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SignalR transport

The default transport for browser / Blazor / .NET clients. Built on ASP.NET Core SignalR, so reconnection, fallback, and authentication integration are inherited from the host.

Install

dotnet add package OpStream.Server.Transports.SignalR

Server setup

builder.Services
    .AddOpStream()
    .UseSqlServer(connStr)
    .AddSignalRTransport();          // (1)

builder.Services.AddSignalR();       // (2)

var app = builder.Build();
app.MapOpStreamSignalR();            // (3)
  1. Register the OpStream SignalR hub services.
  2. Standard ASP.NET Core SignalR bootstrap.
  3. Map the hub at the default path (/opstream/signalr). Override: app.MapOpStreamSignalR("/realtime/op").

Hub methods (client → server)

Method Args Returns
JoinDocument documentId, documentType, protocolVersion SessionJoinResult
SendOp documentId, payload (byte[]), baseRevision OpApplyResult
UpdateAwareness documentId, data (JsonElement) void

Method names live in OpStreamConstants.HubMethods.

Client events (server → client)

Event Payload
ReceiveOp (documentId, opBytes, newRevision)
ReceiveAwareness List of live AwarenessState (initial snapshot on join)
ReceiveAwarenessUpdate A single AwarenessState delta
PeerDisconnected peerId

Event names live in OpStreamConstants.ClientEvents.

.NET client

dotnet add package OpStream.Client.Transports.SignalR

using OpStream.Client.Transports.SignalR;

var client = new SignalROpStreamClient("https://your-app/opstream/signalr");
await client.ConnectAsync();

var join = await client.JoinAsync("doc-1", "text");
Console.WriteLine($"Joined at rev {join.Revision}");

client.OnReceiveOp += (docId, opBytes, rev) => { /* apply locally */ return Task.CompletedTask; };
client.OnReceiveAwareness += peers => { /* render presence */ return Task.CompletedTask; };

await client.SendOpAsync(docId: "doc-1", opBytes, baseRevision: join.Revision);
await client.SendAwarenessAsync("doc-1", JsonSerializer.SerializeToElement(cursor));

Authentication

The hub honors whatever ASP.NET Core authentication you've configured — add [Authorize] to the OpStream hub via standard SignalR options:

builder.Services.AddSignalR(o => { /* options */ });
builder.Services.AddAuthentication(/* ... */);
builder.Services.AddAuthorization();

The peer id assigned at connect time is Context.UserIdentifier when available, otherwise the ConnectionId. Override the user-id resolver via the standard SignalR IUserIdProvider.

For document-level authorization, plug an IDocumentAuthorizer via UseAuthorization<T>().

CORS and origins

If your client lives on a different origin, configure ASP.NET Core CORS with WithCredentials() — required for the SignalR connection handshake.

Scaling out

To run more than one server node, add the Redis backplane. SignalR's own Redis backplane is not required — OpStream's backplane fans ops out at the engine level, which is more efficient than SignalR group broadcasts.

See also