Diagnose order

Diagnose Order

Troubleshoot orders that aren't filling, were rejected or voided, or are behaving unexpectedly.

When to Use

An order isn't working as expected — not filling, got voided, shows an error, or produced unexpected results.

Prerequisites

Read-only diagnosis uses MCP read tools (no auth). Checking your own orders requires API key + private key.

Order Not Filling

1. Is the market active? Call context_get_market — check that status is "active". If "pending", "resolved", or "closed", the market is not accepting new trades.
2. Is your price competitive? Call context_get_orderbook — for a buy order, your bid must be at or above the lowest ask to fill immediately. For a sell, your ask must be at or below the highest bid.
3. Is the spread wide? If the bid-ask spread is large (>10 cents), your limit price may sit in the gap unfilled. Adjust closer to the opposite side, or use a market order.
4. Is there sufficient depth? Large orders need enough liquidity at your price level. Check the orderbook depth — if only 5 contracts are available at 45c and you want 100, most of your order will sit unfilled.
5. Resolution: Adjust price closer to the opposite side, reduce size, or switch to a market order for immediate fill.

Order Rejected or Voided

1. Get the order details — ctx.orders.get(orderId) and check status and voidReason.
2. Diagnose by void reason:

Void Reason	Cause	Fix
UNFILLED_MARKET_ORDER	Market order could not fill immediately	Reduce size, widen the cap price, or use a limit order
UNDER_COLLATERALIZED	Not enough USDC or inventory to support the order	Check context_get_balance, then deposit or adjust inventory mode
MISSING_OPERATOR_APPROVAL	Trading approvals are missing	Run context_account_setup
BELOW_MIN_FILL_SIZE	Executable remainder is below the minimum fill size	Increase size or use a limit order
INVALID_SIGNATURE	Private key doesn't match account	Verify CONTEXT_PRIVATE_KEY is correct
MARKET_RESOLVED	Market ended or resolved	Cannot trade this market
ADMIN_VOID	Order was voided administratively by the system	Inspect account and market state, then retry if appropriate

High Slippage in Simulation

1. Check orderbook depth — context_get_orderbook — is there sufficient liquidity at reasonable prices?
2. Reduce size — re-simulate with a smaller amount. Large orders eat through the book.
3. Use a limit order — instead of a market order, set a priceCents that caps your worst-case fill.
4. Slippage thresholds: <2% is good, 2–5% is acceptable for small markets, >5% means insufficient liquidity — reduce size or wait.

Gotchas

• Simulation and execution can differ. The orderbook changes between calls. Simulate is a preview, not a guarantee.
• voided ≠ cancelled. Voided means the system rejected it (bad params, no balance). Cancelled means you cancelled it intentionally.
• Orders on resolved markets are automatically voided. If a market resolves while your order is open, it gets voided — this is expected behavior.
• MAKER_ONLY constraint causes reverts. If you see InvalidRoleConstraint errors, someone set makerRoleConstraint: 1. Never use this value.

Verification

After resolving the issue, place a new order and confirm it appears in context_my_orders with status "open".

See Also

• Order Lifecycle — All states, void reasons, fill tracking
• Orders API — Method signatures and types