# Introduction

Welcome to the official documentation for **EntryTarget** — a high-performance, double-entry financial ledger backend.

This project is AI-ready and provides an [llms.txt](https://entrytarget.com/llms.txt) file for use by large language models.

## What is EntryTarget?

EntryTarget is a financial core designed to handle double-entry bookkeeping with high throughput, strong consistency guarantees, and built-in integrity validation. It is delivered as a container image accompanied by a per-customer signed license file, running on your own segregated AWS infrastructure (Fargate + RDS).

## Key Features

* **Double-entry bookkeeping** — every transaction creates balanced debit and credit journal entries
* **High throughput** — batch processing engine capable of thousands of transactions per second
* **Atomic transactions** — multi-entry transactions execute as a single unit
* **Idempotency** — configurable idempotency window with three-layer duplicate detection
* **Row-level integrity** — cryptographic hash on every row detects direct database tampering
* **Crash recovery** — built-in recovery mechanism for post-crash reconciliation
* **Ledger archiving** — client-controlled archival of historical ledger data
* **Observability** — Prometheus metrics with Grafana dashboards

## Architecture at a Glance

```
HTTP Client
    |  REST / JSON  (X-Api-Key + X-Api-Secret headers)
    v
Axum HTTP Server
    |  Auth middleware + Metrics middleware
    v
Domain Layer (business rules)
    |                        |
    v                        v
Write Path               Read Path
(Batch Engine)           (Read Replica)
    |
    v
RDS Master  --(replication)--> RDS Read Replica
```

All write operations flow through a batch engine for maximum throughput. All read operations go to the read replica, keeping the master reserved for writes.

## Design Principles

* **Stateless** — all state lives in the database. The server can be restarted at any time.
* **Integer amounts** — all monetary values are integers. You control decimal places (e.g., R$1.00 = 100).
* **No silent defaults** — every required configuration must be explicitly set. Missing values cause an immediate startup failure.
* **Closed scope** — the system does exactly what it needs to do, nothing more.

## Who Uses This?

EntryTarget is designed for companies that need a reliable financial core. Your application handles its own account/customer registry and uses EntryTarget solely as the financial backbone — managing balances, transactions, journal entries, and integrity.

## Getting Started

1. [Register on the Console](/docs/console/overview.md) and choose a plan
2. [Deploy your instance](/docs/console/deployment-options.md) (managed or manual)
3. [Set up credentials](/docs/console/credential-management.md)
4. [Create your first account](/docs/api-reference/accounts.md) and [execute a transaction](/docs/api-reference/transactions.md)

## Need Help?

Access the vendor Console at `https://console.entrytarget.com/` for support and instance management.


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