Container View

The container view (C4 Level 2) shows the major deployable units within the PSI system and how they interact.

PSI System Containers

PSI Frontend

The frontend is built around the Structure + Feature plugin architecture:

• 18 structures define content types and screens (16 core + 2 ZDF: Question, Profile, Article, Topic, Admin, etc.)
• 60+ features extend structures via config slots (core ~25, ZDF 23, CBC/RC 8, SRG 3)
• Design system with 50+ reusable components based on the PSI Figma

PSI Backend (Cloud Functions)

PSI Backend (Standalone)

Both deployment modes share the same Hono application created by createApp(). The request flow is:

1. Hono routes match /:componentId/:apiId or /api/:componentId/:apiId
2. CORS middleware and context injection (authAdapter, databaseAdapter, modules)
3. Create a ServerStore scoped to the request's instance and user
4. Check admin authorization for admin-only functions
5. Dispatch to matching module's publicFunctions or adminFunctions
6. Batch all writes and commit after the function completes
7. Return JSON, HTML, text, or redirect response

Firebase Realtime Database

Primary data store. Data is organized as:

silo/{siloKey}/
  module/{moduleKey}/                 # PRIVATE module data (server-only)
  module-public/{moduleKey}/          # PUBLIC module data (all users can read)
  module-user/{userId}/{moduleKey}/   # USER_GLOBAL data (per-user read/write)
  module-user-read/{userId}/{moduleKey}/ # USER_READ data (user reads, server writes)
  structure/{structureKey}/
    instance/{instanceKey}/
      collection/{typeName}/{objectKey}  # Per-instance collections (comments, etc.)
      global/                            # Server-only instance properties
      global/features/                   # Enabled features dictionary

MongoDB (Alternative)

An alternative database backend available via the adapter pattern. Uses compound-prefixed keys for data locality:

Moderation Service Containers

The moderation service is a standalone microservice that can operate independently of the main PSI backend. It has its own adapter layer (database, email, LLM) mirroring the main server's pattern. Key capabilities:

1. Two-pass moderation: Light model (gpt-4o-mini) for initial screening, heavy model (gpt-4o) for flagged content
2. Perspective API: parallel toxicity scoring
3. Blocklist management: add/remove/check terms against a blocklist
4. AT Protocol (Bluesky): create posts, reply, search, and manage profiles on the Bluesky network
5. Dual database: Firebase Firestore (primary) or MongoDB 7 (alternative via adapter)

Publisher Integration Containers

Next Level

Zoom into the Component View to see the internal structure of the PSI backend and frontend.