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REST API: Population & Field Selection

The REST API by default does not populate any relations, media fields, components, or dynamic zones. Use the populate parameter to populate specific fields and the select parameter to return only specific fields with the query results.

💡 Tip

Strapi takes advantage of the ability of the qs library to parse nested objects to create more complex queries.

Use qs directly to generate complex queries instead of creating them manually. Examples in this documentation showcase how you can use qs.

You can also use the interactive query builder if you prefer playing with our online tool instead of generating queries with qs on your machine.

🏗 Work-in-progress

Strapi v4 docs very recently included a more extensive description of how to use the populate parameter, including an extensive API reference and additional guides. These v4 pages are currently being ported and adapted to Strapi 5 docs so that examples reflect the new data response format.

In the meantime, you can trust the content of the present page as accurate as it already reflects the new Strapi 5, flattened response format (see breaking change entry and REST API introduction for details); the present page is just not as complete as its v4 equivalent yet.

Field selection

Queries can accept a fields parameter to select only some fields. By default, only the following types of fields are returned:

  • string types: string, text, richtext, enumeration, email, password, and uid,
  • date types: date, time, datetime, and timestamp,
  • number types: integer, biginteger, float, and decimal,
  • generic types: boolean, array, and JSON.
Use caseExample parameter syntax
Select a single fieldfields=name
Select multiple fieldsfields[0]=name&fields[1]=description
✏️ Note

Field selection does not work on relational, media, component, or dynamic zone fields. To populate these fields, use the populate parameter.

Example request: Return only name and description fields

GET /api/restaurants?fields[0]=name&fields[1]=description

JavaScript query (built with the qs library):

The query URL above was built using the qs library. qs can be run locally on your machine, as shown in the following code example, or you can use our interactive query builder online tool.

const qs = require('qs');
const query = qs.stringify(
{
fields: ['name', 'description'],
},
{
encodeValuesOnly: true, // prettify URL
}
);

await request(`/api/users?${query}`);
Example response
{
"data": [
{
"id": 4,
"Name": "Pizzeria Arrivederci",
"Description": [
{
"type": "paragraph",
"children": [
{
"type": "text",
"text": "Specialized in pizza, we invite you to rediscover our classics, such as 4 Formaggi or Calzone, and our original creations such as Do Luigi or Nduja."
}
]
}
],
"documentId": "lr5wju2og49bf820kj9kz8c3"
},
// …
],
"meta": {
"pagination": {
"page": 1,
"pageSize": 25,
"pageCount": 1,
"total": 4
}
}
}

Population

The REST API by default does not populate any type of fields, so it will not populate relations, media fields, components, or dynamic zones unless you pass a populate parameter to populate various field types.

The populate parameter can be used alone or in combination with with multiple operators to have much more control over the population.

Caution

The find permission must be enabled for the content-types that are being populated. If a role doesn't have access to a content-type it will not be populated (see User Guide for additional information on how to enable find permissions for content-types).

✏️ Note

It's currently not possible to return just an array of ids with a request.

🤓 Populating guides

The REST API guides section includes more detailed information about various possible use cases for the populate parameter:

  • The Understanding populate guide explains in details how populate works, with diagrams, comparisons, and real-world examples.
  • The How to populate creator fields guide provides step-by-step instructions on how to add createdBy and updatedBy fields to your queries responses.

The following table sums up possible populate use cases and their associated parameter syntaxes, and links to sections of the Understanding populate guide which includes more detailed explanations:

Use caseExample parameter syntaxDetailed explanations to read
Populate everything, 1 level deep, including media fields, relations, components, and dynamic zonespopulate=*Populate all relations and fields, 1 level deep
Populate one relation,
1 level deep
populate=a-relation-namePopulate 1 level deep for specific relations
Populate several relations,
1 level deep
populate[0]=relation-name&populate[1]=another-relation-name&populate[2]=yet-another-relation-namePopulate 1 level deep for specific relations
Populate some relations, several levels deeppopulate[root-relation-name][populate][0]=nested-relation-namePopulate several levels deep for specific relations
Populate a componentpopulate[0]=component-namePopulate components
Populate a component and one of its nested componentspopulate[0]=component-name&populate[1]=component-name.nested-component-namePopulate components
Populate a dynamic zone (only its first-level elements)populate[0]=dynamic-zone-namePopulate dynamic zones
Populate a dynamic zone and its nested elements and relations, using a precisely defined, detailed population strategypopulate[dynamic-zone-name][on][component-category.component-name][populate][relation-name][populate][0]=field-namePopulate dynamic zones
💡 Tip

The easiest way to build complex queries with multiple-level population is to use our interactive query builder tool.

Combining Population with other operators

By utilizing the populate operator it is possible to combine other operators such as field selection, filters, and sort in the population queries.

Caution

The population and pagination operators cannot be combined.

Populate with field selection

fields and populate can be combined.

Example request

GET /api/articles?fields[0]=title&fields[1]=slug&populate[headerImage][fields][0]=name&populate[headerImage][fields][1]=url

JavaScript query (built with the qs library):

The query URL above was built using the qs library. qs can be run locally on your machine, as shown in the following code example, or you can use our interactive query builder online tool.

const qs = require('qs');
const query = qs.stringify(
{
fields: ['title', 'slug'],
populate: {
headerImage: {
fields: ['name', 'url'],
},
},
},
{
encodeValuesOnly: true, // prettify URL
}
);

await request(`/api/articles?${query}`);
Example response
{
"data": [
{
"id": 1,
"documentId": "h90lgohlzfpjf3bvan72mzll",
"title": "Test Article",
"slug": "test-article",
"headerImage": {
"id": 1,
"documentId": "cf07g1dbusqr8mzmlbqvlegx",
"name": "17520.jpg",
"url": "/uploads/17520_73c601c014.jpg"
}
}
],
"meta": {
// ...
}
}

Populate with filtering

filters and populate can be combined.

Example request

GET /api/articles?populate[categories][sort][0]=name%3Aasc&populate[categories][filters][name][$eq]=Cars

JavaScript query (built with the qs library):

The query URL above was built using the qs library. qs can be run locally on your machine, as shown in the following code example, or you can use our interactive query builder online tool.

const qs = require('qs');
const query = qs.stringify(
{
populate: {
categories: {
sort: ['name:asc'],
filters: {
name: {
$eq: 'Cars',
},
},
},
},
},
{
encodeValuesOnly: true, // prettify URL
}
);

await request(`/api/articles?${query}`);
Example response
{
"data": [
{
"id": 1,
"documentId": "a1b2c3d4e5d6f7g8h9i0jkl",
"title": "Test Article",
// ...
"categories": {
"data": [
{
"id": 2,
"documentId": "jKd8djla9ndalk98hflj3",
"name": "Cars"
// ...
}
]
}
}
}
],
"meta": {
// ...
}
}