Execute multiple orders as a combo. Supports options spreads or option+perp combos. Only fill_or_kill (FOK) order type is supported.

Important Constraints:

• Price Increment (Perp Leg Only): If limit_perp_price is provided, it must be divisible by the minimum price increment for the base asset (see GET /api/v1/exchange_info → orderConstraints.priceIncrements). Option legs in combo orders are not subject to price increment validation since the net limit price is calculated across multiple legs.
• Size Increment: Each leg's size is denominated in base contracts and must be divisible by the size increment (see GET /api/v1/exchange_info → orderConstraints.options.sizeIncrements or orderConstraints.perpetuals.sizeIncrements)
• Leg limits: A combo may contain at most 6 option legs and at most 1 perpetual leg (maximum 7 legs total). Exceeding these returns HTTP 400 with must contain no more than 6 option legs or must contain no more than 1 perp leg
• limit_perp_price: Required (and must be positive) when the combo includes a perpetual leg, and must be omitted when it does not. Violations return HTTP 400 with must include a positive limit_perp_price when a perp leg is present or must not include limit_perp_price when no perp leg is present
• Minimum Size: Each leg must meet the per-asset minimum size. Perpetual minimum size equals the size increment, in base contracts: BTC 0.0001, ETH 0.001, ARB 1

Authentication Options:

• Signature: Include signature and signature_deadline fields in the request
• One-click session: Include x-one-click header with session hash (no signature needed)

When using one-click sessions, the signature fields can be omitted from the request.