.NET Client

Use the IonClient to make typed RPC calls from .NET applications — unary HTTP calls and WebSocket streaming.

Setup

using ion.runtime.client;

var client = new IonClient("https://api.example.com");

// Create a typed service proxy
var userService = client.ForService<IUserService>(spaceId: 1);

ForService<T> creates a typed proxy that passes base arguments to every call.

Unary Calls

// Simple request-response
User user = await userService.GetUser(userId: 42);
Console.WriteLine(user.name);  // fully typed

// Fire-and-forget (void method)
await userService.SendNotification(userId: 42, text: "Hello");

Under the hood, the proxy:

Serializes [spaceId, userId] to CBOR
POSTs to /ion/UserService/GetUser.unary
Deserializes the CBOR response body into User

Streaming Calls

// Server streaming via WebSocket
await foreach (var user in userService.WatchUpdates())
{
    Console.WriteLine($"Updated: {user.name}");
}

// Bidirectional streaming
var channel = Channel.CreateUnbounded<float>();
await foreach (var result in streamService.Floats(channel.Reader.ReadAllAsync()))
{
    Console.WriteLine(result);
}

Error Handling

RPC errors are thrown as IonProtocolError:

try
{
    var user = await userService.GetUser(999);
}
catch (IonProtocolError ex)
{
    Console.WriteLine($"Error {ex.Code}: {ex.Message}");
}

Authentication

var client = new IonClient("https://api.example.com", options =>
{
    options.Ticket = "eyJhbGciOiJIUzI1NiIs...";
});

The ticket is sent via the subprotocol header for WebSocket connections and via a custom header for HTTP requests.

Deadlines

Methods annotated with @deadline(ms) in the schema have automatic request timeouts:

// In the schema:
@deadline(5000)
service SearchService() {
    Search(query: string): SearchResult;
}

// C# client — auto-cancels after 5 seconds
var result = await searchService.Search("hello");