We're adding two new config options: externallyManagedSessions - bool - default: false. When enabled, this allows clients to skip session initialization and instead call tools directly with a session id they've generated externally. Those sessions will be implicitly created on the server and kept alive until `idleTimeoutMS` expires. It is important that session ids are unique and hard to guess otherwise session hijacking is possible. Note that this is primarily geared towards integrations with AWS Bedrock where the AgentCore framework manages sessions internally and spawns MCP servers on demand for each session. httpResponseType - sse | json - default: sse. Controls the response of the MCP server - in cases where clients are unable to establish an sse connection, they may opt in to use the json response type - in that case responses will be returned in full as json and the server won't be able to initiate communication with the client (e.g. for notifications/logs).