@startuml
!include ../diagram-theme.iuml
title Sketch: no Worker dials a carrier yet
participant "Incoming request" as event
participant "Worker entry\n~#[event(fetch)]" as worker
participant "TwilioClient<CloudflareHttpClient>" as dialer
participant "worker::Fetch\nV8 isolate" as fetch
participant "Twilio API" as carrier

event -> worker : HTTP request
worker -> dialer : initiate_call(&request)
dialer -> dialer : URL + call_form(...)
dialer -> fetch : execute → send(request, policy, mode)\n!Send future
fetch -> carrier : HTTPS POST
carrier --> fetch : response (JSON)
fetch --> dialer : HttpResponse
dialer -> dialer : status check, json()
dialer --> worker : TransportResult<DialReceipt, _>
worker --> event : response with the call SID
@enduml