Architecture

┌──────────────┐  SPA OIDC (PKCE)  ┌─────────────────┐
│  UI :8080    │ ───────────────►  │  Keycloak IdP   │
│  React       │ ◄── access_token ─│  MFA / federated│
└──────┬───────┘                   └─────────────────┘
       │ Bearer JWT
       ▼
┌──────────────┐   enqueue    ┌──────────────────────────────┐
│  API :8081   │ ───────────► │  Postgres jobs (SoT)         │
│  Hono        │              │  + optional NATS/Rabbit/Pulsar│
└──────┬───────┘              └──────────────┬───────────────┘
       │ sessions / findings                 │ claim
       ▼                                     ▼
┌──────────────┐                    ┌─────────────────┐
│  Postgres    │                    │  Workers        │
│  product SoT │                    │  (HPA / KEDA)   │
└──────────────┘                    └────────┬────────┘
                                             │
              ┌──────────────────────────────┼────────────────────────┐
              ▼                              ▼                        ▼
     Graph MCP (stdio in worker)     Model router              Sandbox / Prove
     Neo4j · Janus · GraphQLite      OpenAI · Anthropic · SpaceXAI   local · docker · k8s

Layer	Role
UI	Product surface; browser holds OIDC tokens
API	Auth, sessions, webhooks, enqueue
Worker	Orchestrator, specialists, judge, SCM publish
Graph	Structural intelligence via MCP (embedded in workers)
Queue	Postgres by default; optional broker for KEDA wake-up only

Data plane

• Postgres — sessions, findings, jobs, learning, users/orgs (when not pure IdP shadow)
• Workspace disk — SCM clones under {STEW_WORKSPACE_DIR}/{orgId}/{sessionId}
• Graph store — shared Neo4j/Janus recommended; namespaced by product orgId

Trust boundaries

• Tenant org admins manage members, connectors, models, policy
• Platform operators manage install-wide runtime, license, queue recovery, graph rebuild
• Workers should not share unjailed shells across orgs — see Multi-tenant workers

Deep dive: How a review works