Sharing an HttpClient

By default the library creates its own Ktor client per platform — OkHttp on Android, Darwin on iOS, CIO on JVM. Pass your own to reuse an existing connection pool, proxy configuration, timeouts or interceptors:

socketOptions {
    httpClient = appHttpClient
}

Requirements

The WebSockets plugin must be installed, or the upgrade cannot happen:

val appHttpClient = HttpClient(OkHttp) {
    install(WebSockets)
    // your timeouts, proxy, interceptors…
}

You own its lifetime. The library never closes a client you passed in — closing it while sockets are live kills them.

client.close()        // Sockit releases the engine
appHttpClient.close() // you close yours, after

When it is worth doing

Reuse the app’s client when you need certificate pinning, a corporate proxy, custom timeouts, or request logging that must cover Socket.IO traffic too. In those cases the configuration already exists and duplicating it is how the two drift apart.

Otherwise the default is fine, and it keeps socket traffic isolated from your REST traffic — a misconfigured interceptor cannot then break your realtime connection.

Interaction with trustAllCerts

trustAllCerts is implemented by the library’s own client factory. If you inject an httpClient, the flag is ignored — your client’s TLS configuration is used as-is.

That is the right behaviour: a client you built and configured should not have its certificate validation silently altered by a socket option. See TLS.