Dev Server#

Bun development server with HMR (Hot Module Replacement) enabled. Thin wrapper around Bun.serve() with development: true — automatic re-bundling, source maps, and hot reload when files change.

Import#

typescript

import { devServer } from "@buntok/core/dev";

Usage#

Minimal — default returns 404#

typescript

import { devServer } from "@buntok/core/dev";

devServer({
  port: 3000,
  onReady: (info) => console.log(`Dev server: http://localhost:${info.port}`),
});

With routes — serve HTML files#

typescript

import { devServer } from "@buntok/core/dev";
import homepage from "./index.html";

devServer({
  port: 3000,
  routes: { "/": homepage },
  onReady: (info) => console.log(`Dev server: http://localhost:${info.port}`),
});

With custom fetch handler#

typescript

import { devServer } from "@buntok/core/dev";

devServer({
  port: 3000,
  fetch: (req) => new Response(`Hello from ${req.url}`),
});

Options#

Option	Type	Default	Description
port	number	3000	Port to listen on. `0` = random available port
hostname	string	"localhost"	Hostname to bind to
routes	Record<string, unknown>	—	Bun routes object — maps paths to HTML files or handlers
fetch	(req: Request) => Response	404 handler	Custom fetch handler — used when no routes provided
hmr	boolean	true	Enable Hot Module Replacement
console	boolean	true	Echo browser console to terminal
onReady	(info) => void	—	Called when server starts
...rest	BunServeOptions	—	Any additional Bun.serve() options

When to Use#

Web/frontend development — HMR for HTML, CSS, JS changes
Full-stack apps — serve templates + API routes simultaneously
Framework development — test BunTok itself with hot reload

When NOT to Use#

Pure API servers — bun --watch server.ts is simpler and sufficient
Vercel deployment — Vercel handles serving; use app.fetch() instead
Production — always use bun run build + bun run start

Return Value#

Returns the Bun.serve() instance:

typescript

const server = devServer({ port: 0 });
console.log(server.port); // actual port (useful with port: 0)
server.stop(); // stop the server

Info

devServer() without routes or fetch returns 404 for all requests by default. This is useful for testing that the server starts correctly.

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