Architecture And Lifecycle

1. Integration Surface

• Zoom Contact Center App (Zoom client embedded webview).
• Web SDK/Campaign SDK on external sites.
• Android/iOS native SDK.

2. Engagement State Layer

• Current engagementId.
• Engagement status (start, hold, resume, end).
• Engagement-scoped draft data.

3. Channel Service Layer

• Chat.
• Video.
• ZVA.
• Scheduled Callback.

4. Persistence Layer

• Transient per-engagement state cache (frontend local storage or backend session store).
• Optional backend persistence for long-running workflows and compliance logging.

Canonical Lifecycle

1. Initialize context.
2. Determine active engagement context.
3. Build/init channel service/client.
4. Register callbacks before launching UI.
5. Start channel view.
6. Process status/context events.
7. End and cleanup.

Context-Switching Contract

• Treat engagementId as the primary state key.
• Never assume a single engagement in memory for messaging channels.
• Restore state on each engagement context change.
• Clear or archive engagement state only when end-state logic is complete.

Event-Driven Contract

• Do not poll as a primary strategy.
• Subscribe early and keep handlers idempotent.
• Handle out-of-order or repeated events safely.

Campaign Mode Pattern

1. Fetch campaigns with campaign API key.
2. Pick channel from translatedCampaignChannels.
3. Create channel item with useCampaignMode=true.
4. Launch service UI.
5. Release conflicting channel services when switching channels.

Security and Identity

• Use explicit user/session identity refresh paths (authorize, getAppContext) for Contact Center app scenarios.
• For PWA flows, do not depend on x-zoom-app-context header.
• Keep OAuth and app context decryption on backend where possible.