TWS is running but not accepting the connection

Scalpel found the program (the port answered) but the handshake that follows never completed. That is almost always a setting or a question waiting inside TWS, not a network problem.

TWS is running on port 7497 but is not accepting the connection. In Configure > API > Settings, enable the API socket and allow Scalpel when it asks.

With IB Gateway the banner reads "IB Gateway is running on port 4001 but is not accepting the connection. In Configure > Settings > API, enable the API socket and allow Scalpel when it asks." The status bar pill keeps reading Disconnected while Scalpel retries.

TWS is running on port 7497 but is not accepting the connection. In Configure > API > Settings, enable the API socket and allow Scalpel when it asks.

D1

D2

IBKRDisconnected: session endedv1.12.6 (4f2c9a1)

Fix it

1. 01

   Look for a waiting question in TWS

   Switch to TWS or IB Gateway and look for a small window asking whether to accept an incoming API connection. It can open behind other windows. Accept it. Scalpel opens several connections (quotes, depth, orders, scanner), so it may ask more than once.

2. 02

   Enable the API socket

   Open the API settings: in TWS, Configure (the gear, or File > Global Configuration) > API > Settings; in IB Gateway, Configure > Settings > API > Settings. Tick Enable ActiveX and Socket Clients 1.

   Global Configuration (simplified)

   APISettingsPrecautions

   Enable ActiveX and Socket ClientsRead-Only APISocket port7497Allow connections from localhost onlyTrusted IPs127.0.0.1

   1234

3. 03

   Trust this computer

   Under Trusted IPs, click Create and add 127.0.0.1 4. TWS then stops asking every time Scalpel connects. Leave Allow connections from localhost only ticked: Scalpel runs on the same computer.

4. 04

   Untick Read-Only API

   Read-Only API 2 does not stop the connection, but it makes TWS refuse every order Scalpel sends in LIVE. Untick it now so you do not meet it mid-trade (guide 13.5).

5. 05

   Click OK and wait a few seconds

   Click OK (or Apply and OK). Scalpel retries by itself; the pill turns green and reads Connected. No restart of Scalpel is needed.

Still not accepting?

• Another copy of Scalpel is open, or another program uses Scalpel's API client ids. Close it. The status bar may read "Disconnected: TWS refused the connection (client id in use?), retrying".
• IB Gateway or TWS has just logged in and is still loading. Give it 30 seconds.
• A dialog is open in TWS, such as a message after login. Close it; TWS can hold API connections until it is dismissed.
• The port belongs to something else. The banner checks only that the port answers. If you changed TWS's port, make sure no other program uses the same number.
• Restart TWS or IB Gateway after changing API settings if nothing else works. Scalpel reconnects by itself when it comes back.

For the full TWS and IB Gateway setup, see guide 1.5. For other banner messages, see guide 13.1.

Questions

Where is Enable ActiveX and Socket Clients?

In TWS: Configure (or File > Global Configuration) > API > Settings. In IB Gateway: Configure > Settings > API > Settings.

Why does TWS keep asking me to accept the connection?

Because 127.0.0.1 is not a trusted IP. Add it under Trusted IPs in the API settings and TWS stops asking.

Should Read-Only API be on or off?

Off, if you want to place LIVE orders from Scalpel. With it on, Scalpel connects and shows data but every order is refused.

Do I need to restart Scalpel after changing TWS settings?

No. Scalpel retries the connection on its own every few seconds.