deployquant-schwab

A broker adapter that lets DQengine trade a Charles Schwab brokerage account through the Schwab Trader API.

pip install deployquant-schwab

That is the whole setup on the DQengine side. The package registers itself, and dqengine brokers then lists schwab.

The adapter talks to the Trader API directly with Python's standard library. It needs no Schwab SDK and has no optional extras.

Credentials

You use your own Schwab developer app. Register an app in the Schwab developer portal. The redirect URI has to be HTTPS and has to be registered there. After you authorize the app, you have an app key, an app secret and a refresh token.

The adapter takes them as a creds mapping with app_key, app_secret, refresh_token and an optional account_number. When it refreshes the access token or looks up the account, it gives you back an updated mapping. It does not store credentials anywhere.

dqengine_schwab.oauth does the token refresh, which is one POST to Schwab's token endpoint. Your application runs the first two steps of the OAuth flow: building the authorization URL and exchanging the code.

Schwab's refresh tokens expire after seven days. When that happens the adapter raises BrokerAuthExpired, and the account owner has to authorize again.

No paper trading

Schwab has no paper environment, so this adapter trades real money. The adapter reports short selling as unsupported until it has been checked on a real account.

What the adapter has to get right

DQengine has a conformance test for broker adapters (tests/test_adapter_conformance.py), and this plugin has to pass it. The test checks three things. The adapter declares what it supports correctly: order types, time in force, short selling and extended hours. It refuses an unsupported order before anything is sent to the broker. Every broker error comes back as one of the exception types in dqengine.adapters.base.

Schwab rejects bad orders after accepting them. The order is created first and then shows up as REJECTED. The adapter keeps such an order visible until it reaches a final state.

License

PolyForm Shield 1.0.0. You can use, change and run it for anything, including trading your own money, except building a product or service that competes with DQengine or with the products built on it. See NOTICE.