Blazor Server APP

Question

I’m building a Blazor Server application, which uses WebSockets for real-time communication (via SignalR).

By default, Blazor uses MessagePack as the serialization protocol, which results in a binary transfer format. For debugging and interoperability purposes, I’d prefer to use JSON (text format) instead.

Since Blazor Server abstracts away the SignalR connection details (e.g., via MapBlazorHub()), I can’t see how to configure it to use JsonHubProtocol instead of the default.

Question: Is there a supported way in Blazor Server to switch the default SignalR protocol from MessagePack to JSON, so that messages are transferred in text format instead of binary?

I am using .NET 8.0 and builder.Services.AddServerSideBlazor();.

Any guidance on configuring the protocol or middleware at startup would be appreciated.

Answer 1

The messages packets themselves are in a binary format, not JSON, so you can not switch the hub. If converted to JSON, it would just be a base64 string.also, as it’s a persistent websocket connection, there is no middleware. Just the signalr server and client.

note: The request that created the server hub and created the blazor server instance has completed before channel has opened.