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Phase 10: Real-Time Vision

Document Type: Vision Statement
Phase: 10 - Real-Time Subscriptions
Status: Active

Goal

Enable real-time event subscriptions over WebSocket, allowing clients to receive database changes as they happen, while preserving AeroDB's determinism guarantees where possible.

Philosophy

Determinism Boundary

AeroDB introduces a clear determinism boundary in Phase 10:

Layer Determinism Guarantee
WAL Deterministic Same writes → Same log
Event Log Deterministic Same WAL → Same events
Dispatcher Non-Deterministic Best-effort delivery
Client Non-Deterministic Must handle out-of-order

Key Insight: The Event Log is the last deterministic layer. Clients see a projection that may differ due to network conditions.

Core Principles

  1. Event Log as Source of Truth - Database events derived from WAL
  2. Explicit Non-Determinism - Dispatcher makes no ordering guarantees
  3. RLS-Filtered Delivery - Events filtered per-user before dispatch
  4. Fail-Open for Delivery - Missed events don't crash the system
  5. Explicit Subscriptions - No implicit broadcast

Non-Goals

  • Exactly-once delivery (at-least-once is acceptable)
  • Global ordering of events across all clients
  • Guaranteed delivery (clients must handle reconnection)
  • Persistent event history (events are ephemeral)

Success Criteria

  1. Clients receive events within 100ms of commit (p95)
  2. RLS filtering applied to all events
  3. System handles 10k concurrent WebSocket connections
  4. Clean reconnection with resume from sequence number