Modifier display types

Set display_type on each pricing.modifiers entry for a modifier product. Fire spark validates that the value matches the group and modifier minimum and maximum quantities when you upsert a menu.

Menu sync overview

Read the menu sync guide for payload structure, modifier groups, and nested modifiers.

Where the field lives

display_type is not set on the modifier group. Groups use display_type for layout only (LIST or GRID). Per-modifier UI control lives on the modifier product under pricing.modifiers, one object per modifier_group_id where that product appears as an option:

{
  "id": "mod-ranch",
  "pricing": {
    "modifiers": [
      {
        "modifier_group_id": "mg-dipping-sauce",
        "minimum_quantity": 0,
        "maximum_quantity": 2,
        "display_type": "QUANTITY",
        "price": 0.5,
        "is_tax_inclusive": true,
        "tax_rate": 0.15
      }
    ]
  }
}

If you omit display_type, Fire spark infers the control from group and modifier quantity limits using the table below. Inference is deterministic when those bounds are present.

When the group max is greater than 1 and you omit maximum_quantity on the modifier entry, Fire spark treats the modifier as quantity-capable and infers QUANTITY. For checkbox-style options in a multi-select group, set maximum_quantity: 1. An explicit display_type is optional in that case — it documents intent for API consumers but must match the quantity bounds when you send it.

Expected display type by quantity limits

Use the group bounds from modifier_groups[].minimum_quantity and modifier_groups[].maximum_quantity, and the modifier bounds from the matching pricing.modifiers entry on the modifier product.

Group min	Group max	Modifier min	Modifier max	Expected `display_type`	Customer UI
`1`	`1`	any	`1` (or omitted)	`RADIO`	Pick exactly one option
`0`	`1`	any	`1` (or omitted)	`CHECKBOX`	Pick at most one optional option
any	`> 1`	any	`1`	`CHECKBOX`	Toggle each option on or off
any	`> 1`	any	omitted	`QUANTITY`	Stepper per option; omitted modifier max is treated as greater than 1
any	`> 1`	any	`> 1`	`QUANTITY`	Stepper per option

When the group max is greater than 1 and you omit maximum_quantity on the modifier entry, validation treats the modifier as quantity-capable (QUANTITY). Set maximum_quantity: 1 explicitly when the option should behave as a checkbox inside a multi-select group.

Examples

Scenario	Group min / max	Modifier max	`display_type`
Required drink on a combo	`1` / `1`	`1`	`RADIO`
Optional size upgrade	`0` / `1`	`1`	`CHECKBOX`
Up to three toppings	`0` / `3`	`1`	`CHECKBOX`
Up to two sauce cups of the same flavor	`0` / `2`	`2`	`QUANTITY`
Extra portions without a per-modifier cap	`0` / `5`	omitted	`QUANTITY`

Validation errors

Menu sync runs these checks on style: "DEFAULT" payloads.

Modifier group breaks the rule

Condition	What went wrong
`group.minimum_quantity > group.maximum_quantity`	The group bounds are invalid.
Group min `1`, max `1`, but a modifier has `maximum_quantity` other than `1`	Required single-select groups only allow one unit per option.
Group min `0`, max `1`, but a modifier has `maximum_quantity` other than `1`	Optional single-select groups only allow one unit per option.
Group max `> 1` and a modifier uses `display_type: "RADIO"`	`RADIO` is only valid when both group min and group max are `1`.

Modifier breaks the rule

Condition	What went wrong
`modifier.minimum_quantity > modifier.maximum_quantity`	The modifier bounds are invalid.
`modifier.maximum_quantity > group.maximum_quantity`	One option cannot exceed the group total cap.
`display_type` does not match the expected value from the table above	For example, `QUANTITY` with modifier max `1` in a multi-select group, or `RADIO` when group min is `0`.

Example rejection:

Modifier "mod-cheese" in group "mg-toppings" has display_type "RADIO" but must be "CHECKBOX": CHECKBOX because the group allows multiple selections (group min 0, max 3) and this modifier is capped at one unit (modifier min 0, max 1).

Decision flow

Field	Scope	Purpose
`modifier_groups[].minimum_quantity`	Group	Minimum total selections across all options in the group
`modifier_groups[].maximum_quantity`	Group	Maximum total selections across all options in the group
`pricing.modifiers[].minimum_quantity`	Modifier	Minimum units for this option
`pricing.modifiers[].maximum_quantity`	Modifier	Maximum units for this option
`pricing.modifiers[].display_type`	Modifier	UI control: `RADIO`, `CHECKBOX`, or `QUANTITY`

See Upsert menus for the full pricing.modifiers schema.

API Documentation

Endpoints

Guides

Resources

Modifier display types

Menu sync overview

Where the field lives

Expected display type by quantity limits

Examples

Validation errors

Modifier group breaks the rule

Modifier breaks the rule

Decision flow

Menu sync overview

​Where the field lives

​Expected display type by quantity limits

​Examples

​Validation errors

​Modifier group breaks the rule

​Modifier breaks the rule

​Decision flow

​Related fields

Where the field lives

Expected display type by quantity limits

Examples

Validation errors

Modifier group breaks the rule

Modifier breaks the rule

Decision flow

Related fields