TWS error 100: too many API messages

Quick answer

Error 100 indicates the API client is sending messages too quickly. Stop a retry loop or request burst and have the app control its request rate. More computer memory does not fix an excessive message stream.

Educational software guidance. Trading involves risk. Read the financial and information disclaimers.

Step by step

1 Save the full app message first. To check a recorded TWS API log, open Help → Troubleshooting → Diagnostics → API Logs. Select its date and choose View Logs. If the list is empty, enable API logging before the next event.
2 Note the time the error begins and the client sending the requests.
3 Pause the source of repeated requests while preserving order monitoring.
4 Check for duplicated app instances, reconnect loops, or a large burst of quote subscriptions.
5 Ask the app developer to apply the current IBKR pacing rules and queue requests appropriately.
6 Resume with a small workload and monitor for recurring rate messages.

A practical example

An app loses its link, reconnects, and sends the whole watchlist over and over. That loop can create more traffic than the broker accepts. Pause the loop and save the log. A developer can then check the request rate and queue. More RAM will not change the number of messages the server allows. Keep order checks separate so you do not miss a fill while fixing the request stream.

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

Screen reference

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.

TWS Market Data Connections with farm purpose and status, plus API client columns — The observed services are connected and the API client list is empty. Use this panel to read current status; it does not reproduce a disconnect or prove an app handshake completed. Captured in TWS paper mode on 3 October 2026. Open the image for full size.

How to confirm the result The request stream should remain within the applicable pacing rules without repeated disconnects.

Mistake to avoid

Do not retry the whole failed batch at once. That can create another burst and obscure order state.

Common questions

Is order traffic part of the workload?

API message pacing is broader than historical-data requests alone.

Should I buy more RAM?

First correct request pacing; hardware changes do not remove protocol limits.

TWS error 200: contract not found or ambiguous TWS error 201: read the order rejection reason TWS error 202: why was the order cancelled? TWS delayed versus live data: how to tell How to enable TWS API logs for troubleshooting Export TWS logs for an IBKR support case

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.