WebSocket

Eden Treaty supports WebSocket using the subscribe method.

import { Elysia, t } from "elysia";
import { websocket } from 'elysia/websocket'
import { treaty } from "@elysia/eden";

const app = new Elysia()
  .use(websocket())
  .ws("/chat", {
    body: t.String(),
    response: t.String(),
    message({ body }) {
            return body
        },
  })
  .listen(3000);

const api = treaty<typeof app>("localhost:3000");

const chat = api.chat.subscribe();

chat.subscribe((message) => {
  console.log("got", message.data);
});

chat.on("open", () => {
  chat.send("hello from client");
});

subscribe() accepts query parameters through its options. Browser WebSockets cannot send arbitrary request headers; use cookies or a server-approved authentication flow.

Response

subscribe() returns an EdenWS wrapper. It provides typed send, subscribe, on, off, and close helpers.

Use chat.ws to access the underlying native WebSocket. The wrapper is not a subclass with every native WebSocket property.