@sanity/preview-kit

@sanity/preview-kit

[!IMPORTANT]
You're looking at the README for v5, the README for v4 is available here.

Sanity.io toolkit for building live-as-you-type content preview experiences and visual editing.

• Installation
• @sanity/preview-kit
  • Live real-time preview for React
    • 1. Create a client instance
    • 2. Define a <LiveQueryProvider /> component
    • 3. Making a Remix route conditionally preview drafts
    • 4. Adding the useLiveQuery hook to components that need to re-render in real-time
      • Implementing a Loading UI with useLiveQuery
      • Optimizing performance
    • Advanced usage
      • Using the LiveQuery wrapper component instead of the useLiveQuery hook
      • Trouble-shooting and debugging
      • Content Source Map features
• @sanity/preview-kit/client
  • Visual Editing with Content Source Maps
    • Enhanced Sanity client with createClient
      • studioUrl
      • encodeSourceMap
      • encodeSourceMapAtPath
      • logger
      • resultSourceMap
  • Using the Content Source Map with custom logic
  • Using Perspectives
• @sanity/preview-kit/csm
  • Transcoding
• Release new version
• License

Installation

npm i @sanity/preview-kit @sanity/client

pnpm i @sanity/preview-kit @sanity/client

yarn add @sanity/preview-kit @sanity/client

@sanity/preview-kit

Note

This is the new docs for @sanity/preview-kit v2. If you're looking for docs for v1 APIs, like definePreview and usePreview, they're available on the v1 branch..

There's a full migration guide available here.

If you're looking for React Server Component and Next.js docs, they're in the next-sanity readme.

Live real-time preview for React

Note

The examples in this README use Remix, you can find Next.js specific examples in the next-sanity README. Including information on how to build live previews in React Server Components with the new app-router.

Write GROQ queries like @sanity/client and have them resolve in-memory, locally. Updates from Content Lake are streamed in real-time with sub-second latency.

Requires React 18, support for other libraries like Solid, Svelte, Vue etc are planned. For now you can use @sanity/groq-store directly.

Get started in 3 steps:

1. Create a client instance of @sanity/client that can be shared on the server and browser.
2. Define a <LiveQueryProvider /> configuration.
3. Refactor the root layout of your app to conditionally wrap it in <LiveQueryProvider /> when it's asked to preview drafts.
4. Use the useLiveQuery hook in components that you want to re-render in real-time as your documents are edited.

1. Create a client instance

As <LiveQueryProvider /> is configured with a @sanity/client instance it makes sense to create a utility for it. Doing so makes it easy to ensure the server-side and client-side client are configured the same way.

app/lib/sanity.ts

import { createClient } from '@sanity/client'
import type { QueryParams } from '@sanity/client'

// Shared on the server and the browser
export const client = createClient({
  projectId: 'your-project-id',
  dataset: 'production',
  apiVersion: '2023-06-20',
  useCdn: false,
  perspective: 'published',
})

// Only defined on the server, passed to the browser via a `loader`
export const token =
  typeof process === 'undefined' ? '' : process.env.SANITY_API_READ_TOKEN!

const DEFAULT_PARAMS = {} as QueryParams

// Utility for fetching data on the server, that can toggle between published and preview drafts
export async function sanityFetch<QueryResponse>({
  previewDrafts,
  query,
  params = DEFAULT_PARAMS,
}: {
  previewDrafts?: boolean
  query: string
  params?: QueryParams
}): Promise<QueryResponse> {
  if (previewDrafts && !token) {
    throw new Error(
      'The `SANITY_API_READ_TOKEN` environment variable is required.',
    )
  }
  return client.fetch<QueryResponse>(
    query,
    params,
    previewDrafts
      ? {
          token,
          perspective: 'previewDrafts',
        }
      : {},
  )
}

2. Define a <LiveQueryProvider /> component

Create a new file for the provider, so it can be loaded with React.lazy and avoid increasing the bundle size in production. Ensuring code needed for live previewing drafts are only loaded when needed.

app/PreviewProvider.tsx

import { LiveQueryProvider } from '@sanity/preview-kit'
import { client } from '~/lib/sanity'

export default function PreviewProvider({
  children,
  token,
}: {
  children: React.ReactNode
  token: string
}) {
  if (!token) throw new TypeError('Missing token')
  return (
    <LiveQueryProvider client={client} token={token}>
      {children}
    </LiveQueryProvider>
  )
}

Only the client and token props are required. For debugging you can pass a logger={console} prop.

You can also use the useIsEnabled hook to debug wether you have a parent <LiveQueryProvider /> in your React tree or not.

3. Making a Remix route conditionally preview drafts

Here's the Remix route we'll be adding live preview of drafts, it's pretty basic:

// app/routes/index.tsx
import type { LoaderArgs } from '@vercel/remix'
import { useLoaderData } from '@remix-run/react'

import { client } from '~/lib/sanity'
import type { UsersResponse } from '~/UsersList'
import { UsersList, usersQuery } from '~/UsersList'
import { Layout } from '~/ui'

export async function loader({ request }: LoaderArgs) {
  const url = new URL(request.url)
  const lastId = url.searchParams.get('lastId') || ''

  const users = await client.fetch<UsersResponse>(usersQuery, { lastId })

  return { users, lastId }
}

export default function Index() {
  const { users, lastId } = useLoaderData<typeof loader>()

  return (
    <Layout>
      <UsersList data={users} lastId={lastId} />
    </Layout>
  )
}

Now let's import the PreviewProvider component we created in the previous step. To ensure we don't increase the production bundle size, we'll use React.lazy to code-split the component. The React.lazy API requires a React.Suspense boundary, so we'll add that too.

import { lazy, Suspense } from 'react'

const PreviewProvider = lazy(() => import('~/PreviewProvider'))

Before we can add <PreviewProvider /> to the layout we need to update the loader to include the props it needs. We'll use an environment variable called SANITY_API_PREVIEW_DRAFTS to control when to live preview drafts, and store a viewer API token in SANITY_API_READ_TOKEN.

Update the client.fetch call to use the new sanityFetch utility we created earlier, as well as the token:

import { token, sanityFetch } from '~/lib/sanity'

const previewDrafts = process.env.SANITY_API_PREVIEW_DRAFTS === 'true'
const users = await sanityFetch<UsersResponse>({
  previewDrafts,
  query: usersQuery,
  params: { lastId },
})

Update the loader return statement from return {users, lastId} to:

return { previewDrafts, token, users, lastId }

And add previewDrafts, and token, to useLoaderData:

const { previewDrafts, token, users, lastId } = useLoaderData<typeof loader>()

Then make the render conditional based on wether previewDrafts is set:

const children = <UsersList data={users} lastId={lastId} />

return (
  <Layout>
    {previewDrafts ? (
      <Suspense fallback={children}>
        <PreviewProvider token={token}>{children}</PreviewProvider>
      </Suspense>
    ) : (
      children
    )}
  </Layout>
)

After putting everything together the route should now look like this:

// app/routes/index.tsx
import type { LoaderArgs } from '@vercel/remix'
import { useLoaderData } from '@remix-run/react'
import { lazy, Suspense } from 'react'

import { token, sanityFetch } from '~/lib/sanity'
import type { UsersResponse } from '~/UsersList'
import { UsersList, usersQuery } from '~/UsersList'
import { Layout } from '~/ui'

const PreviewProvider = lazy(() => import('~/PreviewProvider'))

export async function loader({ request }: LoaderArgs) {
  const previewDrafts =
    process.env.SANITY_API_PREVIEW_DRAFTS === 'true' ? { token } : undefined
  const url = new URL(request.url)
  const lastId = url.searchParams.get('lastId') || ''

  const users = await sanityFetch<UsersResponse>({
    previewDrafts,
    query: usersQuery,
    params: { lastId },
  })

  return { previewDrafts, token, users, lastId }
}

export default function Index() {
  const { previewDrafts, token, users, lastId } = useLoaderData<typeof loader>()

  const children = <UsersList data={users} lastId={lastId} />

  return (
    <Layout>
      {previewDrafts ? (
        <Suspense fallback={children}>
          <PreviewProvider token={token!}>{children}</PreviewProvider>
        </Suspense>
      ) : (
        children
      )}
    </Layout>
  )
}

4. Adding the useLiveQuery hook to components that need to re-render in real-time

Let's look at what the <UsersList> component looks like, before we add the hook:

// app/UsersList.tsx
import groq from 'groq'

import { ListView, ListPagination } from '~/ui'

export const usersQuery = groq`{
  "list": *[_type == "user" && _id > $lastId] | order(_id) [0...20],
  "total": count(*[_type == "user"]),
}`

export interface UsersResponse {
  list: User[]
  total: number
}

export interface UsersListProps {
  data: UsersResponse
  lastId: string
}

export function UsersList(props: UsersListProps) {
  const { data, lastId } = props

  return (
    <>
      <ListView list={data.list} />
      <ListPagination total={data.total} lastId={lastId} />
    </>
  )
}

To make this component connect to your preview provider you need to add the useLiveQuery. You don't have to refactor your components so that the hook is only called when there's a parent <LiveQueryProvider />, it's safe to call it unconditionally. If there's no <LiveQueryProvider /> it behaves as if the hook had this implementation:

export function useLiveQuery(initialData) {
  return [initialData, false]
}

Thus it's fairly easy to add conditional live preview capabilities to UsersList, simply add hook to your imports:

import { useLiveQuery } from '@sanity/preview-kit'

And replace this:

const { data, lastId } = props

With this:

const { data: initialData, lastId } = props
const [data] = useLiveQuery(initialData, usersQuery, { lastId })

All together now:

// app/UsersList.tsx
import { useLiveQuery } from '@sanity/preview-kit'
import groq from 'groq'

import { ListView, ListPagination } from '~/ui'

export const usersQuery = groq`{
  "list": *[_type == "user" && _id > $lastId] | order(_id) [0...20],
  "total": count(*[_type == "user"]),
}`

export interface UsersResponse {
  list: User[]
  total: number
}

export interface UsersListProps {
  data: UsersResponse
  lastId: string
}

export function UsersList(props: UsersListProps) {
  const { data: initialData, lastId } = props
  const [data] = useLiveQuery(initialData, usersQuery, { lastId })

  return (
    <>
      <ListView list={data.list} />
      <ListPagination total={data.total} lastId={lastId} />
    </>
  )
}

And done! You can optionally optimize it further by adding a loading UI while it loads, or improve performance by adding a custom isEqual function to reduce React re-renders if there's a lot of data that changes but isn't user visible (SEO metadata and such).

Implementing a Loading UI with useLiveQuery

The best way to do this is to add a wrapper component that is only used in preview mode that calls the useLiveQuery hook.

export function UsersList(props: UsersListProps) {
  const { data, lastId } = props

  return (
    <>
      <ListView list={data.list} />
      <ListPagination total={data.total} lastId={lastId} />
    </>
  )
}

export function PreviewUsersList(props: UsersListProps) {
  const { data: initialData, lastId } = props
  const [data, loading] = useLiveQuery(initialData, usersQuery, { lastId })

  return (
    <>
      <PreviewStatus loading={loading} />
      <UsersList data={users} lastId={lastId} />
    </>
  )
}

Change the layout from:

const children = <UsersList data={users} lastId={lastId} />

return (
  <Layout>
    {preview ? (
      <Suspense fallback={children}>
        <PreviewProvider token={preview.token!}>{children}</PreviewProvider>
      </Suspense>
    ) : (
      children
    )}
  </Layout>
)

To this:

return (
  <Layout>
    {preview ? (
      <Suspense fallback={children}>
        <PreviewProvider token={preview.token!}>
          <PreviewUsersList data={users} lastId={lastId} />
        </PreviewProvider>
      </Suspense>
    ) : (
      <UsersList data={users} lastId={lastId} />
    )}
  </Layout>
)

Optimizing performance

Out of the box it'll only trigger a re-render of UsersList if the query response changed, using react-fast-compare under the hood. You can tweak this behavior by passing a custom isEqual function as the third argument to useLiveQuery if there's only some changes you want to trigger a re-render.

const [data] = useLiveQuery(
  initialData,
  usersQuery,
  { lastId },
  {
    // Only re-render in real-time if user ids and names changed, ignore all other differences
    isEqual: (a, b) =>
      a.list.every((aItem, index) => {
        const bItem = b.list[index]
        return aItem._id === bItem._id && aItem.name === bItem.name
      }),
  },
)

You can also use the React.useDeferredValue hook and a React.memo wrapper to further optimize performance by letting React give other state updates higher priority than the preview updates. It prevents the rest of your app from slowing down should there be too much Studio activity for the previews to keep up with:

import { memo, useDeferredValue } from 'react'

export function PreviewUsersList(props: UsersListProps) {
  const { data: initialData, lastId } = props
  const [snapshot] = useLiveQuery(initialData, usersQuery, { lastId })
  const data = useDeferredValue(snapshot)

  return <UsersList data={data} lastId={lastId} />
}

export const UsersList = memo(function UsersList(props: UsersListProps) {
  const { data, lastId } = props

  return (
    <>
      <ListView list={data.list} />
      <ListPagination total={data.total} lastId={lastId} />
    </>
  )
})

Advanced usage

Using the LiveQuery wrapper component instead of the useLiveQuery hook

The main benefit of the LiveQuery wrapper, over the useLiveQuery hook, is that it implements lazy loading. Unless enabled the code for useLiveQuery isn't loaded and your application's bundlesize isn't increased in production.

import { LiveQuery } from '@sanity/preview-kit/live-query'

const UsersList = memo(function UsersList(props: UsersListProps) {
  const { data, lastId } = props

  return (
    <>
      <ListView list={data.list} />
      <ListPagination total={data.total} lastId={lastId} />
    </>
  )
})

export default function Layout(props: LayoutProps) {
  return (
    <LiveQuery
      enabled={props.preview}
      query={usersQuery}
      params={{ lastId: props.lastId }}
      initialData={props.data}
    >
      <UsersList
        // LiveQuery will override the `data` prop with the real-time data when live previews are enabled
        data={props.data}
        // But other props will be passed through
        lastId={props.lastId}
      />
    </LiveQuery>
  )
}

For React Server Components it's important to note that the children of LiveQuery must be a use client component. Otherwise it won't be able to re-render as the data prop changes. The as prop can be used to make sure the component is only used as a client component when live previews are enabled, below is an example of how this is done in the Next.js App Router, using 3 separate files:

app/users/[lastId]/UsersList.tsx:

// This component in itself doesn't have any interactivity and can be rendered on the server, and avoid adding to the browser bundle.

export default function UsersList(props: UsersListProps) {
  const { data, lastId } = props

  return (
    <>
      <ListView list={data.list} />
      <ListPagination total={data.total} lastId={lastId} />
    </>
  )
}

app/users/[lastId]/UsersListPreview.tsx:

'use client'

import dynamic from 'next/dynamic'

// Re-exported components using next/dynamic ensures they're not bundled
// and sent to the browser unless actually used, with draftMode().enabled.

export default dynamic(() => import('./UsersList'))

app/users/[lastId]/page.tsx

import { createClient } from '@sanity/client'
import { LiveQuery } from '@sanity/preview-kit/live-query'
import { draftMode } from 'next/headers'
import UsersList from './UsersList'
import UsersListPreview from './UsersListPreview'

const client = createClient({
  // standard client config
})

export default async function UsersPage(params) {
  const { lastId } = params
  const data = await client.fetch(
    usersQuery,
    { lastId },
    { perspective: draftMode().isEnabled ? 'previewDrafts' : 'published' },
  )

  return (
    <LiveQuery
      enabled={draftMode().isEnabled}
      query={usersQuery}
      params={{ lastId }}
      initialData={data}
      as={UsersListPreview}
    >
      <UsersList
        data={data}
        // LiveQuery ensures that the `lastId` prop used here is applied to `UsersListPreview` as well
        lastId={lastId}
      />
    </LiveQuery>
  )
}

What's great about this setup is that UsersList is rendering only on the server by default, but when live previews are enabled the UsersListPreview repackages it to a client component so it's able to re-render in the browser in real-time as the data changes. It's the closest thing to having your cake and eating it too.

Trouble-shooting and debugging

As the nature of live queries is that they're real-time, it can be hard to debug issues. Is nothing happening because no edits happened? Or because something isn't setup correctly? To aid in understanding what's going on, you can pass a logger prop to LiveQueryProvider:

<LiveQueryProvider client={client} token={token} logger={console}>
  {children}
</LiveQueryProvider>

You'll now get detailed reports on how it's setup and what to expect in terms of how it responds to updates. For example in large datasets it may use a polling interval instead of running GROQ queries on a complete local cache of your dataset.

You can also use the useIsEnabled hook to determine of a live component (something that uses useLiveQuery) has a LiveQueryProvider in the parent tree or not:

import { useLiveQuery, useIsEnabled } from '@sanity/preview-kit'

export function PreviewUsersList(props) {
  const [data] = useLiveQuery(props.data, query, params)
  const isLive = useIsEnabled()

  if (!isLive) {
    throw new TypeError('UsersList is not wrapped in a LiveQueryProvider')
  }

  return <UsersList data={data} />
}

If it's always false it's an indicator that you may need to lift your LiveQueryProvider higher up in the tree. Depending on the framework it's recommended that you put it in:

• Remix: src/app/routes/index.tsx
• Next App Router: src/app/layout.tsx
• Next Pages Router: src/pages/_app.tsx

Content Source Map features

For data that can't be traced with Content Source Maps there's a background refresh interval. Depending on your queries you might want to tweak this interval to get the best performance.

import { LiveQueryProvider } from '@sanity/preview-kit'

return (
  <LiveQueryProvider
    client={client}
    token={token}
    // Refetch all queries every minute instead of the default 10 seconds
    refreshInterval={1000 * 60}
    // Passing a logger gives you more information on what to expect based on your configuration
    logger={console}
  >
    {children}
  </LiveQueryProvider>
)

@sanity/preview-kit/client

Visual Editing with Content Source Maps

Note

Content Source Maps are available as an API for select Sanity enterprise customers. Contact our sales team for more information.

You can use Visual Editing with any framework, not just React. Read our guide for how to get started.

Enhanced Sanity client with createClient

Preview Kit's enhanced Sanity client is built on top of @sanity/client and is designed to be a drop-in replacement. It extends the client configuration with options for returning encoded metadata from Content Source Maps.

// Remove your vanilla `@sanity/client` import
// import {createClient, type ClientConfig} from '@sanity/client'

// Use the enhanced client instead
import { createClient, type ClientConfig } from '@sanity/preview-kit/client'

const config: ClientConfig = {
  // ...base config options

  // Required: when "encodeSourceMap" is enabled
  // Set it to relative or absolute URL of your Sanity Studio
  studioUrl: '/studio', // or 'https://your-project-name.sanity.studio'

  // Required: for encoded metadata from Content Source Maps
  // 'auto' is the default, you can also use `true` or `false`
  encodeSourceMap: 'auto',
}

const client = createClient(config)

studioUrl

Required when encodeSourceMap is active, and can either be an absolute URL:

import { createClient } from '@sanity/preview-kit/client'

const client = createClient({
  ...config,
  studioUrl: 'https://your-company.com/studio',
})

Or a relative path if the Studio is hosted on the same deployment, or embedded in the same app:

import { createClient } from '@sanity/preview-kit/client'

const client = createClient({
  ...config,
  studioUrl: '/studio',
})

encodeSourceMap

Accepts "auto", the default, or a boolean. Controls when to encode the content source map into strings using @vercel/stega encoding. When "auto" is used a best-effort environment detection is used to see if the environment is a Vercel Preview deployment. On a different hosting provider, or in local development, configure this option to make sure it is only enabled in non-production deployments.

import { createClient } from '@sanity/preview-kit/client'

const client = createClient({
  ...config,
  encodeSourceMap: process.env.VERCEL_ENV === 'preview',
})

encodeSourceMapAtPath

By default source maps are encoded into all strings that can be traced back to a document field, except for URLs and ISO dates. We also make some exceptions for fields like, document._type, document._id and document.slug.current, that we've seen leading to breakage if the string is altered as well as for Portable Text.

You can customize this behavior using encodeSourceMapAtPath:

import { createClient } from '@sanity/preview-kit/client'

const client = createClient({
  ...config,
  encodeSourceMapAtPath: (props) => {
    if (props.path[0] === 'externalUrl') {
      return false
    }
    // The default behavior is packaged into `filterDefault`, allowing you enable encoding fields that are skipped by default
    return props.filterDefault(props)
  },
})

logger

Pass a console into logger to get detailed debug info and reports on which fields are encoded and which are skipped:

import { createClient } from '@sanity/preview-kit/client'

const client = createClient({
  ...config,
  logger: console,
})

An example report:

[@sanity/preview-kit/client]: Creating source map enabled client
[@sanity/client/stega]: Stega encoding source map into result
  [@sanity/client/stega]: Paths encoded: 3, skipped: 17
  [@sanity/client/stega]: Table of encoded paths
  ┌─────────┬──────────────────────────────┬───────────────────────────┬────────┐
  │ (index) │              path            │           value           │ length │
  ├─────────┼──────────────────────────────┼───────────────────────────┼────────┤
  │    0    │ "footer[0].children[0].text" │ '"The future is alrea...' │   67   │
  │    1    │ "footer[1].children[0].text" │     'Robin Williams'      │   14   │
  │    2    │            "title"           │     'Visual Editing'      │   14   │
  └─────────┴──────────────────────────────┴───────────────────────────┴────────┘
  [@sanity/client/stega]: List of skipped paths [
    'footer[]._key',
    'footer[].children[]._key',
    'footer[].children[]._type',
    'footer[]._type',
    'footer[].style',
    '_type',
    'slug.current',
  ]

resultSourceMap

This option is always enabled if encodeSourceMap. It's exposed here to be compatible with @sanity/client and custom use cases where you want content source maps, but not the encoding.

const client = createClient({
  ...config,
  // This option can only enable content source maps, not disable it when `encodeSourceMap` resolves to `true`
  resultSourceMap: true,
})

const { result, resultSourceMap } = await client.fetch(query, params, {
  filterResponse: false,
})

console.log(resultSourceMap) // `resultSourceMap` is now available, even if `encodeSourceMap` is `false`

Using Perspectives

The perspective option can be used to specify special filtering behavior for queries. The default value is raw, which means no special filtering is applied, while published and previewDrafts can be used to optimize for specific use cases. Read more about this option:

• Perspectives in Sanity docs
• Perspectives in @sanity/client README

Release new version

Run "CI & Release" workflow. Make sure to select the main branch and check "Release new version".

Semantic release will only release on configured branches, so it is safe to run release on any branch.

License

MIT-licensed. See LICENSE.