Value types

A field’s type defines what its values mean: text, numbers, dates, choices, or structured data. Choose the type that matches your source data or the answer you need.

See what these fields look like →

Each type has its own settings. For example, text supports minLength; numbers support min.

The same nine types are used on both sides of the config, and nest inside each other.

The nine

Type	Holds	Own keys
text	A string	minLength, maxLength, pattern
integer	A whole number	min, max, step
number	A number, whole or fractional	min, max, step
boolean	true / false	—
date	A date	—
enum	One of a fixed set	choices
object	A record with named members	fields, table
array	A list	items
map	A dictionary	keys, values

Scalars

{ "name": "title",   "type": "text", "minLength": 1, "maxLength": 200 },
{ "name": "email",   "type": "text", "pattern": "^[^@\\s]+@[^@\\s]+$" },
{ "name": "rating",  "type": "integer", "min": 1, "max": 5, "step": 1 },
{ "name": "score",   "type": "number", "min": 0, "max": 1, "step": 0.01 },
{ "name": "flagged", "type": "boolean" },
{ "name": "created", "type": "date" },

pattern is a JavaScript regular expression. It is compiled when the config loads, so a malformed one is a config error rather than a surprise at render time.

step is not a constraint

step sizes the increment on a number box or slider. It is never used for validation — three clicks of a 0.1 slider legitimately produce 0.30000000000000004, and rejecting that would be absurd. If you need a real constraint, use min and max.

enum

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{
  "name": "sentiment",
  "type": "enum",
  "choices": [
    { "name": "positive", "display": "Positive", "shortcut": "p" },
    { "name": "neutral", "display": "Neutral" },
    { "name": "negative", "display": "Negative", "selectedStyle": { "tone": "danger" } },
  ],
}

A choice’s name is the literal string written to the file; display.title is only what the labeler sees. Choice names are trimmed and cannot be empty — an empty choice would read back as no value at all, making it both unselectable and impossible to round-trip.

See Shortcuts for shortcut, and Display for selectedStyle.

array

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// A list of strings — renders as chips.
{ "name": "tags", "type": "array", "items": { "type": "text" } },

// A multi-select — an array of enum is the only way to declare one.
{
  "name": "issues",
  "type": "array",
  "items": {
    "type": "enum",
    "choices": [{ "name": "toxic" }, { "name": "off-topic" }, { "name": "unhelpful" }],
  },
},

Use an array of enum for checkboxes that allow several answers. Selected values are written in declaration order, not click order, so the exported cell is stable however the labeler arrived at it.

object

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{
  "name": "checks",
  "type": "array",
  "items": {
    "type": "object",
    "fields": [
      { "name": "name",   "type": "text",    "display": "Check" },
      { "name": "passed", "type": "boolean", "display": "Passed" },
    ],
  },
},

An array of object renders as a table, one row per element. object.table controls how its members group into displayed columns — see TableView.

Names inside an object are JSON keys from your source payload, not column headers, so they are deliberately unconstrained: colons, slashes and unicode are all fine.

map

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{ "name": "tokenCounts", "type": "map", "values": { "type": "integer" } },

{
  "name": "annotators",
  "type": "map",
  "values": {
    "type": "object",
    "fields": [
      { "name": "role",       "type": "text" },
      { "name": "confidence", "type": "number" },
    ],
  },
},

keys defaults to text and is rarely worth stating. A map of object renders as a table keyed by its entries.

object

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and map are display-only

Objects and maps have no answer controls. To include them in output, use a matching copy field:

{ "name": "meta", "type": "object", "fields": [ /* … */ ] }
// ✗ "object" fields cannot be filled by a user; give the field a `fill`.

{ "name": "meta", "type": "object", "fields": [ /* … */ ], "fill": { "kind": "copy" } }
// ✓

How raw values become typed ones

How source cells are read covers empty values, conversion failures, and the accepted formats.

Dates

Use ISO dates such as 2026-10-09 to avoid month/day ambiguity. Date formats and UTC display →

Lists that are not JSON

Structured data uses JSON inside a cell. Scalar lists also accept several fallback formats. List parsing and CSV examples →

Full reference

Value types · Input fields · Output fields