tigerstar 0.1.1

Double-entry ledger engine with pluggable storage backends

TigerStar

A double-entry ledger engine with pluggable storage backends.

Features

• Double-entry bookkeeping — every transfer debits one account and credits another
• Two-phase transfers — reserve funds (pending), then post or void
• Linked transfers — atomic chains that all succeed or all fail
• Balance constraints — prevent overdrafts with account flags
• Multi-currency — separate ledgers per currency with configurable precision
• Financial reporting — trial balance, balance sheet, general ledger
• Storage adapters — swap between Firestore and PostgreSQL without changing application code
• Concurrent-safe — row-level locking (Postgres) or optimistic transactions (Firestore)

Install

pip install tigerstar[postgres]    # PostgreSQL only
pip install tigerstar[firestore]   # Firestore only
pip install tigerstar[all]         # both backends

Quick Start

With Firestore

from tigerstar import TigerStar, FirestoreStorage

storage = FirestoreStorage(credentials_path="path/to/firebase-adminsdk.json")
engine = TigerStar(storage=storage)

With PostgreSQL

from tigerstar import TigerStar, PostgresStorage

storage = PostgresStorage(dsn="postgresql://user:pass@localhost:5432/dbname")
storage.migrate()
engine = TigerStar(storage=storage)

Create a ledger and move money

from tigerstar import Ledger, Account, AccountType, AccountFlags, Transfer, TransferCode

ledger = Ledger(currency="TZS", precision=0, max_transfer_amount=10_000_000)
engine.create_ledger(ledger)

cash = Account(ledger_id=ledger.id, code=AccountType.ASSET)
user = Account(
    ledger_id=ledger.id,
    code=AccountType.LIABILITY,
    flags=AccountFlags(debits_must_not_exceed_credits=True),
)
engine.create_accounts([cash, user])

engine.create_transfers([
    Transfer(
        debit_account_id=cash.id,
        credit_account_id=user.id,
        ledger_id=ledger.id,
        amount=50000,
        code=TransferCode.PAYMENT,
    ),
])

Storage Adapters

Adapter	Database	Best For
FirestoreStorage	Google Cloud Firestore	Serverless, zero-ops, auto-scaling
PostgresStorage	PostgreSQL	Financial-grade ACID, SQL flexibility, cost control

Both adapters implement the same interface — swap one for the other with zero application changes. See docs/adapters.md for connection pooling, migrations, and writing custom adapters.

Documentation

• Usage Guide — ledgers, accounts, transfers, reporting
• Storage Adapters — setup, configuration, custom adapters