TWS API connection approval popup: what to check

Quick answer

A TWS connection popup asks whether to accept an API client. Confirm the source belongs to the app you just opened. If no connection is expected, do not accept it. A missing approval can leave an app waiting.

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

Step by step

1 Check the source address displayed in the popup against the machine that runs your app.
2 If it is your expected client, accept that connection. If it is unfamiliar, decline and investigate.
3 Open API → Settings and review localhost and Trusted IPs for the intended setup.
4 Add only an address you have verified if you want future connections from it to be accepted.
5 Reconnect the app and check that the account it receives is correct.

A practical example

You start your own desktop app and a TWS prompt appears at the same time. Check the source shown in the prompt against the machine you chose. If it matches, you can approve that planned link. If you did not start an app and do not know the source, stop and ask who owns it. The goal is to let your chosen app connect, not to approve every request that reaches TWS.

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

Screen reference

Lower TWS API Settings showing localhost-only and Trusted IPs controls — The localhost-only box is selected and the Trusted IPs list is empty in this paper session. These are observed settings, not instructions to allow a remote address. Captured in TWS paper mode on 3 October 2026. Open the image for full size.

How to confirm the result The connection should complete without an unexplained approval request on each attempt.

Mistake to avoid

Approving an unknown connection is not a troubleshooting shortcut. Trust applies to the source, not just to the name an app displays.

Common questions

Will every denied address show a popup?

No. IBKR notes that untrusted IPs may be denied without a prompt.

Do I need to allow remote access for two local apps?

Usually no. Confirm both programs run on the same computer.

How to enable the TWS API for PickMyTrade TWS error 502: cannot connect to the API TWS and IB Gateway ports: paper versus live TWS error 507 or EOF: the API socket closed

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.