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NBS Workshop

Hub-and-spoke routing

The same platform, viewed as a routing hub. User Management (apps/user-management on port 3001) sits at the center — every client request and every backend dispatch passes through it.

User Management is the central gateway hub. Six client surfaces fan in on the left. Six backend destinations fan out on the right.

The hub — User Management Core

Four sub-tiers inside User Management:

Sub-tierWhat it does
InboundIngress (Cloud Run HTTPS · Tauri HTTP) → Auth middleware (JWT validation, session check via apps/auth) → Webhook receivers (/webhook/whatsapp, /api/billing Stripe, OAuth callbacks)
UM Core (the dispatcher)Route Dispatcher (files · models · billing · plugins · skills · microapps) · Agent Proxy (cloud: spot-VM proxy, local: Tauri sidecar) · Target Resolution (provisioner/spot-vm.ts)
OutboundAgent routes → Agent API (4000) · Direct routes → handled by UM itself · SSE pass-through → /api/events/company/:id
Adjacent servicesWeb SSR (3000) · Auth Service (3002) · Tauri Sidecars (local-mode only — UM + Agent API in-process)

Why a single dispatcher

Without a hubWith UM as the hub
Each client knows N backend URLsEach client knows one URL
Auth implemented N timesAuth implemented once at the gateway
Webhooks land in random placesAll webhooks land in one Express dispatcher
Local vs cloud mode = different code pathsSame gateway contract; only the target URL changes
Spot-VM provisioning leaks into clientsProvisioning is hidden behind the proxy

Same gateway contract, both modes

The diagram’s most important line is the one at the bottom of the hub:

In cloud mode UM runs on Cloud Run and proxies to spot-VM agent containers. In local mode UM runs as a Tauri sidecar and proxies to the local Agent API. Browser code is identical — only the target URL changes.

This is what makes Tauri Desktop + Cloud Run two faces of one product. The hub abstracts the deployment.

The six clients and six destinations

Clients (fan-in):

  • Web Users — Browser (Next.js, apps/web · port 3000, SSR + static)
  • Tauri Desktop — macOS · Win · Linux (WebView + sidecars, local-mode)
  • iOS App — apps/ios native, talks to cloud UM over HTTPS
  • Internal Admin — Ops console (deploy · health · cost · routines)
  • Chat Users — WhatsApp · Telegram (message-driven, never see UI)
  • Phone Caller — Voice bridge (SIP/WebRTC in, Gemini Live realtime)

Backend destinations (fan-out):

  • Auth Service — apps/auth · 3002 (identity, tokens, refresh, sessions)
  • Agent API · Orchestration — apps/api · 4000 (heartbeat · invoker · runs · routines · issues)
  • Agent API · Channels — registry · dispatch (WhatsApp Baileys, Telegram grammy)
  • Direct APIs — files · models · billing · plugins · skills · OAuth (handled by UM directly)
  • External Providers — LLM · OAuth · Voice · Stripe · Firebase · GCS
  • Data Tier — Postgres/SQLite · Filestore/local FS · Secrets keychain