Interface OrderConstraints

Set true only for a venue that genuinely trades fractions, such as crypto. Absent means whole quantities, which is every Indian equity and F&O contract and the reason fractional quantities are rejected by default: a fractional quantity reaching those brokers is a defect, not a preference. A lotSize grid still applies when this is true.

Max quantity per single order (exchange freeze limit).

Contract lot size. When set, quantity must be a whole multiple of it: 100 on a 75-lot future is rejected here rather than by the exchange.

Price-dependent ticks. When set it decides every snap and tickSize is only read by older code, so give it the schedule's minMove. Absent or null, the constant tickSize snaps exactly as it always has.