Deno

@nextrush/adapter-deno connects a NextRush Application to Deno.serve(). Deno is secure-by-default — the process has no filesystem, network, or environment access until you grant it explicitly with --allow-* flags.

Installation

Deno resolves npm packages directly with the npm: specifier, or via an import map:

server.ts

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

deno.json

{
  "imports": {
    "@nextrush/core": "npm:@nextrush/core",
    "@nextrush/adapter-deno": "npm:@nextrush/adapter-deno",
    "@nextrush/router": "npm:@nextrush/router"
  }
}

Minimal deployment

server.ts

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

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

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

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

deno run --allow-net --allow-env server.ts

The `nextrush` meta package defaults to Node.js

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

Required permissions

Deno requires explicit flags for every capability the app touches:

Common permission flags

Property	Type	Description
`--allow-net`	`flag`	Required — binds the HTTP server and accepts connections.
`--allow-env`	`flag`	Required if reading `Deno.env.get(...)` for port/config.
`--allow-read`	`flag`	Only if serving static files or reading TLS cert/key from disk.

# Minimal — server only, no env/file access
deno run --allow-net server.ts

# With environment-driven config
deno run --allow-net --allow-env server.ts

# With TLS certs read from disk
deno run --allow-net --allow-env --allow-read server.ts

`serve()` options that matter in production

ServeOptions (@nextrush/adapter-deno)

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 `Promise.race` (Deno.serve has no built-in per-request timeout).
`shutdownTimeout`	`number`= 30000	Grace period to drain in-flight requests during `close()` — guards against `server.shutdown()` hanging on a stalled connection.
`cert?`	`string`	TLS certificate (enables HTTPS with `key`).
`key?`	`string`	TLS private key.

server.ts

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

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

const server = serve(app, {
  port: Number(Deno.env.get('PORT') ?? '8080'),
  onListen: ({ port }) => console.log(`listening on ${port}`),
});

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

await server.finished;

server.finished resolves when the underlying Deno.serve() instance stops — awaiting it keeps the process alive until shutdown completes. See Reliability for the full graceful-shutdown pattern.

HTTPS / TLS

const cert = await Deno.readTextFile('./cert.pem');
const key = await Deno.readTextFile('./key.pem');

serve(app, { port: 443, cert, key });

Deno Deploy

Deno Deploy runs a handler function rather than a long-lived Deno.serve() call you own — use createHandler() and let the platform own the server:

main.ts

import { createApp } from '@nextrush/core';
import { createRouter } from '@nextrush/router';
import { createHandler } from '@nextrush/adapter-deno';

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

Deno.serve(createHandler(app));

Requirements

Deno >= 2.0

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

Common permission flags

ServeOptions (@nextrush/adapter-deno)

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