API Overview

This page lists the public API surface of SignalARRR across all packages.

Server API (`Cocoar.SignalARRR.Server`)

Registration

csharp

// IServiceCollection extension
services.AddSignalARRR(options => options
    .AddServerMethodsFrom(assembly));

// Requires the Cocoar.SignalARRR.Server.Backplane.Redis package
services.AddSignalARRRRedisBackplane(options => options
    .WithConnectionString("localhost:6379,abortConnect=false")
    .WithChannelPrefix("my-app")
    .WithNodeId("node-1"));

// Requires the Cocoar.SignalARRR.Server.Backplane.Postgres package
services.AddSignalARRRPostgresBackplane(options => options
    .WithConnectionString("Host=db;Database=app;Username=app;Password=...")
    .WithSchema("signalarrr")
    .WithNodeId("node-1"));

// An observable whose events reach subscribers on every node (cluster subjects)
services.AddSignalARRRClusterSubject<OrderChanged>("orders");

// IEndpointRouteBuilder extension
app.MapSignalARRRHub<THub>(path);
app.MapSignalARRRHub<THub>(path, configureOptions);

HARRR (Hub base class)

Member	Type	Description
`ServiceProvider`	`IServiceProvider`	DI container
`Logger`	`ILogger?`	Logger instance
`ClientContext`	`ClientContext`	Current client context
`OnConnectedAsync()`	`Task`	Client connected (registers in ClientManager)
`OnDisconnectedAsync(Exception?)`	`Task`	Client disconnected (unregisters)

Hub methods (wire protocol — called by clients internally):

Method	Description
`InvokeMessage(ClientRequestMessage)`	Fire-and-forget
`InvokeMessageResult(ClientRequestMessage)`	Returns result
`SendMessage(ClientRequestMessage)`	Fire-and-forget (async void)
`StreamMessage(ClientRequestMessage, CancellationToken)`	Server-to-client stream
`StreamItemToServer(Guid, object)`	Client-to-server stream item
`StreamCompleteToServer(Guid, string?)`	Client-to-server stream completion

ServerMethods / ServerMethods<T>

Property	Type	Description
`ClientContext`	`ClientContext`	Current client context
`Context`	`HubCallerContext`	SignalR caller context
`Clients`	`IHubCallerClients`	Client connections
`Groups`	`IGroupManager`	Group management
`Logger`	`ILogger`	Logger

ClientContext

Property	Type	Description
`Id`	`string`	Connection ID
`HARRRType`	`Type`	Hub type
`RemoteIp`	`IPAddress?`	Client IP
`User`	`ClaimsPrincipal`	Authenticated user
`UserValidUntil`	`DateTime`	Token expiration
`ConnectedAt`	`DateTime`	Connection time
`ReconnectedAt`	`List<DateTime>`	Reconnection history
`Attributes`	`ClientAttributes`	Custom key-value storage
`ConnectedTo`	`Uri`	Hub URL

Method	Description
`GetTypedMethods<T>()`	Get typed proxy to call this client
`TryAuthenticate(MethodInfo)`	Validate token, challenge if expired

ClientManager

Method	Description
`WithHub<THub>()`	Select hub — primary entry point for queries. Returns `IClientQuery`
`GetClientById(string)`	Get client by connection ID
`GetAllClients()`	All connected clients across all hubs — this node only
`GetAllClients(predicate)`	Filter those clients

IClientQuery

Returned by WithHub<THub>(). Describes a target set; with a backplane enabled, the filters and the send/invoke methods resolve across the whole cluster.

Method	Description
`WithGroup(string)`	Narrow to a SignalR group — cluster-wide
`WithUser(string)`	Narrow to a user's connections — cluster-wide
`WithAttribute(string, string?)`	Narrow by connection attribute — cluster-wide
`WithLocalFilter(predicate)`	Narrow by any predicate — confines the query to this node
`SendAsync<T>(action)`	Fire-and-forget to the whole target set
`InvokeAllAsync<T, TResult>(func)`	Invoke each client, collect all results
`InvokeOneAsync<T, TResult>(func)`	Invoke until the first success
`LocalClients()`	The matching `ClientContext`s owned by this node
`AddToGroupAsync(connectionId, groupName)`	Add client to SignalR group (tracked in `ClientContext.Groups`)
`RemoveFromGroupAsync(connectionId, groupName)`	Remove client from group
`GetConnectionsAsync<THub>()`	Connection snapshots for the selected hub
`GetConnectionsByUserAsync<THub>(string)`	Connection snapshots for one user
`GetConnectionsInGroupAsync<THub>(string)`	Connection snapshots for one group
`GetConnectionsByAttributeAsync<THub>(string, string?)`	Connection snapshots matching an attribute
`GetOnlineUsersAsync<THub>()`	User presence snapshots for the hub
`IsUserOnlineAsync<THub>(string)`	Check whether a user is online

SignalARRRRedisBackplaneOptionsBuilder

Method	Description
`WithConnectionString(string)`	Configure the Redis-compatible backend connection
`WithChannelPrefix(string)`	Prefix all backplane keys/channels for app isolation
`WithNodeId(string)`	Set a stable logical node identifier
`WithInvokeTimeout(TimeSpan)`	Timeout for cross-node invoke aggregation
`WithHeartbeatInterval(TimeSpan)`	Heartbeat interval for dead-node detection
`WithNodeTimeout(TimeSpan)`	Time after which a node is considered stale

SignalARRRPostgresBackplaneOptionsBuilder

Method	Description
`WithConnectionString(string)`	Npgsql connection string of the PostgreSQL primary
`WithSchema(string)`	Schema for the backplane's tables; also names the notification channels, so it isolates applications sharing a database. Lowercase identifier, max 50 chars. Default `signalarrr`
`WithAutoCreateSchema(bool)`	Create schema and tables on startup (default `true`); off, the tables must exist — see `SignalARRRPostgresBackplaneSchema.GetCreateScript`
`WithCatchUp(bool)`	Replay messages missed while the subscription was down (default `true`); off, they are lost, as with Redis
`WithMessageRetention(TimeSpan)`	How long messages stay replayable, and the longest outage catch-up covers in full. Default 5 minutes
`WithNodeId(string)`	Set a stable logical node identifier
`WithInvokeTimeout(TimeSpan)`	Timeout for cross-node invoke aggregation
`WithHeartbeatInterval(TimeSpan)`	Heartbeat interval for dead-node detection
`WithNodeTimeout(TimeSpan)`	Time after which a node is considered stale; must exceed the heartbeat interval

IClusterSubject<T>

Registered with AddSignalARRRClusterSubject<T>(name, configure?); resolved by T. See Cluster-aware observables.

Member	Description
`Name`	The cluster-wide name events are matched by
`OnNext(T)`	Raise for local subscribers now and for the other nodes fire-and-forget
`PublishAsync(T, CancellationToken)`	Raise and await the hand-off to the backplane
`Subscribe(IObserver<T>)`	It is an `IObservable<T>`: use it with Rx operators or return it from a hub stream method

ClusterSubjectOptions.SerializerOptions sets the JsonSerializerOptions events cross the wire with (default: web defaults).

SignalARRRPostgresBackplaneSchema

Member	Description
`GetCreateScript(string schema = "signalarrr")`	The idempotent DDL (`IF NOT EXISTS`) for the backplane's schema, tables and indexes, for operators who apply it through migrations

Presence models

Type	Purpose
`SignalARRRConnectionSnapshot`	Connection ID, node ID, user ID, groups, and attributes
`SignalARRRUserPresenceSnapshot`	User ID plus aggregated connection IDs and node IDs

Client API (`Cocoar.SignalARRR.Client`)

HARRRConnection

Static method	Description
`Create(Action<HubConnectionBuilder>, options?)`	Create from builder
`Create(HubConnection, options?)`	Wrap existing connection

Method	Description
`GetTypedMethods<T>()`	Get typed proxy for a contract interface
`InvokeCoreAsync<T>(message, ct)`	Call server, await typed result
`SendCoreAsync(message, ct)`	Fire-and-forget
`StreamAsyncCore<T>(message, ct)`	Server-to-client stream
`RegisterInterface<TInterface, TClass>(...)`	Register a server-to-client contract handler (instance, factory or type)
`StartAsync(ct)`	Connect
`StopAsync(ct)`	Disconnect
`DisposeAsync()`	Dispose
`AsSignalRHubConnection()`	Access raw HubConnection

Property	Type	Description
`ConnectionId`	`string?`	Connection ID
`State`	`HubConnectionState`	Connection state
`ServerTimeout`	`TimeSpan`	Server timeout
`KeepAliveInterval`	`TimeSpan`	Keepalive interval
`HandshakeTimeout`	`TimeSpan`	Handshake timeout

Event	Description
`Closed`	Fires when connection closes
`Reconnecting`	Fires when reconnecting
`Reconnected`	Fires when reconnected

TypeScript API (`@cocoar/signalarrr`)

HARRRConnection

class HARRRConnection {
    static create(builderOrConnection, options?): HARRRConnection

    invoke<T>(methodName: string, ...args: unknown[]): Promise<T>
    send(methodName: string, ...args: unknown[]): Promise<void>
    stream<T>(methodName: string, ...args: unknown[]): IStreamResult<T>

    onServerMethod(methodName: string, handler: (...args) => unknown): this

    start(): Promise<void>
    stop(): Promise<void>
    asSignalRHubConnection(): signalR.HubConnection

    onClose(callback: (error?) => void): void
    onReconnecting(callback: (error?) => void): void
    onReconnected(callback: (connectionId?) => void): void

    connectionId: string | null
    state: HubConnectionState
    baseUrl: string
    serverTimeoutInMilliseconds: number
    keepAliveIntervalInMilliseconds: number
}

Exported types

export { HARRRConnection } from './harrr-connection.js'
export { HARRRConnectionOptions } from './harrr-connection-options.js'
export type { ClientRequestMessage } from './models/client-request-message.js'
export type { ServerRequestMessage } from './models/server-request-message.js'
export type { CancellationTokenReference } from './models/cancellation-token-reference.js'

Common types (`Cocoar.SignalARRR.Common`)

ClientRequestMessage

Property	Type	Description
`Method`	`string`	Method name (`ClassName.MethodName`)
`Arguments`	`object[]`	Method arguments
`Authorization`	`string?`	Bearer token
`GenericArguments`	`string[]`	Generic type arguments

ServerRequestMessage

Property	Type	Description
`Id`	`Guid`	Correlation ID for reply
`Method`	`string`	Method name
`Arguments`	`object[]`	Method arguments
`GenericArguments`	`string[]`	Generic type arguments
`CancellationGuid`	`Guid?`	Cancellation correlation ID
`StreamId`	`Guid?`	Stream correlation ID

Attributes

Attribute	Description
`[SignalARRRContract]`	Marks an interface for proxy generation
`[MessageName(string)]`	Override the default method name

Next steps

Wire Protocol — message flow details
Packages — package selection guide
Getting Started — quick setup

API Overview ​

Server API (Cocoar.SignalARRR.Server) ​

Registration ​

HARRR (Hub base class) ​

ServerMethods / ServerMethods<T> ​

ClientContext ​

ClientManager ​

IClientQuery ​

SignalARRRRedisBackplaneOptionsBuilder ​

SignalARRRPostgresBackplaneOptionsBuilder ​

IClusterSubject<T> ​

SignalARRRPostgresBackplaneSchema ​

Presence models ​

Client API (Cocoar.SignalARRR.Client) ​

HARRRConnection ​

TypeScript API (@cocoar/signalarrr) ​

HARRRConnection ​

Exported types ​

Common types (Cocoar.SignalARRR.Common) ​

ClientRequestMessage ​

ServerRequestMessage ​

Attributes ​

Next steps ​

API Overview

Server API (`Cocoar.SignalARRR.Server`)

Registration

HARRR (Hub base class)

ServerMethods / ServerMethods<T>

ClientContext

ClientManager

IClientQuery

SignalARRRRedisBackplaneOptionsBuilder

SignalARRRPostgresBackplaneOptionsBuilder

IClusterSubject<T>

SignalARRRPostgresBackplaneSchema

Presence models

Client API (`Cocoar.SignalARRR.Client`)

HARRRConnection

TypeScript API (`@cocoar/signalarrr`)

HARRRConnection

Exported types

Common types (`Cocoar.SignalARRR.Common`)

ClientRequestMessage

ServerRequestMessage

Attributes

Next steps