Charles Schwab and Third-Party Apps: API, thinkorswim, and Connections

By Sam Davila on 2026-07-10 - 2 min read

Charles Schwab is now the largest retail brokerage in the United States, and after absorbing TD Ameritrade it also inherited the most beloved retail trading platform (thinkorswim) and one of the most-used broker APIs. Third-party connectivity is well supported: Schwab offers OAuth-based API access that many portfolio and trading tools have adopted.

Schwab in one paragraph

Schwab covers essentially everything: stocks, ETFs, options, futures (via thinkorswim), managed portfolios, retirement accounts, and banking. It suits investors who want one large, stable institution, and traders who want thinkorswim's charting and options analytics without a specialist broker.

The TD Ameritrade inheritance

When TD Ameritrade folded into Schwab, its developer ecosystem migrated too: the old TDA API was retired and replaced by Schwab's own API program. If you used apps that connected to TD Ameritrade, those connections now run against Schwab, and any app still advertising "TD Ameritrade support" is describing the past. thinkorswim itself lives on as Schwab's active-trader platform.

How third-party access works

  • OAuth authorization: you approve each app on Schwab's own login pages, and access is granted via revocable tokens with defined scopes for account data, market data, and trading.
  • Revocation: connected applications are listed in your Schwab security settings, where access can be removed per app at any time.

In a multi-broker setup

Schwab is often the anchor account: retirement and long-term holdings there, with a second broker for a specific need (crypto, futures pricing, a particular tool). That split is exactly where a combined view earns its keep, since your true concentration lives across both. Connecting Schwab to Sentient Logic brings the anchor account into the same AI-analyzed picture as the rest. Feature availability varies by broker and account type.

Educational content, not financial advice. Broker capabilities change; verify current details with the broker.