Bun

Confirm your Bun version

• Why this matters: @nextrush/adapter-bun targets Bun's stable Bun.serve() surface.

bun --version
# needs to read 1.x.x or higher

If Bun isn't installed yet, follow the install instructions before continuing.

Install NextRush and the Bun adapter

• Why this matters: unlike Node, the nextrush meta-package does not bundle the Bun adapter — you add @nextrush/adapter-bun alongside it.

$ pnpm add nextrush @nextrush/adapter-bun

Or scaffold instead:

bunx create-nextrush my-api --runtime bun

Behind the scenes:

• createApp and createRouter still come from nextrush — runtime-independent
• listen, serve, and createHandler come from @nextrush/adapter-bun — the meta-package's listen is wired to @nextrush/adapter-node specifically

Run a hello-world server

Create src/index.ts:

import { createApp, createRouter } from 'nextrush';
import { listen } from '@nextrush/adapter-bun';

const app = createApp();
const router = createRouter();

router.get('/', (ctx) => {
  ctx.json({ runtime: 'bun', status: 'ok' });
});

app.route('/', router);
await listen(app, 8080);

Run it:

bun run src/index.ts

✅Expected result — curl http://localhost:8080/ returns {"runtime": "bun", "status": "ok"}

Behind the scenes:

• listen(app, 8080) from @nextrush/adapter-bun calls Bun.serve() directly
• Each request goes to NextRush's router through the same Context API Node uses
• ctx.runtime reads 'bun' because the adapter, not your handler, decides that value
• Hot reload: bun --hot run src/index.ts restarts on file change — no NextRush setup needed

Why Bun diverges from Node

Your server is now running. Before moving on, it's worth understanding what's genuinely different — and what isn't.

Same: the Context API (ctx.json, ctx.params, ctx.query, ctx.set, …), createApp, createRouter, route registration, and middleware all behave identically to Node. Nothing in your route handlers is Bun-specific.

Different: the import path (Step 2) is the real divergence. One behavioral difference follows from a platform gap — Bun.serve() has no built-in request timeout the way node:http does, so @nextrush/adapter-bun adds its own AbortController-based timeout (defaults to 30 seconds, same as Node). The request body size limit is a deliberate match too: Bun.serve() reads the full body before NextRush sees it, so @nextrush/adapter-bun caps maxRequestBodySize at the same 1 MB default as @nextrush/adapter-node.

@nextrush/adapter-bun is a Stable, independently-versioned package — CI-tested against a real Bun runtime, not Node's Bun-compat layer. See the Bun adapter reference for its full surface.