// API schema and metadata
// You'll typically define this in a separate package shared by your server and clients
export const stream = makeWsApi({
  routeType: 'stream',
  url: '/stream',
  requests: {
    ping: schema.object({ echo: schema.string().allowEmptyString().optional() }).optional(),
    hello: schema.any().optional()
  },
  responses: {
    pong: schema.object({
      body: schema.string()
    }),
    hello: schema.object({
      body: schema.string()
    })
  }
});

import expressWS, { WithWebsocketMethod } from 'express-ws';

…

// Add WebSocket support to Express
expressWs(app);
const appWithWs = app as typeof app & WithWebsocketMethod;

registerWsApiHandler(
  appWithWs,
  api.stream,
  {},
  {
    ping: async ({ input, output }) => output.pong({ body: `PONG${(input?.echo?.length ?? 0) > 0 ? ' ' : ''}${input?.echo ?? ''}` }),
    hello: async ({ output }) => output.hello({ body: 'world' })
  }
)