Read-only broker context
IBKR Paper TWS setup and troubleshooting for Lumiere
Use a clearly identified simulated account, keep API access read-only, and treat paper fills as practice—not evidence of live execution quality. Lumiere’s V1 connector reads market context locally and does not transmit customer orders.
Direct answer
How do you connect Lumiere to IBKR Paper TWS?
Log into a session that visibly identifies itself as paper trading, enable socket API clients in TWS, keep the API in read-only mode, use the paper-trading socket port configured for your installation, start the versioned Lumiere Local Connector, and confirm its local health check before opening the app.
Before connecting: verify the account is simulated
IBKR states that the paper interface clearly indicates when a simulated account is in use. If that indication is absent, the session may be a production account and filled trades can create real obligations. Existing individual account holders can generally select production or paper trading when logging into TWS, while some account structures and regions require separate paper credentials.
Platform source: IBKR: About Paper Trading Accounts, last updated January 30, 2026 when reviewed.
Connection checklist
- Open IBKR Paper TWS.Confirm the interface visibly identifies the account as simulated before changing any API setting.
- Enable socket clients.Use the API settings in TWS and limit access to the local machine unless you have a separately reviewed network design.
- Keep Read-Only API enabled.Lumiere V1 needs quotes, bars, daily volume, and connection status. It does not need customer order transmission.
- Confirm the paper socket port.The Lumiere beta defaults to port 7497 for Paper TWS. If TWS uses a different configured port, the connector and TWS must match.
- Start the versioned connector.Download the current artifact from the authenticated Lumiere account page and run it locally.
- Check local health.Confirm the connector reports ready before relying on IBKR-labeled context in the Lumiere app.
- Verify source labels in Lumiere.If broker context is unavailable, Lumiere may label another provider or unavailable state. Do not assume fallback data came from IBKR.
Paper trading limitations that matter
Simulated fills
Paper trades do not execute on an exchange or settle at a clearing house. Simulated prices use real market prices and sizes.
Top-of-book model
IBKR says paper fills are simulated from the top of the book without deep-book access.
Complex orders
Stops and other complex order types are always simulated and may behave differently from production.
Unsupported behavior
Some order types, combo behavior, options penny fills, mutual funds, and partial market-order handling have documented limitations.
Because of those limitations, a successful paper fill is evidence that a workflow was practiced—not proof that the same order would fill at the same price or in the same way live.
Troubleshooting
- The connector cannot reach TWS
- Confirm TWS is running, socket clients are enabled, the host is local, and the configured ports match. Restart the connector only after verifying the account is still paper.
- The account looks live
- Stop. Do not continue until the TWS interface clearly identifies the simulated account. Lumiere’s read-only control does not change which account is open in TWS.
- Quotes are missing or delayed
- Check TWS market-data permissions, subscriptions, account configuration, and connection status. IBKR notes that paper trading permissions and market-data configuration follow the associated account.
- Lumiere shows a fallback source
- Read the source label and freshness timestamp. Treat broker-aligned context as unavailable until the IBKR lane reports ready.
- A paper fill differs from expectations
- Compare the behavior with IBKR’s documented simulator limitations. Do not infer that production execution is broken—or that it would match the simulation.
Use IBKR’s native pre-order checks too
IBKR TWS can preview commissions, margin impact, and order details before transmission, and Risk Navigator can compare current and hypothetical portfolio risk. These native tools complement a Lumiere review; neither removes market or execution risk.
Platform source: IBKR TWS: Check Margin Pre-Order.
Platform source: IBKR TWS: Check Risk Pre Order.
Connector details