Adapters

Adapters

The adapter is the platform entry point. It translates HTTP (Node.js, Bun, Deno, or Worker-style fetch) into NextRush's Context, runs the application, and sends the response back.

Same code runs on any adapter; you choose at startup.

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Adapter overview

Adapter	Platform	Entry	Install
@nextrush/adapter-node	Node.js ≥22	listen(app, port)	nextrush (included)
@nextrush/adapter-bun	Bun	listen(app, port) or serve(app, {…})	pnpm add @nextrush/adapter-bun
@nextrush/adapter-deno	Deno	listen(app, port)	pnpm add @nextrush/adapter-deno
@nextrush/adapter-edge	Cloudflare Workers, Vercel Edge	toFetchHandler(app)	pnpm add @nextrush/adapter-edge

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Node.js

import { createApp, createRouter, listen } from 'nextrush';

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

router.get('/', (ctx) => {
  ctx.json({ message: 'Hello' });
});

app.route('/', router);
listen(app, 3000);

listen starts an HTTP server on port 3000. Graceful shutdown: await app.close().

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Bun

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

const app = createApp();
// …routes…

listen(app, 3000);

Or use serve() for more control:

import { serve } from '@nextrush/adapter-bun';

const handler = serve(app, {
  port: 3000,
  hostname: '0.0.0.0',
  trustProxy: true,
});

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Deno

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

const app = createApp();
// …routes…

listen(app, 3000);

Runs under Deno's HTTP server (requires --allow-net permission).

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Edge (Workers / Vercel)

Returns a fetch handler for serverless deployment:

import { createApp } from 'nextrush';
import { toFetchHandler } from '@nextrush/adapter-edge';

const app = createApp();
// …routes…

const handler = toFetchHandler(app);

export default {
  fetch: handler,
};

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Context normalization

All adapters produce the same Context object:

flowchart LR
  Node["Node.js<br/>IncomingMessage"]
  Bun["Bun<br/>Request"]
  Deno["Deno<br/>Request"]
  Edge["Edge<br/>Request"]

  Node -->|→ ctx| C["Context<br/>method, path<br/>params, query<br/>body, headers<br/>status, json()"]
  Bun -->|→ ctx| C
  Deno -->|→ ctx| C
  Edge -->|→ ctx| C

  C --> App["Application<br/>middleware<br/>routing<br/>handlers"]

Loading

Code in middleware and handlers never checks what platform it's on; it just uses ctx.

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Proxy and X-Forwarded headers

Behind a reverse proxy (load balancer, nginx), set proxy: true on the app:

const app = createApp({ proxy: true });

Then adapters trust X-Forwarded-* headers for client IP and protocol. Without proxy: true, those headers are ignored (safe default).

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Development vs production

Choose the adapter that matches your deployment target:

• Local dev: Node, Bun, Deno (all start fast)
• Production on servers: Bun or Node
• Serverless: Edge adapter

Code is identical across all targets; only the entry file changes.

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Adapter API reference

• Node adapter
• Bun adapter
• Deno adapter
• Edge adapter