TWS historical-data pacing: stop repeated requests

Quick answer

Historical-data pacing limits how quickly an app can request bars. Repeating the same request at once can make the problem worse. Identify the request pattern and apply the current rule for its bar size and data type.

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Step by step

1 In a TWS chart, open Edit → Chart Parameters. Note Time period and What to show. For an API query, save the actual contract, bar size, dates and time from the app log; chart settings do not control the app request.
2 Check whether the client is repeating the same requests or opening many charts at once.
3 Pause duplicate queries and ask the client to queue requests at a supported rate.
4 Reduce history you do not need and reuse saved data where suitable. To review a recorded API log, use Help → Troubleshooting → Diagnostics → API Logs. An empty list means there is no saved log to check.
5 Test a small request sequence and watch for another pacing message.

A practical example

An app opens twenty charts and asks for the same old bars each time you switch tabs. That may waste requests. A better request plan reuses data already fetched and spaces out the new work. To test the cause, use one chart and one small range. If that works while the full burst fails, preserve the two logs for the app provider. Do not keep repeating the burst just to see whether the next try passes.

Illustrative scenario, not a record of a trade placed during this review.

Screen reference

TWS Chart Parameters showing time period, data type, bar type, volume, VWAP and session controls — Compare Time period and What to show first. Additional Data and Features contains Volume and VWAP of the bar. Chart Time Options contains the extended-hours and user-time-zone controls. The dialog was closed with Cancel; no settings were applied. Captured in TWS paper mode on 3 October 2026. Open the image for full size.

TWS 30-second candlestick chart with the Edit menu and time axis — This chart is an example of the chart window. It is not evidence of a live feed, a particular API request, or a trading signal. Use Edit → Chart Parameters to inspect its inputs. Captured in TWS paper mode on 3 October 2026. Open the image for full size.

TWS View Logs dialog with View Logs, Export Logs and Export Today Logs buttons — This session has no recorded API logs in the list, so export buttons are disabled. Enable API logging before the event you need to capture. No log was exported or uploaded for this screenshot. Captured in TWS paper mode on 3 October 2026. Open the image for full size.

How to confirm the result The needed queries should complete without repeated pacing violations.

Mistake to avoid

A faster machine or new socket port does not remove server-side request limits.

Common questions

Do all bar sizes use the same limits?

No. Read the rule for the requested data, especially small bars.

Should I retry continuously until it works?

No. A retry loop can keep the app over its limit.

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Financial and information disclaimers

Financial disclaimer

These guides explain software. They are for education, not financial, investment, tax, or legal advice. No example is a suggestion to buy or sell a product or use a trading strategy. Trading can lose money, including all funds you put at risk. With margin, futures, short sales, or some options, losses can exceed your starting funds. Automation can fail, send duplicate orders, or act late. Stops do not guarantee a fill or a price. Review your orders and positions, and seek advice from a qualified professional for your own needs. Paper trades, examples, and past results do not predict live results or promise a profit.

Information disclaimer

This is general help based on the sources and check date shown on the page. Screens, settings, fees, data access, and product support can change or differ by app version, account, country, and broker. The content may contain errors or become out of date; accuracy, completeness, and continuous service are not guaranteed. Check current broker and app instructions before acting. Screenshots show where controls are; they do not prove that an order test passed. This guide does not replace broker terms or risk notices. References to IBKR and TradingView identify their products and do not imply their endorsement of this guide.