Lesson 1.2: Multi-protocol in one workbench

Difficulty: Beginner | Duration: 10 min | Prerequisites: Lesson 1.1

Overview

The Harbor Combined sample speaks REST, gRPC, SignalR, WebSocket and SSE against the same domain — so one workbench shows every wire side by side. You'll invoke a gRPC unary call, fire a server-streaming method and watch frames arrive live, then switch between protocols without re-pointing anything.

Keep the Combined sample from Lesson 1.1 running (:5101/bowire).

Steps

1. See every protocol in one sidebar

The sidebar groups the Harbor domain by protocol — REST operations, the gRPC greeter-style services, the SignalR hub, the WebSocket + SSE endpoints — all discovered from the one Combined host:

🔌 REST        (HarborStore over HTTP)
🟢 gRPC        (unary + streaming methods)
📡 SignalR     (hub methods + streams)
🔌 WebSocket   (text / binary frames)
📶 SSE         (event stream)

They share the same UI primitives — sidebar, invoke pane, response viewer, recorder — so a polyglot mesh is one workbench, not five tabs.

2. Invoke a gRPC unary method

Pick a unary gRPC method, fill the schema-built form, click Invoke. You get a single response in the same pane shape you saw for REST in Lesson 1.1 — the wire changed, the invoke loop didn't.

3. Fire a server-streaming method

Pick a server-streaming method (gRPC stream or the SSE endpoint). Invoke it: the response pane switches to stream mode and frames arrive live, one after another:

[#1] { … }
[#2] { … }
[#3] { … }

When the stream ends you see the frame count + total duration. A Cancel affordance stops an open stream early.

4. Switch between protocols

Click back into a REST method — no restart, no re-point. Every discovered service stays live in the same workbench simultaneously.

Getting multiple hosts into one workbench

The Combined sample is a single host exposing many wires. When your services are separate processes, you bring them together outside the UI:

Either way, once discovered, the invoke/stream/switch flow above is unchanged.

Key Takeaways

  1. One UI for every wire. REST, gRPC, streaming, messaging — same sidebar, same invoke pane; only the response-pane shape adapts (single vs stream).
  2. Streaming is first-class. Server-streaming methods render a live frames pane with a cancel affordance.
  3. Composing services is a shape concern, not a UI concern. Multiple hosts come together via the CLI (--url) or embedded co-hosting — the workbench treats them identically afterwards.

What's Next

You can drive any service across any protocol. Next: capture what you invoke and replay it.

Continue: → Unit 2: The Workbench — record, mock, assert, cover

Reference