• Snap

snap_openWebSocket

Open a WebSocket connection to the specified URL with optional protocols.

Note: This method is only available to snaps that have the endowment:network-access permission.

Parameters

object

required

The request parameters for the snap_openWebSocket method.

url

string

required

The wss:// URL of the WebSocket connection to open.

protocols

string[]

The optional protocols to use for the WebSocket connection.

Returns

string

The ID of the opened WebSocket connection, which can be used to reference the connection in subsequent calls to snap_sendWebSocketMessage and snap_closeWebSocket.

Example

Manifest

{
  "initialPermissions": {
    "endowment:network-access": {}
  }
}

Usage

// Open a connection to a WebSocket server, e.g., in the JSON-RPC handler of
// the Snap:
snap.request({
  method: 'snap_openWebSocket',
  params: {
    url: 'wss://example.com/socket',
    protocols: ['protocol1', 'protocol2'], // Optional
  },
})

// Listen for events from the WebSocket connection in the `onWebSocketEvent`
// handler of the Snap:
export const onWebSocketEvent: OnWebSocketEventHandler = async ({ event }) => {
  switch (event.type) {
    case 'open':
      console.log(`WebSocket connection opened with origin ${event.origin}`)
      break
    case 'message':
      console.log(`WebSocket message received from origin ${event.origin}:`, event.data)
      break
    case 'close':
      console.log(`WebSocket connection closed with origin ${event.origin}`)
      break
    case 'error':
      console.error(`WebSocket error from origin ${event.origin}:`, event.error)
      break
  }
}