Akka.NET

The Akka.NET plugin streams every message landing in a tap-mailboxed actor's inbox into the Bowire workbench. You watch a running actor system the same way you watch a gRPC server-stream or an MQTT topic — except the events are inter-actor Tells instead of network frames.

Package: Kuestenlogik.Bowire.Protocol.Akka (sibling repo, not bundled with the CLI)

Setup

bowire plugin install Kuestenlogik.Bowire.Protocol.Akka

Akka.NET runs in-process inside the host application — there is no remote endpoint to point Bowire at. The plugin therefore works in embedded mode only: the host registers its ActorSystem in DI, the plugin resolves it through Initialize(IServiceProvider), and the workbench observes the actor traffic from within the same process. Standalone-CLI mode is not supported (yet — Akka.Cluster.Tools.ClusterClient transport is on the 0.2.0 roadmap).

How it works

  1. Mailbox tap — a custom Akka.NET MailboxType (BowireTapMailbox) wraps the standard unbounded queue and forwards every Enqueue to a per-actor-system extension. Opt-in either globally (replace the default mailbox) or per-actor (Props.WithMailbox("akka.actor.bowire-tap")).
  2. IExtension integration — BowireAkkaExtension owns the broadcast channel + the active-subscriber list. Steady-state cost when nobody's watching: one volatile read per message, no allocation.
  3. Bowire streaming pane — BowireAkkaProtocol exposes one server-streaming method, Tap/MonitorMessages, that yields TappedMessage envelopes (recipient path, sender path, CLR type, payload, timestamp) as JSON.

Wire it up

1. Register the ActorSystem in DI

using Akka.Actor;
using Microsoft.Extensions.DependencyInjection;

var system = ActorSystem.Create("MyApp", hocon);
builder.Services.AddSingleton(system);
builder.Services.AddBowire(); // picks up Kuestenlogik.Bowire.Protocol.Akka via plugin discovery

2. Opt actors into the tap mailbox

Globally — every actor created after this gets tapped:

akka.actor.default-mailbox.mailbox-type = "Kuestenlogik.Bowire.Protocol.Akka.BowireTapMailbox, Kuestenlogik.Bowire.Protocol.Akka"

Per-actor — surgical, leaves the rest at their default mailbox:

akka.actor.bowire-tap = {
  mailbox-type = "Kuestenlogik.Bowire.Protocol.Akka.BowireTapMailbox, Kuestenlogik.Bowire.Protocol.Akka"
}

var orders = system.ActorOf(
    Props.Create<OrdersActor>().WithMailbox("akka.actor.bowire-tap"),
    "orders");

3. Watch in Bowire

Open the workbench (/bowire in embedded mode), pick the Akka.NET tab in the protocol filter, and start streaming Tap/MonitorMessages. Every Tell that lands in a tapped mailbox lands in the stream pane in real time.

Sample

A runnable end-to-end sample lives under samples/Kuestenlogik.Bowire.Protocol.Akka.Sample — three actors arranged in a small harbour workflow plus a 2-second port-call ticker, so the live message stream is never quiet.

git clone https://github.com/Kuestenlogik/Bowire.Protocol.Akka.git
cd Bowire.Protocol.Akka
dotnet run --project samples/Kuestenlogik.Bowire.Protocol.Akka.Sample

What it doesn't do (yet)

  • No remote / cluster mode — the plugin needs to run in the host process. Cluster-side observation via Akka.Cluster.Tools.ClusterClient is parked on the 0.2.0 roadmap.
  • No mailbox-snapshot inspection — the tap is a live event stream; there is currently no "show the queue depth + the next N messages" view. Also 0.2.0.
  • No Tell-from-Bowire — the workbench observes; it does not yet inject messages back into actors. Coming in 0.3.0 alongside typed-payload roundtripping via the configured Akka serializer.
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