Why Qazna?

Qazna is to financial accounting what PostgreSQL is to data storage.

You wouldn't write your own B-Tree implementation to store user data. You shouldn't write your own UPDATE accounts SET balance = ... logic to manage financial data.

The Problem: The "Ad-Hoc Ledger" Trap

Most fintechs and marketplaces start the same way:

1. Add a balance column to a users table.
2. Write a simple SQL transaction to move money.
3. Scale up.

Then the problems start:

• Race Conditions: Two concurrent transfers overdraw an account.
• Lost History: "Why is this user's balance -50?" You can't replay the history to find out.
• Drift: The sum of all user balances + the bank account balance doesn't match. Money has evaporated.

The Solution: A Deterministic Standard

Qazna is a Ledger Runtime built on the Open Ledger Runtime Standard. It provides:

1. Double-Entry by Default: Every transaction must balance. Credits = Debits. Zero-sum. Always.
2. Immutable Append-Only Log: You never update a balance in place. You append a state transition. The balance is a derived view of history.
3. Strict Serialization: Qazna queues and applies operations deterministically. If you replay the same log 10 years later, you get the exact same state.

Startup vs. Standard

Qazna was born from a realization: building a new "global settlement network" (Startup path) is political and hard. Building a better tool for engineers to build their networks (Standard path) is pragmatic and necessary.

• Linux didn't replace Microsoft by selling an OS; it replaced it by being the infrastructure everyone built the internet on.
• Qazna aims to be the infrastructure everyone builds finance on.

When to use Qazna

Use Case	Status Quo	With Qazna
Fintech Wallets	Complex SQL queries, manual locks	POST /transactions (guaranteed atomic)
Marketplaces	"Where did that $5 go?"	Traceable flow from Buyer -> Escrow -> Seller
Clearing	Spreadsheets and disputes	shared, verifiable audit log

4. Atomic Multi-Asset Settlement (PvP)

Pain Point: Sending money internationally often involves "Herstatt Risk" — you send EUR, but don't get USD back because the counterparty failed mid-flight.

Qazna Solution: Qazna supports Atomic Swaps. You can bundle multiple transfers (A->B and B->A) into a single transaction ID. The engine guarantees that either both happen, or neither happens.

• No "half-completed" states.
• No need for escrow services.
• Mathematical trust.

Next Steps

• Read the Standard: Understand the rigorous math behind the model.
• Try the Quick Start: Spin up a ledger in 5 minutes.