Changelog

Release notes for the PaperBroker Python Client

v0.2.4 Latest

March 17, 2026

Introduces SQLite-based order persistence — solving a critical issue where active order IDs are lost if the program crashes or is terminated unexpectedly. Orders are now saved to SQLite on every lifecycle event and can be recovered on restart.

Added

order_store_path constructor parameter — enables SQLite persistence (default: "orders.db", set None to disable)
recover_pending_orders() method — reloads active orders from SQLite and rehydrates in-memory state so cancel_order() works immediately after restart
New OrderStore module (paperbroker/session/order_store.py) with WAL journal mode, atomic commits, and thread-safe access
Example 02_cancel_order.py updated to demonstrate crash recovery flow

Design

Order state persisted at 3 critical moments: place_order(), execution report received, and every status change
Fail-safe design — SQLite errors are logged but never crash the trading flow
100% backward compatible — no breaking changes, no new dependencies (sqlite3 is stdlib)

Recovery Usage

client.connect()
client.wait_until_logged_on(timeout=10)

# Recover orders from previous session
pending = client.recover_pending_orders()
if pending:
    for order in pending:
        print(f"  {order['cl_ord_id']}: {order['side']} "
              f"{order['qty']}x {order['symbol']} @ {order['price']}")
        client.cancel_order(order["cl_ord_id"])

Backward Compatibility

Scenario	Behavior
Existing code, no changes	Works — persistence auto-enabled with orders.db
order_store_path=None	Memory-only mode, identical to v0.2.3
SQLite file missing or corrupt	Degrades to memory-only, logs warning
SQLite write fails mid-session	Error logged, order flow continues

v0.2.2 Stable

January 2026

Initial public release with FIX 4.4 trading support, event-based API, market data subscriptions, and REST integration for account management.

Features

FIX 4.4 protocol support via QuickFIX engine
Event-based order management (place, cancel, track)
Market data query and real-time subscription (Redis & Kafka)
Multi sub-account support with cross-matching
REST API integration for portfolio, transactions, and cash balance
11 example scripts covering all major use cases