the graphql package.

import { buildSchema, graphql } from "graphql";

const schema = buildSchema(`
  type Query {
    users: [User]
  }
  type User {
    id: ID
    name: String
  }
`);

const root = {
  users: () => [
    { id: 1, name: "Alice" },
    { id: 2, name: "Bob" }
  ]
};

Bun.serve({
  port: 3000,
  fetch: async (req) => {
    const { query } = await req.json();
    const result = await graphql({ schema, source: query, rootValue: root });
    return new Response(JSON.stringify(result), {
      headers: { "Content-Type": "application/json" }
    });
  }
});

✅ Flexible queries, one endpoint, and less over-fetching.

📊 Performance Comparison

• 🚀 Bun + REST is blazing fast for simple, flat data structures and fewer endpoints.
• ⚡ Bun + GraphQL shines when clients need custom data shapes or nested queries.

Benchmarking shows both options perform well on Bun, but REST edges ahead in raw speed due to simpler parsing.

🎯 Use Cases: When to Use What?

💡 Developer Experience

Bun's fast startup and instant reloads make developing both REST and GraphQL fun. But here's how they differ:

• 🧩 REST is easier for beginners and faster to prototype.
• 🔍 GraphQL offers powerful introspection, auto-generated docs, and one endpoint to manage.

🪵 Logging and Debugging

Logging with Bun is super efficient. Here's a quick logger to track REST or GraphQL requests:

function logger(req) {
  console.log(`[${new Date().toISOString()}] ${req.method} ${req.url}`);
}

🔐 Security Considerations

• 🔒 REST APIs should validate request bodies and implement route-based access control.
• 🔒 GraphQL needs query depth limiting and complexity analysis to prevent abuse.

🚀 Final Verdict: REST vs GraphQL in Bun

There's no universal winner — it’s all about your use case.

• Go with REST if you want simple, traditional APIs with strong HTTP caching and easier tooling.
• Go with GraphQL if you’re building modern SPAs, need nested data, or want full control on the client side.

Either way, Bun handles both like a champ 🏆. You're not locked in — you can even mix both in the same project for hybrid flexibility!