Bun Compat

Bun.serve

Use Bun.serve for compact HTTP services:

Bun.serve({
  port: 8080,
  fetch(req) {
    return new Response(`hello ${new URL(req.url).pathname}`)
  },
})

Gun targets the server-side subset used by application code: request handling, responses, route-like dispatch, and environment configuration.

Request and response patterns

Prefer standard Web APIs where possible:

async function fetch(req: Request) {
  const body = await req.json()
  return Response.json({ received: body })
}

These patterns are easier to test across Bun, Node-compatible runtimes, and Gun builds.

Environment variables

Read environment values at startup or request boundaries:

const token = process.env.API_TOKEN

Validate required variables before accepting traffic.

When to add an adapter

If your code uses Bun-only APIs deeply, add a small adapter module:

export function serve(options) {
  return Bun.serve(options)
}

That keeps compatibility work local if the implementation needs to differ later.