@startuml
skinparam sequenceArrowThickness 2
skinparam roundcorner 10
skinparam sequenceParticipant {
  BackgroundColor #222222
  BorderColor #222222
  FontColor white
}
skinparam sequenceLifeLineBorderColor #AAAAAA
skinparam sequenceGroupFontColor white

participant "MCP Server" as Server
participant "MCP Client" as Client
participant "LLM" as LLM

group Initialization

    Client -> Server: Initialization Request
    activate Client
    activate Server
    
    Server --> Client: Initialization Response
    deactivate Server    

    Client -\ Server: Initializated
    deactivate Client
end 

group Inside an Existing Client Invocation
    Client -> Server: Tool/Prompt/Resource Request
    activate Client
    activate Server

    group Sampling
        Server -> Client: sampling/createMessage
        activate Client

        group Model interaction
            Client -> LLM: Forward sampling request
            activate LLM
            LLM --> Client: Return generation
            deactivate LLM
        end

        Client --> Server: Return generation
        deactivate Client
    end

    Server --> Client: Tool/Prompt/Resource Response
    deactivate Server
    deactivate Client
end

@enduml