type

Serve.Options

type Options<WebSocketData, R extends string = never> = Bun.__internal.XOR<HostnamePortServeOptions<WebSocketData>, UnixServeOptions<WebSocketData>> & Bun.__internal.XOR<FetchOrRoutes<WebSocketData, R>, FetchOrRoutesWithWebSocket<WebSocketData, R>>

The type of options that can be passed to serve, with support for routes and a safer requirement for fetch

export default {
  fetch: req => Response.json(req.url),

  websocket: {
    message(ws) {
      ws.data.name; // string
    },
  },
} satisfies Bun.Serve.Options<{ name: string }>;

Referenced types

type XOR<A, B> = Without<A, B> | Without<B, A>

interface HostnamePortServeOptions<WebSocketData>

development?: Development
Render contextual errors? This enables bun's error page
error?: (this: Server<WebSocketData>, error: ErrorLike) => void | Promise<void> | Response | Promise<Response>
Callback called when an error is thrown during request handling
error: (error) => { return new Response("Internal Server Error", { status: 500 }); }
hostname?: string & {} | '0.0.0.0' | '127.0.0.1' | 'localhost'
What hostname should the server listen on?
"127.0.0.1" // Only listen locally
id?: null | string
Uniquely identify a server instance with an ID
When bun is started with the --hot flag:
This string will be used to hot reload the server without interrupting pending requests or websockets. If not provided, a value will be generated. To disable hot reloading, set this value to null.
When bun is not started with the --hot flag:
This string will currently do nothing. But in the future it could be useful for logs or metrics.
idleTimeout?: number
Sets the the number of seconds to wait before timing out a connection due to inactivity.
ipv6Only?: boolean
Whether the IPV6_V6ONLY flag should be set.
maxRequestBodySize?: number
What is the maximum size of a request body? (in bytes)
port?: string | number
What port should the server listen on?
reusePort?: boolean
Whether the SO_REUSEPORT flag should be set.
This allows multiple processes to bind to the same port, which is useful for load balancing.
tls?: TLSOptions | TLSOptions[]
Set options for using TLS with this server
const server = Bun.serve({ fetch: request => new Response("Welcome to Bun!"), tls: { cert: Bun.file("cert.pem"), key: Bun.file("key.pem"), ca: [Bun.file("ca1.pem"), Bun.file("ca2.pem")], }, });

interface UnixServeOptions<WebSocketData>

development?: Development
Render contextual errors? This enables bun's error page
error?: (this: Server<WebSocketData>, error: ErrorLike) => void | Promise<void> | Response | Promise<Response>
Callback called when an error is thrown during request handling
error: (error) => { return new Response("Internal Server Error", { status: 500 }); }
id?: null | string
Uniquely identify a server instance with an ID
When bun is started with the --hot flag:
This string will be used to hot reload the server without interrupting pending requests or websockets. If not provided, a value will be generated. To disable hot reloading, set this value to null.
When bun is not started with the --hot flag:
This string will currently do nothing. But in the future it could be useful for logs or metrics.
maxRequestBodySize?: number
What is the maximum size of a request body? (in bytes)
tls?: TLSOptions | TLSOptions[]
Set options for using TLS with this server
const server = Bun.serve({ fetch: request => new Response("Welcome to Bun!"), tls: { cert: Bun.file("cert.pem"), key: Bun.file("key.pem"), ca: [Bun.file("ca1.pem"), Bun.file("ca2.pem")], }, });
unix?: string
If set, the HTTP server will listen on a unix socket instead of a port. (Cannot be used with hostname+port)

type FetchOrRoutes<WebSocketData, R extends string> = { routes: Routes<WebSocketData, R>; fetch(this: Server<WebSocketData>, req: Request, server: Server<WebSocketData>): MaybePromise<Response> } | { routes: Routes<WebSocketData, R>; fetch(this: Server<WebSocketData>, req: Request, server: Server<WebSocketData>): MaybePromise<Response> }

type FetchOrRoutesWithWebSocket<WebSocketData, R extends string> = { websocket: WebSocketHandler<WebSocketData> } & { routes: RoutesWithUpgrade<WebSocketData, R>; fetch(this: Server<WebSocketData>, req: Request, server: Server<WebSocketData>): MaybePromise<undefined | void | Response> } | { routes: RoutesWithUpgrade<WebSocketData, R>; fetch(this: Server<WebSocketData>, req: Request, server: Server<WebSocketData>): MaybePromise<undefined | void | Response> }