Bun

@nextrush/adapter-bun connects a NextRush Application to Bun.serve(). Bun runs TypeScript natively, so there's no separate build step for local development or for the container image below.

Installation

$ pnpm add nextrush @nextrush/adapter-bun

Minimal deployment

src/index.ts

import { createApp } from '@nextrush/core';
import { createRouter } from '@nextrush/router';
import { serve } from '@nextrush/adapter-bun';

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

router.get('/health', (ctx) => ctx.json({ status: 'ok' }));
app.route('/', router);

serve(app, { port: Number(process.env.PORT ?? 8080) });

bun run src/index.ts

The `nextrush` meta package defaults to Node.js

nextrush's createApp/listen re-export @nextrush/adapter-node. For Bun, import createApp from @nextrush/core directly and call serve() from @nextrush/adapter-bun — as shown above — instead of nextrush's listen().

`serve()` options that matter in production

ServeOptions (@nextrush/adapter-bun)

Property	Type	Description
`port`	`number`= 8080	Port to listen on.
`host`	`string`= '0.0.0.0'	Host/interface to bind to.
`timeout`	`number`= 30000	Request timeout in ms, enforced via `AbortController` (Bun.serve has no built-in per-request timeout).
`maxRequestBodySize`	`number`= 1048576 (1 MB)	Max request body size in bytes, applied at the Bun.serve level.
`shutdownTimeout`	`number`= 30000	Grace period to drain in-flight requests during `close()` before force-closing.
`development`	`boolean`= false	Enables Bun dev-mode features.
`tls?`	`{ cert, key, ca? }`	Enables HTTPS.

Bun's default body-size limit is 128 MB

Bun.serve() defaults to a 128 MB request body limit. @nextrush/adapter-bun always applies maxRequestBodySize (default 1 MB, matching @nextrush/adapter-node) to override that — raise it explicitly for endpoints that accept large uploads.

src/index.ts

import { createApp } from '@nextrush/core';
import { createRouter } from '@nextrush/router';
import { serve } from '@nextrush/adapter-bun';

const app = createApp();
const router = createRouter();
router.get('/health', (ctx) => ctx.json({ status: 'ok' }));
app.route('/', router);

const server = await serve(app, {
  port: Number(process.env.PORT ?? 8080),
  maxRequestBodySize: 10 * 1024 * 1024, // 10 MB
  onListen: ({ port }) => console.log(`listening on ${port}`),
});

process.on('SIGTERM', async () => {
  await server.close(); // drains in-flight requests, then tears down extensions
  process.exit(0);
});

Graceful shutdown

server.close() calls Bun.serve()'s stop(), waits up to shutdownTimeout for in-flight requests to finish, then force-closes remaining connections and tears down extensions. See Reliability for the full shutdown pattern and which signals to handle.

Hot reload in development

bun --hot run src/index.ts

Bun reloads on file change without restarting the process. This is a development convenience — production deployments should still run under a supervisor (systemd, PM2, or a container orchestrator) rather than --hot.

Deploying

Bun apps deploy the same way as any long-running Node-compatible process — a VM, a container, or a platform with native Bun support (e.g. Railway, Fly.io). To containerize:

Dockerfile

FROM oven/bun:1-alpine AS runtime
WORKDIR /app

COPY package.json bun.lock ./
RUN bun install --production

COPY src/ ./src/

ENV NODE_ENV=production
ENV PORT=8080
EXPOSE 8080

USER bun
CMD ["bun", "run", "src/index.ts"]

This Dockerfile is illustrative, not verified

Unlike the Node.js Dockerfile in Docker — which was actually built and health-checked against a running container as part of this documentation's verification gate — this Bun Dockerfile has not been build-tested here. Verify it against your own bun.lock and Bun version before relying on it.

Requirements

Bun >= 1.0.0
@types/bun as a dev dependency for editor/TypeScript support (already declared in @nextrush/adapter-bun's own devDependencies)

Node.js — the default runtime target
Docker — a verified, build-tested Dockerfile (Node.js)
Reliability — graceful shutdown, health checks, timeouts

ServeOptions (@nextrush/adapter-bun)

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