Interactive Brokers Enhances TWS API with Overnight Trading Condition Support

According to FX News Group, Interactive Brokers has rolled out an update to its Trader Workstation (TWS) API that introduces a new conditionsIncludeOvernight field on the Order object, letting conditional orders evaluate overnight trading sessions. The change closes a gap where conditional logic previously had no clean way to reference overnight session data without external workarounds.

Order object: conditionsIncludeOvernight

The field is additive and sits alongside existing condition attributes on the Order object. When populated, it tells the conditional engine that overnight trading sessions count as valid evaluation windows for the trigger criteria. Orders that do not reference the field continue to behave exactly as before — no migration step, no message contract change for legacy clients. For systematic traders running time-based or price-based triggers across the full 24-hour cycle, this removes a class of silent misses where overnight bars were excluded from condition matching.

.proto cleanup and open-source context

The release also expands descriptions across all fields in the protocol buffer (.proto) files. Anyone generating client stubs from the schema gets inline documentation, which reduces lookup overhead during integration and cuts the back-and-forth with the reference docs. The update lands in the same window as Interactive Brokers' recent decision to release the TWS API as open source under the GNU General Public License (GPL). Developers now have direct visibility into the source tree the vendor ships, which makes field-level changes like this easier to audit rather than relying solely on release notes.

Contract Details: Settlement Type

A separate addition introduces a new Settlement Type field inside Contract Details. Users can now read settlement metadata directly off the contract object instead of querying a separate reference or maintaining a local mapping table. That streamlines post-trade reconciliation logic and removes one round-trip from contract-intake pipelines. The API retains its existing runtime coverage — C++, C#, Java, Python, ActiveX, RTD, and DDE — alongside prebuilt libraries that target TWS UI automation or fully custom front ends. Higher-volume clients can still route through the Client Gateway to keep bandwidth pressure down on the primary TWS session.

Verdict

Additive change. No breaking modifications. Conditional order handling now covers overnight sessions natively, and the surrounding schema plus contract metadata have gained small but useful upgrades.