WebSocket connection succeeds but Elysia WebSocket handler is not triggered when running inside Nitro

Environment

node

Reproduction

I am using Elysia as a handler inside Nitro. I enabled WebSocket support in Elysia and the WebSocket connection can be established successfully, but the Elysia WebSocket handler is never executed.

Environment

• Nitro version:
• Elysia version:
• Runtime: Bun
• OS:

Reproduction

Elysia app:

import { Elysia } from 'elysia'
import { websocket } from 'elysia/websocket'

export const app = new Elysia()
  .use(websocket())
  .ws('/ws', function* () {
    console.log('handler entered')

    yield 1
    yield 2
    yield 3
  })

Nitro config:

export default defineNitroConfig({
  features: {
    websocket: true
  }
})

Client:

const ws = new WebSocket('ws://localhost:3000/ws')

ws.onopen = () => {
  console.log('connected')
}

ws.onmessage = (event) => {
  console.log(event.data)
}

Expected behavior

After the WebSocket connection is established, the Elysia WebSocket handler should be executed:

connected
handler entered
1
2
3

Actual behavior

The WebSocket handshake succeeds:

WebSocket connection established

but the Elysia handler is never entered:

(no console output)

No error is thrown.

Describe the bug

none

Additional context

No response

Logs

Start by running the provided Elysia app inside Nitro with the shown websocket configuration and client. Trace Nitro's websocket handling and the Elysia integration to find why the successful handshake does not invoke the registered /ws handler. Done means the handler runs after connection and the client receives 1, 2, and 3.