# Documentation


- **Getting Started**
- [Introduction](/docs): TypeScript and PostgreSQL event history for agent workflows and domain applications, with typed aggregates, replay, projections, snapshots, and an outbox.
- Playbooks
  - [Agent History, Replay & Audit](/docs/playbooks/ai-agent-deterministic-memory-and-audit): Record agent workflow events in TypeScript and PostgreSQL, reconstruct earlier state, and understand the limits of replay, privacy, and external effects.
  - [Aggregate Design & Stream Boundary Playbook](/docs/playbooks/aggregate-design-and-stream-boundaries): Architectural blueprints and decision frameworks for aggregate sizing, stream partitioning strategies, concurrency boundaries, and read-side optimization in Alvyn and PostgreSQL.
  - [Event Streaming & Resilient Consumer Playbook](/docs/playbooks/sse-and-consumer-scaling): Architectural blueprints and step-by-step implementation for event-driven systems. Stream events via Server-Sent Events (SSE), recover seamlessly with W3C Last-Event-ID, scale consumer fleets, and evaluate message brokers.

- **Features**
- [Aggregates](/docs/aggregates): Define type-safe event-sourced aggregates with full TypeScript inference, encryption, and schema evolution.
- [Snapshots](/docs/snapshots): Define event-backed snapshots for derived state without a separate snapshot table.
- [Subscriptions](/docs/subscriptions): Fan-out event subscriptions with historical catch-up, live tailing, filtering, resumable cursors, GraphQL subscriptions, and SSE endpoints.
- [Transactional Outbox](/docs/outbox): Atomically publish domain events to external message brokers (Kafka, NATS, RabbitMQ) with at-least-once delivery guarantees.
- [Projections](/docs/projections): Build read-optimized query models from the global event stream with atomic checkpoints and transactional consistency within PostgreSQL.
- [GDPR & Data Privacy](/docs/crypto-shredding): Architectural patterns for handling personal data and GDPR Article 17 erasure requests in append-only event stores.
- [Schema Evolution](/docs/schema-evolution): Read-time upcasters that transform old event schemas into newer versions without modifying stored data.

- **Performance & Scaling**
- [Production Load Testing](/docs/load-testing): Run Alvyn's deterministic HTTP load profiles and interpret their performance and production-readiness results.

- **Examples**
- [Full-stack Example](/docs/full-stack-example): A Vite, Nitro, React, Apollo, GraphQL, and PostgreSQL example using live Alvyn subscriptions.

- **Reference**
- [API Reference](/docs/api-reference): Complete reference for the EventStore class, all exported types, and error classes.
- [Database Schema](/docs/database-schema): PostgreSQL table structure for the event store — events, event-backed snapshots, outbox, crypto keys, and projections.

- **AI Docs**
- [llms.txt](/llms.txt)
- [llms-full.txt](/llms-full.txt)