Struct ClientSession

mcp/client.go:302–321

A ClientSession is a logical connection with an MCP server. Its methods can be used to send requests or notifications to the server. Create a session by calling [Client.Connect]. Call [ClientSession.Close] to close the connection, or await server termination with [ClientSession.Wait].

// Call [ClientSession.Close] to close the connection, or await server
// termination with [ClientSession.Wait].
type ClientSession struct {
	// Ensure that onClose is called at most once.
	// We defensively use an atomic CompareAndSwap rather than a sync.Once, in case the
	// onClose callback triggers a re-entrant call to Close.
	calledOnClose atomic.Bool
	onClose       func()

	conn            *jsonrpc2.Connection
	client          *Client
	keepaliveCancel context.CancelFunc
	mcpConn         Connection

	// No mutex is (currently) required to guard the session state, because it is
	// only set synchronously during Client.Connect.
	state clientSessionState

	// Pending URL elicitations waiting for completion notifications.
	pendingElicitationsMu sync.Mutex
	pendingElicitations   map[string]chan struct{}
}

type clientSessionState struct {
	InitializeResult *InitializeResult