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EvidentDB Documentation

Build audit-ready systems with immutable events, bi-temporal queries, and WebAssembly-powered state management
Quick Start Learn the Concepts

Clear Structure. Scalable Systems.

EvidentDB is a cloud-native event sourcing database built for businesses needing reliability. It clarifies complex systems and helps teams focus on building effective software.

Why EvidentDB?

Event Sourcing Native

Store all changes as immutable CloudEvents with atomic batch transactions and optimistic concurrency control.

Bi-Temporal Indexing

Query your data across two time dimensions - when events occurred and when they were recorded.

WebAssembly Runtime

Build custom State Views and State Changes using any language that compiles to WebAssembly.

Cloud Native Architecture

Deploy on AWS with DynamoDB, SNS, and Lambda, or run locally with the in-memory adapter.

Core Architecture

graph TB
    subgraph "Client Applications"
        A[JVM Client]
        B[REST API]
        C[gRPC]
    end

    subgraph "EvidentDB Platform"
        D[State Views]
        E[State Changes]
        F[Event Store]
    end

    subgraph "Storage Adapters"
        G[In-Memory]
        H[DynamoDB+SNS]
    end

    A --> D
    B --> D
    C --> D
    D --> F
    E --> F
    F --> G
    F --> H

Quick Example

Here's how simple it is to define a State View in EvidentDB:

// Define a State View with WebAssembly
export const orderView = defineStateView({
  name: "order-status",
  index: { stream: "orders/*" },
  decide: (state, event) => {
    switch (event.type) {
      case "order.created":
        return { ...state, status: "pending", items: event.data.items };
      case "order.shipped":
        return { ...state, status: "shipped", trackingId: event.data.trackingId };
      default:
        return state;
    }
  }
});

Get Started

Installation

Install EvidentDB locally or deploy to AWS

Quick Start

Build your first event-sourced application

Core Concepts

Understand event sourcing and bi-temporal data

API Reference

Explore the gRPC and REST APIs

Built for Scale

100% Event Durability
<10ms Write Latency
∞ Scalability

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