Realtime Ledger API

Real-time double-entry ledger backend with strict consistency, idempotent writes, and streaming balance updates.

realtime-ledger is a minimal, high‑integrity double‑entry ledger API written in Go. It focuses on correctness, balance invariants, and a clean domain model while keeping the overall system small and easy to reason about.

Key features include:

Strict double‑entry validation (postings must balance per currency)
Balance safety checks preventing negative account states
Typed Money model with currency‑aware amounts
Pluggable storage layer (ships with an in‑memory store)
Lightweight REST API for accounts, balances, journals, and entries
Simple static‑token auth for quick testing

The goal of the project is to provide a clean reference implementation of a ledger core—small enough to understand end‑to‑end, but strict enough to serve as the foundation for more advanced financial systems. A Postgres‑backed store, idempotency keys, batching semantics, and full OpenAPI coverage are planned extensions.