@cosmjs/socket

Cross-platform WebSocket client utilities

Low-level WebSocket client for browser and Node.js environments. Used internally by @cosmjs/tendermint-rpc for WebSocket connections and streaming subscriptions.

npm install @cosmjs/socket

SocketWrapper

Thin abstraction over the native WebSocket API that works in both browsers and Node.js.

Method	Parameters	Returns
constructor	url: string, messageHandler: (event: SocketWrapperMessageEvent) => void, errorHandler: (event: SocketWrapperErrorEvent) => void, openHandler?: () => void, closeHandler?: (event: SocketWrapperCloseEvent) => void, timeout?: number	SocketWrapper
connect	—	void
disconnect	—	void
send	data: string	Promise<void>

Property	Type
connected	Promise<void> (resolves once the socket is open)

StreamingSocket

WebSocket client that exposes received messages as an xstream Stream.

Method	Parameters	Returns
constructor	url: string, timeout?: number	StreamingSocket
connect	—	void
disconnect	—	void
send	data: string	Promise<void>

Property	Type
events	Stream<SocketWrapperMessageEvent>
connected	Promise<void>

ReconnectingSocket

WebSocket client with automatic reconnection logic.

Method	Parameters	Returns
constructor	url: string, timeout?: number, reconnectedHandler?: () => void	ReconnectingSocket
connect	—	void
disconnect	—	void
queueRequest	request: string	void

Property	Type
events	Stream<SocketWrapperMessageEvent>
connectionStatus	ValueAndUpdates<ConnectionStatus>

QueueingStreamingSocket

WebSocket that queues outgoing messages until the connection is established.

Method	Parameters	Returns
constructor	url: string, timeout?: number, reconnectedHandler?: () => void	QueueingStreamingSocket
connect	—	void
disconnect	—	void
queueRequest	request: string	void
getQueueLength	—	number

Property	Type
events	Stream<SocketWrapperMessageEvent>
connectionStatus	ValueAndUpdates<ConnectionStatus>

Event Types

interface SocketWrapperMessageEvent {
  readonly data: string;
  readonly type: string;
}

interface SocketWrapperErrorEvent {
  readonly isTrusted?: boolean;
  readonly type?: string;
  readonly message?: string;
}

interface SocketWrapperCloseEvent {
  readonly wasClean: boolean;
  readonly code: number;
}

ConnectionStatus

enum ConnectionStatus {
  Unconnected,  // 0
  Connecting,   // 1
  Connected,    // 2
  Disconnected, // 3
}