OkHttp — SSE Logging

Experimental

SSE inspection is in early preview and under active development. APIs are marked with @ExperimentalWiretapSseApi and may change in future releases. We're looking for early feedback — please open an issue if you run into problems or have suggestions.

Setup

Use the wiretapped() extension on any EventSourceListener:

@OptIn(ExperimentalWiretapSseApi::class)
val factory = EventSources.createFactory(client)
val source = factory.newEventSource(request, myListener.wiretapped())

Full example

val client = OkHttpClient.Builder()
    .addInterceptor(WiretapOkHttpInterceptor())
    .build()

val listener = object : EventSourceListener() {
    override fun onOpen(eventSource: EventSource, response: Response) {
        println("Connected")
    }

    override fun onEvent(eventSource: EventSource, id: String?, type: String?, data: String) {
        println("Event: $type — $data")
    }

    override fun onClosed(eventSource: EventSource) {
        println("Closed")
    }

    override fun onFailure(eventSource: EventSource, t: Throwable?, response: Response?) {
        println("Failed: ${t?.message}")
    }
}

val request = Request.Builder().url("https://api.example.com/stream").build()
val factory = EventSources.createFactory(client)
@OptIn(ExperimentalWiretapSseApi::class)
factory.newEventSource(request, listener.wiretapped())

How It Works

WiretapOkHttpEventSourceListener wraps all EventSourceListener callbacks:

Callback	What's Logged
onOpen	Connection opened (status: Open) with URL and request headers
onEvent	Event logged with type, data, ID, and byte count
onClosed	Status updated to Closed with timestamp
onFailure	Status updated to Failed with error message

All events are delegated to your original listener after logging.

What Gets Logged

Connection

• URL
• Request headers
• Status transitions (Open → Closed / Failed)
• Failure message (if applicable)
• Timestamps

Events

• Event type (type parameter)
• Data payload
• Event ID (id parameter)
• Byte count
• Timestamp

Configuration

Use the config DSL overload to configure SSE logging:

@OptIn(ExperimentalWiretapSseApi::class)
factory.newEventSource(request, myListener.wiretapped {
    enabled = BuildConfig.DEBUG
})

Or use the simple enabled parameter:

@OptIn(ExperimentalWiretapSseApi::class)
factory.newEventSource(request, myListener.wiretapped(enabled = false))

No-op

The noop module (wiretap-okhttp-noop) provides the same wiretapped() extensions but delegates all callbacks directly without logging.