To help you get started, we've collected the most common ways that @kentico/kontent-delivery is being used within popular public projects.

JavaScript Delivery SDK Documentation

JavaScript Delivery SDK is a client library for retrieving data from Kontent by Kentico. Works both in browser & node.js environments.

Kontent Delivery SDK

Installation

You can install this library using npm or you can use global CDNs such jsdelivr.

npm

npm i @kentico/kontent-delivery --save

UMD Bundles

When using UMD bundle and including this library in script tag on your html page, you can find it under the kontentDelivery global variable.

Bundles are distributed in dist/_bundles folder:

• dist/_bundles/kontent-delivery.umd.js
• dist/_bundles/kontent-delivery.umd.min.js

CDN

kontent-delivery.umd.js

https://cdn.jsdelivr.net/npm/@kentico/kontent-delivery@11.0.0/dist/bundles/kontent-delivery.umd.js

kontent-delivery.umd.min.js

https://cdn.jsdelivr.net/npm/@kentico/kontent-delivery@11.0.0/dist/bundles/kontent-delivery.umd.min.js

TypeScript & ES6

import { IContentItem, Elements, createDeliveryClient } from '@kentico/kontent-delivery';

/**
 * Defining models is optional, but will greatly benefit development
 * experience & further maintenance of your code
 */
export type Movie = IContentItem<{
    title: Elements.TextElement;
    plot: Elements.RichTextElement;
    released: Elements.DateTimeElement;
    length: Elements.NumberElement;
    poster: Elements.AssetsElement;
    category: Elements.MultipleChoiceElement;
    stars: Elements.LinkedItemsElement;
    seoname: Elements.UrlSlugElement;
    releaseCategory: Elements.TaxonomyElement;
}>;

// initialize delivery client
const deliveryClient = createDeliveryClient({
    projectId: ''
});

// fetch items
const response = await deliveryClient.items().type('').toPromise();

// read data of first item
const movieText = response.data.items[0].title.value;

JavaScript & CommonJS

const KontentDelivery = require('@kentico/kontent-delivery');

// initialize delivery client
const deliveryClient = KontentDelivery.createDeliveryClient({
  projectId: '',
});

// fetch items
const response = await deliveryClient.items()
  .type('')
  .toPromise();

// read data of first item
const movieText = response.data.items[0].title.value;

HTML & UMD & CDN

    
        <title>Kontent SDK - Html sample</title>
        
    
    
        
        <h1>See console</h1>
    

SDK Documentation

Client configuration

Following is a list of configuration options for DeliveryClient (IDeliveryClientConfig):

Property	type	description
projectId	string	ProjectId of your Kontent project
elementResolver?	ElementResolver	Element resolver used to map custom elements
previewApiKey?	string	Preview API key used to get unpublished content items
defaultLanguage?	string	Sets default language that will be used for all queries unless overriden with query parameters
proxy?	IDeliveryClientProxyConfig	Can be used to configure custom URLs. Useful when you use reverse proxy or have a need to transform URL - e.g. to remove 'projectId'
secureApiKey?	string	Secured API key: Use secured API only when running on Node.JS server, otherwise you can expose your key
defaultQueryConfig?	IQueryConfig	Default configuration for all queries. Can be overriden by indidividual queries
httpService ?	IHttpService	Can be used to inject custom http service for performing requests
globalHeaders?	(queryConfig: IQueryConfig) => IHeader[]	Adds ability to add extra headers to each http request
retryStrategy?	IRetryStrategyOptions	Retry strategy configuration
linkedItemsReferenceHandler?	LinkedItemsReferenceHandler	Indicates if content items are automatically mapped. Available values: 'map' or 'ignore'
propertyNameResolver?	PropertyNameResolver	Used to map properties. Choose one of following default resolvers: snakeCasePropertyNameResolver, pascalCasePropertyNameResolver & camelCasePropertyNameResolver or create your own PropertyNameResolver function
assetsDomain?	string	Custom domain for assets. Changes url of assets in both asset & rich text elements
defaultRenditionPreset?	string	Codename of rendition preset to be applied by default to the base asset URL path when present. When set, the SDK will provide the URL of customized images by default. Right now the only supported preset codename is default.

Create typed models

> Recommended:Use the Kontent Model Generator to automatically > generate TypeScript models based on the content types in your Kontent project.

You may define optional models in Typescript representing your actual data defined in Kontent projects. You can also auto-generate these models (see below).

import { IContentItem, Elements } from '@kentico/kontent-delivery';

export type Movie = IContentItem<{
    title: Elements.TextElement;
    plot: Elements.RichTextElement;
    released: Elements.DateTimeElement;
    length: Elements.NumberElement;
    poster: Elements.AssetsElement;
    category: Elements.MultipleChoiceElement;
    stars: Elements.LinkedItemsElement;
    seoname: Elements.UrlSlugElement;
    releaseCategory: Elements.TaxonomyElement;
}>;

Fetch data

To get multiple content items, use the items method. You can specify the content type with the type method:

deliveryClient.items().type('typeCodename').toPromise();

deliveryClient.item('itemCodename').toPromise();

Supported elements: TextElement, MultipleChoiceElement, DateTimeElement, RichTextElement, NumberElement, AssetsElement, UrlSlugElement, TaxonomyElement, LinkedItemsElement and CustomElement. Additionally you might also get UknownElement or custom model if you register it for your custom elements.

Use custom models for Custom elements

You can register an ElementResolver to map custom elements into dedicated element models and work with data more effectively.

For example, if you have a custom color element in your Kontent project with json data like:

 "color": {
  "type": "custom",
  "name": "Color",
  "value": "{\"red\":167,\"green\":96,\"blue\":197}"
  }

You can create a ColorElement type with strongly typed properties for red, green & blue values that you will parse from the json.

import { ElementModels, Elements, createDeliveryClient } from '@kentico/kontent-delivery';

type ColorElement = Elements.CustomElement<{
    red: number;
    green: number;
    blue: number;
}>;

To resolve your custom element into ColorElement, use the ElementResolver in your dleivery client config:

const client = createDeliveryClient({
    projectId: '',
    elementResolver: (elementWrapper) => {
        if (elementWrapper.rawElement.type === 'color') {
            const parsed = JSON.parse(elementWrapper.rawElement.value);

            return {
                red: parsed.red,
                green: parsed.green,
                blue: parsed.blue
            };
        }

        return undefined;
    }
});

You can then use this custom element type in your models:

type Movie = IContentItem<{
    color: ColorElement;
    title: Elements.TextElement;
}>;

Query parameters

The SDK supports the following query parameters: depthParameter, elementsParameter, limitParameter, orderParameter, skipParameter and languageParameter. For more information about the parameters, see the SDK query methods below. You can also head over to Delivery API reference.

// Gets 5 items based on the Movie type
deliveryClient.items().type('movie').limitParameter(5).skipParameter(2).toPromise();

Filter content

This example returns all Movie content items whose title element is equal to Warrior. Filters are also considered query parameters and can be combined. See Content filtering in API reference for more general examples.

Supported filters: type, types, allFilter, anyFilter, containsFilter, equalsFilter, greaterThanFilter, greaterThanOrEqualFilter, infilter, lessThanFilter, lessThanOrEqualFilter, rangeFilter, emptyFilter, notEmptyFilter, notEqualsFilter, NotInFilter.

// Gets items based on the Movie type with 'Warrior' in their 'Title' element
deliveryClient.items().type('movie').equalsFilter('elements.title', 'Warrior').toPromise();

Filtering methods

Filter	Description
type	Retrieve only content items based on the given type.
types	Retrieve only content items based on the given types.
allFilte	Element with an array of values contains the specified list of values.
anyFilter	Element with an array of values contains any value from the specified list of values.
containsFilter	Element with an array of values contains the specified value.
equalsFilter	Element value is the same as the specified value
greaterThanFilter	Element value is greater than the specified value.
greaterThanOrEqualFilter	Element value is greater than or equals the specified value.
infilter	Element value is in the specified list of values.
lessThanFilter	Element value is less than the specified value.
lessThanOrEqualFilter	Element value is less than or equals the specified value
rangeFilter	Element value falls in the specified range of two values, both inclusive.
emptyFilter	Property value is empty.
NotEmptyFilter	Property value is not empty.
notEqualsFilter	Property value does not equal the specified value.
notInFilter	Property value is not in the specified list of values.

Sort content

You can sort data by using any of following methods:

deliveryClient.items().type('movie').orderByDescending('elements.title').toPromise();

deliveryClient.items().type('movie').orderByAscending('elements.title').toPromise();

deliveryClient.items().type('movie').orderParameter('elements.title', 'desc').toPromise();

Execute queries with custom URL

When you have an URL (i.e. for next page in paging, for testing purposes or just if you prefer to build it on your own) and still want to leverage SDK functionality such as type mapping, property resolving etc., use withUrl parameter on any query such as:

deliveryClient
    .items()
    .withUrl('https://deliver.kontent.ai/da5abe9f-fdad-4168-97cd-b3464be2ccb9/items?system.type=movie')
    .toPromise();

Custom parameters

In case you need to use custom parameters to build up an URL, use withParameter method:

deliveryClient.items().withParameter('name', 'value').toPromise();

Get localized items

You can specify language of items with languageParameter of a particular query. You can also define default language that will be used if languageParameter is not used during the initialization of delivery client.

import { createDeliveryClient } from '@kentico/kontent-delivery';

var deliveryClient = new createDeliveryClient({
    projectId: '',
    defaultLanguage: 'es'
});

// Gets items in 'es' language because it is marked as default
deliveryClient.item('warrior').toPromise();

// Gets items in 'en' language because language parameter has priority over the default one
deliveryClient.item('warrior').languageParameter(`en`).toPromise();

Property name resolvers

Kontent element codenames are always in lowercase and use underscore as a replacement for special characters. Using underscores might not be what you want to use in your code. Maybe you want to use camelCase, which is exactly what you can do by registering a propertyNameResolver. The following example converts first_name element name to firstName.

import { ContentItem, Elements, createDeliveryClient  } from '@kentico/kontent-delivery';

type Actor = IContentItem<{
    firstName: Elements.TextElement;
}>;

const deliveryClient = createDeliveryClient({
  projectId: '';
  propertyNameResolver: (contentType, element) => {
    if (element === 'first_name') {
        return 'firstName';
    }
    return element;
    }
});

Rather then registering all elements manually, you can also use one of the built-in property name resolvers: snakeCasePropertyNameResolver, pascalCasePropertyNameResolver & camelCasePropertyNameResolver

import { createDeliveryClient, snakeCasePropertyNameResolver, pascalCasePropertyNameResolver, camelCasePropertyNameResolver  } from '@kentico/kontent-delivery';

const deliveryClient = createDeliveryClient({
  projectId: '';
  propertyNameResolver: camelCasePropertyNameResolver,
  // propertyNameResolver: snakeCasePropertyNameResolver,
  // propertyNameResolver: pascalCasePropertyNameResolver,
});

Preview mode

You can enable the preview mode either globally (when initializing the DeliveryClient) or per query. In each case, you need to set previewApiKey in the delivery client global configuration.

Enable preview mode globally

import { createDeliveryClient } from '@kentico/kontent-delivery';

const deliveryClient = createDeliveryClient({
  projectId: '';
  previewApiKey: '',
  defaultQueryConfig: {
    usePreviewMode: true
  }
});

Enable preview mode per query

deliveryClient
    .items()
    .queryConfig({
        usePreviewMode: true
    })
    .toPromise();

Secure Delivery API

Using the Delivery API with secure access enabled is recommend only when the request is not being executed on the client (browser) because otherwise you will expose the API key publicly.

import { createDeliveryClient } from '@kentico/kontent-delivery';

const deliveryClient = createDeliveryClient({
  projectId: '';
  secureApiKey: '',
    defaultQueryConfig: {
      // Enabled secure access for all queries
      useSecuredMode: true
  }
});

As with preview mode, you can also override global settings on query level.

deliveryClient
    .items()
    .queryConfig({
        // Enables secure access only for this query
        useSecuredMode: true
    })
    .toPromise();

Image transformation

Use ImageUrlBuilder for your image transformations on asset URLs.

import { transformImageUrl } from '@kentico/kontent-delivery';

// Sample asset URL; You'll find URLs like these in asset and rich text elements
const assetUrl = `https://assets.kenticocloud.com:443/da5abe9f-fdad-4168-97cd-b3464be2ccb9/22504ba8-2075-48fa-9d4f-8fce3de1754a/warrior.jpg`;

const transformedUrl = transformImageUrl(assetUrl)
    .withDpr(2)
    .withCompression('lossless')
    .withQuality(4)
    .withHeight(200)
    .withWidth(100)
    .getUrl();

Paging

All listing queries support automatic paging. To use automatic paging, use toAllPromise extension method:

// this executed multiple HTTP requests until it gets all items
const response = await deliveryClient.items().limitParameter(5).toAllPromise();

Alternatively, you may also specify maximum number of pages you want to get:

// only gets 3 page at maximum
const response = await deliveryClient.items().limitParameter(5).toAllPromise({
    pages: 3
});

Resolving rich text elements

Rich text elements in Kontent by Kentico may contain linked items and components. For example, if you write a blog post, you might want to insert a video or testimonial to a specific place in your article.

You need to define how these objects resolve to the HTML that will be rendered. This SDK provides you with few resolvers that help you to transform the input HTML to your desired HTML, JSON or object.

Built-in resolvers provided by SDK:

Resolver	Description	Usage
RichTextHtmlResolver	Tranforms rich text HTML by replacing linked items, links or images with custom HTML	createRichTextHtmlResolver().resolveRichText(data)
RichTextJsonResolver	Tranforms rich text HTML into JSON	createRichTextJsonResolver().resolveRichText(data)
RichTextObjectResolver	Tranforms rich text HTML into javascript Object	createRichTextObjectResolver().resolveRichText(data)
AsyncRichTextHtmlResolver	Async version of RichTextHtmlResolver	await createAsyncRichTextHtmlResolver().resolveRichTextAsync(data)

Example use of RichTextHtmlResolver

import { createRichTextHtmlResolver, createDeliveryClient, linkedItemsHelper } from '@kentico/kontent-delivery';

export type Movie = IContentItem<{
    plot: Elements.RichTextElement;
}>;

export type Actor = IContentItem<{
    firstName: Elements.RichTextElement;
}>;

// get content item with rich text element
const response = (await createDeliveryClient({ projectId: '' }).item('itemCodename').toPromise()).data;

// get rich text element
const richTextElement = response.item.plot;

// resolve HTML
const resolvedRichText = createRichTextHtmlResolver().resolveRichText({
    element: richTextElement,
    linkedItems: linkedItemsHelper.convertLinkedItemsToArray(response.linkedItems),
    imageResolver: (imageId, image) => {
        return {
            imageHtml: `<img src="${image?.url}" class="xImage">`,
            // alternatively you may return just url
            imageUrl: 'customUrl'
        };
    },
    urlResolver: (linkId, linkText, link) =&gt; {
        return {
            linkHtml: `<a class="xLink">${link?.link?.urlSlug}</a>`,
            // alternatively you may return just url
            linkUrl: 'customUrl'
        };
    },
    contentItemResolver: (itemId, contentItem) =&gt; {
        if (contentItem &amp;&amp; contentItem.system.type === 'actor') {
            const actor = contentItem as Actor;
            return {
                contentItemHtml: `<div class="xClass">${actor.elements.firstName.value}</div>`
            };
        }

        return {
            contentItemHtml: ''
        };
    }
});

const resolvedHtml = resolvedRichText.html;

Example use of RichTextJsonResolver

import { createRichTextHtmlResolver, createDeliveryClient, linkedItemsHelper } from '@kentico/kontent-delivery';

// get content item with rich text element
const response = (await createDeliveryClient({ projectId: '' }).item('itemCodename').toPromise()).data;

// get rich text element
const richTextElement = response.item.plot;

// transform rich text html into json
const json = createRichTextJsonResolver().resolveRichText({
    element: response.item.elements.plot,
    linkedItems: linkedItemsHelper.convertLinkedItemsToArray(response.linkedItems),
});

Resolving rich text in node.js

If you need to resolve rich text in node.js, you have to install following parser:

npm i @kentico/kontent-delivery-node-parser --save

Once installed, it can be used by passing the parser to rich text resolver:

import { createRichTextHtmlResolver, createAsyncRichTextHtmlResolver } from '@kentico/kontent-delivery';
import { nodeParser, asyncNodeParser } from '@kentico/kontent-delivery-node-parser';

// transform rich text html into json
const json = createRichTextHtmlResolver(nodeParser).resolveRichText(data);

// or
const html = await createAsyncRichTextHtmlResolver(asyncNodeParser).resolveRichText(data);

Creating custom rich text resolvers

This SDK provides you with browserParser which you can use to implement your own rich text resolver. A common usecase for creating custom resolvers is when you want to convert rich text element into, for example, react components, angular commponents or components in some other popular framework. The parser will take care of actually parsing html, while you can focus on creating specific logic for creating components dynamically.

Get content types

To retrieve information about your content types, you can use the type and types methods.

deliveryClient
    .type('movie') // codename of the type
    .toPromise();

deliveryClient.types().toPromise();

deliveryClient.types().toAllPromise();

Get taxonomies

To retrieve information about your taxonomies, you can use the taxonomy and taxonomies methods.

deliveryClient
    .taxonomy('taxonomyGroupName') // codename of the Taxonomy group
    .toPromise();

deliveryClient.taxonomies().toPromise();

deliveryClient.taxonomies().toAllPromise();

Proxy configuration

If you want to use a proxy server, you need to use different domain or otherwise transform URL. By using proxy configuration option you can define your own base domains as well as URL format. This is useful if you need to for example hide the projectId from URL.

IDeliveryClientProxyConfig offers 3 ways of configuring proxy url:

1. baseUrl - Base url used for preview reqeusts. Defaults to 'preview-deliver.kontent.ai'
2. basePreviewUrl - Base url used for all requests. Defaults to 'deliver.kontent.ai'
3. advancedProxyUrlResolver - Resolver function where you get IProxyUrlData context data (includes domain, action, query parameters..) and can fully customize final URL.

Examples:

const client = createDeliveryClient({
    projectId: '',
    // Will be used instead of 'https://deliver.kontent.ai' for all requests.
    // Parameters, filters, project Id and other parts of URL will use default values.
    proxy: {
        baseUrl: 'https://my-proxy.io'
    }
});

const client = createDeliveryClient({
    projectId: '',
    proxy: {
        advancedProxyUrlResolver: (data) => {
            const action = data.action; // /items
            const domain = data.domain; // https://deliver.kontent.ai
            const projectId = data.projectId; // xxx
            const queryString = data.queryString; // e.g. ?depth=1&elements=xElement
            const queryParameters = data.queryParameters; // array with query parameters parameters
            const queryConfig = data.queryConfig; // query configuration
            return `https://my-proxy.io${action}${queryString}`; // proxy url with omitted project Id
        }
    }
});

Error handling

If the error originates in Kontent by Kentico (see error responses), you will get a DeliveryError object instance with more specific information. Otherwise, you will get original error.

import { DeliveryError } from '@kentico/kontent-delivery';

try {
    await deliveryClient.item('invalid_codename').toPromise();
} catch (error) {
    if (error instanceof DeliveryError) {
        // delivery specific error (e.g. item with codename not found...)
        console.log(err.message, err.errorCode);
    } else {
        // some other error
        console.log(error);
    }
}

Remapping json responses

In some scenarios you might want to store json response for later use and use SDK to map the response for you. There are 2 ways you can map previously stored json:

const result = await deliveryClient.item('codename').toPromise();

const json = result.response.data;

// approach #1
const remappedData = deliveryClient.mappingService.viewContentItemResponse(json);

// approach #2
const remappedData = deliveryClient.item(movieCodename).map(json);

Handling circular references

By default the SDK automatically maps content items present in linked items & rich text elements. Linked items can reference other linked items in their tree (e.g. child item referencing parent) which may cause infinite nesting (circular reference). This behavior is not an issue for most scenarios, in fact it is beneficial as you can easily access all linked items. However, you cannot easily serialize such model. Using e.g. JSON.stringify would fail if there are circular references.

For this reason, you may disable mapping of linked items with linkedItemsReferenceHandler configuration option.

 const client = getTestDeliveryClient({
    projectId: '',
    linkedItemsReferenceHandler: 'ignore' // or 'map'
});

Using custom HTTP service

The SDK allows you to inject your own instance of a class implementing the IHttpService interface. This way you can easily mock responses, implement your own http service, or modify the requests in some other way.

Sample of a test HttpService implementation can be found at https://github.com/Kentico/kontent-core-js/blob/7ec7faaa779a4aa55802ade927f296cc3619a720/lib/http/test-http.service.ts

Once you have your HttpService, use it in delivery client initialization:

const deliveryClient = createDeliveryClient({
    projectId: '',
    httpService: YourHttpServiceImplementation
});

Debugging

Accessing request data

Every response from this SDK contains additional debug data you can use to inspect when something is not right or if you need to access response headers or other network related properties.

const deliveryResponse = await createDeliveryClient({ projectId: ' If you want to mock http responses, it is possible to use
> [custom Http Service](https://github.com/Kentico/kontent-core-js#testing) as a part of the
> [delivery client configuration](#client-configuration).

## Feedback & Contribution

Feedback & Contributions are welcomed. Feel free to take/start an issue & submit PR.