Introduction

SnelDB is a lightweight, high‑performance database for immutable events. You append facts, then filter or replay them—quickly and reliably.

What it is

• Store: append events with a type, context_id, timestamp, and payload
• Query: filter by event type, context, time, and conditions
• Replay: stream events for a context in original order

DEFINE payment FIELDS {"amount":"int","status":"string"}
STORE payment FOR user-123 PAYLOAD {"amount":250,"status":"verified"}
QUERY payment WHERE status="verified"
REPLAY FOR user-123

Why it exists

General-purpose databases and queues struggle with large, evolving event logs. SnelDB is built for:

• Immutable, append-only data
• Fast filtering at scale (columnar + pruning)
• Ordered replay per context
• Minimal ops overhead

Key features

• Append-only storage (perfect audit trails; predictable recovery)
• Simple, human‑readable commands (JSON‑native)
• Fast queries at scale (shards, zones, compaction)
• Replay built in (time‑travel debugging, sequence modeling)
• Flexible schemas (strict validation; optional fields)
• Lightweight & safe (Rust; embeddable; no GC)

Who it’s for

• Product analytics and auditing
• ML pipelines on event sequences
• Operational debugging and timeline reconstruction