Field types

Every field type, with its options, defaults and the values it accepts. For a guided introduction, see Fields.

A field is a JSON object in a schema’s fields list, such as {"name": "title", "type": "text", "required": true}. A key the server doesn’t know is refused by name (field `title`: unknown option `maxLenght` ), and so is an unknown type.

Options on every field

Option	Type	Default	Description
name	string	none	Required on every field except row, collapsible and tabs. 1 to 64 letters, digits and underscores, starting with a letter. id, createdAt, updatedAt and status are reserved at the top level, and in users so are email, role, password and currentPassword.
type	string	none	Required. One of the types on this page.
label	string	none	A human name. Titles a collapsible.
required	boolean	false	The field must have a value.
default	any	none	Used when a new document doesn’t send the field. Must itself be a valid value.
unique	boolean	false	No two live documents may share a value. Top-level fields only, and only the types in Unique and filterable.
filterable	boolean	false	Builds a database index so filters and sorts on the field stay fast. Same limits as unique.
admin	object	{}	Hints for an editing screen. See Admin hints.
virtual	string	none	A path through a relationship, such as author.name. The value is read from there, never stored. See Joins and virtual fields.
access	object	none	Field rules: read, create and update. See Field rules.

Text and numbers

text

One line of text, or a list of them with hasMany. Stored as a string, or an array of strings.

Option	Type	Default	Description
minLength	integer	none	Fewest characters. Counts characters, not bytes.
maxLength	integer	none	Most characters.
hasMany	boolean	false	Store a list of strings.
minRows	integer	none	Fewest items. Only with hasMany.
maxRows	integer	none	Most items. Only with hasMany.

textarea

Longer text. Stored as a string.

Option	Type	Default	Description
minLength	integer	none	Fewest characters.
maxLength	integer	none	Most characters.

number

A number, or a list of them with hasMany. Stored as a JSON number.

Option	Type	Default	Description
min	number	none	Smallest value allowed.
max	number	none	Largest value allowed.
integer	boolean	false	Whole numbers only.
hasMany	boolean	false	Store a list of numbers.
minRows	integer	none	Fewest items. Only with hasMany.
maxRows	integer	none	Most items. Only with hasMany.

code

Source code, stored as a string.

Option	Type	Default	Description
language	string	none	The language for an editor’s highlighting, such as rust or html. Not checked.

json

Any JSON value. No options of its own. null inside the value is ordinary data; null as the whole value clears the field. A json field can’t be filtered, sorted, unique or filterable.

Choices and flags

boolean

true or false. No options of its own. checkbox is accepted as another name for it, and saved schemas show boolean.

select

One of a fixed list of values, or several with multiple. Stored as a string, or an array of strings.

Option	Type	Default	Description
options	array	none	Required, at least one. Each is a value ("draft") or {"label": "Draft", "value": "draft"}. Values must be unique. Only the value is stored.
multiple	boolean	false	Store a list of values.

radio

One of a fixed list of values. Stored as a string.

Option	Type	Default	Description
options	array	none	Required, at least one, as for select.

Dates, addresses and places

date

A date-time, or a plain date with dateOnly. A date-time is sent in RFC 3339 form with any offset and stored in UTC to the millisecond: 2026-10-12T09:30:00+02:00 is stored as 2026-10-12T07:30:00.000Z. Years run from 0 to 9999.

Option	Type	Default	Description
dateOnly	boolean	false	Store a date like 2026-10-12, with no time.

email

An email address, stored as a string. No options of its own.

url

An http or https URL with a host, stored as a string. No options of its own.

point

A location as [longitude, latitude], such as [-0.1276, 51.5072]. Longitude runs from -180 to 180 and latitude from -90 to 90. No options of its own. Filter it by distance with near; it can’t be sorted, unique or filterable.

slug

A URL-friendly name: lowercase letters, digits and single hyphens, like my-first-post, up to 200 bytes. A slug is always unique and must be a top-level field.

Option	Type	Default	Description
from	string	none	A top-level text field (without hasMany) to make the slug from when a document arrives without one: Shipping v0.1.0 becomes shipping-v0-1-0.

Links

relationship

A link to a document, or a list of links with hasMany. With one collection in relationTo, a link is the document’s ID. With several, it’s {"relationTo": "<collection>", "value": "<document ID>"}. The linked document must exist and be readable by whoever saves the link. See Relationships.

Option	Type	Default	Description
relationTo	string or array	none	Required. The collection slug, or several. Each must be an existing collection (not a global) or this collection.
hasMany	boolean	false	Store a list of links.
maxDepth	integer, 0 to 5	none	Populate through this field at most this deep, whatever depth asks for.

join

The documents of another collection whose relationship links here, read fresh on every request and never stored. Returned as {"docs": […], "hasNextPage": …}. A join can’t be required, unique, filterable or virtual, have a default, sit inside an array, or belong to a global. See Join fields.

Option	Type	Default	Description
collection	string	none	Required. The collection to read from.
on	string	none	Required. The path of the relationship in collection that links here, such as category or links.target.
where	object	none	A filter always applied, such as {"published": {"equals": "true"}}. Uses the filter operators except near.
defaultLimit	integer, 1 to 100	10	Documents per join, unless the request asks otherwise.
defaultSort	string	newest first	A field of collection to sort by, with - for descending.

Structure

group

An object of other fields. Stored as a JSON object. Fields inside a group can’t be unique, filterable or a slug.

Option	Type	Default	Description
fields	array	none	Required. The fields inside.

array

A list of rows, each an object of other fields. Stored as an array of objects.

Option	Type	Default	Description
fields	array	none	Required. The fields of each row.
minRows	integer	none	Fewest rows.
maxRows	integer	none	Most rows.

Layout

Layout fields arrange other fields on an editing screen. Their fields are stored as if they sat directly in the parent, so layout changes no data. They take no name, can’t be required, unique or filterable, have no default, and can’t carry access rules. A collapsible needs a label; row and tabs take none.

row

Shows its fields side by side.

Option	Type	Default	Description
fields	array	none	Required. The fields to show.

collapsible

Shows its fields in a section that can fold away, titled by its label.

Option	Type	Default	Description
initiallyCollapsed	boolean	false	Start folded.
fields	array	none	Required. The fields to show.

tabs

Shows fields in tabs.

Option	Type	Default	Description
tabs	array	none	Required, at least one. Each tab is {"label": "…", "fields": […]}, plus an optional name. Every tab needs a label. A named tab nests its fields under that name, like a group.

Unique and filterable

unique, filterable and slug need a single comparable value at the top level of the schema. They work on:

• text and number without hasMany;
• textarea, boolean, date, email, url, radio, code and slug;
• select without multiple;
• relationship with one collection in relationTo and no hasMany.

Elsewhere they’re refused, such as field `tags`: select fields with multiple values can't be unique or filterable.

Admin hints

admin holds hints for an editing screen. The API stores them and returns them with the schema, but doesn’t enforce them.

Hint	Type	Default	Description
description	string	none	Help text.
placeholder	string	none	Placeholder text.
hidden	boolean	false	Hide the field.
readOnly	boolean	false	Show the field without letting people edit it.
position	main or sidebar	main	Where the field sits.
width	string	none	Such as 50% or 240px.
condition	object	none	Show the field only when another matches: {"field": "kind", "equals": "note"}. The test is one of equals, notEquals, in (an array) or exists (a boolean).

Validation messages

A document that doesn’t fit gets a 422 with one entry per problem (see Errors). These are the messages:

Message	Field types
is required	any, with required
unknown field	any: the body names a field the schema doesn’t have
expected text	text, textarea, code
must be at least N characters, must be at most N characters	text, textarea
expected a number, expected a whole number	number
must be at least N, must be at most N	number with min or max
expected true or false	boolean
expected a date like 2026-10-12	date with dateOnly
expected a date-time like 2026-10-12T09:30:00Z	date
expected an email address	email
expected an http or https URL	url
expected one of: a, b	select, radio
expected a list of: a, b	select with multiple
expected lowercase letters, digits and single hyphens, like my-first-post	slug
expected [longitude, latitude], like [-0.1276, 51.5072]	point
expected a document ID, expected a list of document IDs	relationship
expected a link like {"relationTo": "<collection>", "value": "<document ID>"} to one of: …	relationship with several collections
doesn't match any document in the related collection	relationship: no such document, or one you can’t read
expected a list	hasMany, multiple, array
must have at least N rows, must have at most N rows	hasMany with minRows/maxRows, array
expected an object	group, an array row
must not contain the NUL character	any text
is filled from posts.category; it can't be set	join
is read from author.name; set that instead	a virtual field
must be unique; another document already uses this value	unique, slug