gatsbyjs/gatsby · error · Error

createSlice is only available in Gatsby v5

Error message

createSlice is only available in Gatsby v5

What it means

The createSlice action (slices are partial-hydration component boundaries introduced in Gatsby v5) is gated behind a version check; on Gatsby v4 and earlier the restricted action creator throws unconditionally because the slice machinery, redux slices state, and rendering pipeline do not exist. The throw sits in the else-branch of the version-gated createSlice implementation in restricted.ts.

Source

Thrown at packages/gatsby/src/redux/actions/restricted.ts:532

        type: `CREATE_SLICE`,
        plugin,
        payload: {
          componentChunkName: generateComponentChunkName(
            payload.component,
            `slice`
          ),
          componentPath,
          // note: we use "name" internally instead of id
          name: payload.id,
          context: payload.context || {},
          updatedAt: Date.now(),
        },
        traceId,
        componentModified,
        contextModified,
      }
    } else {
      throw new Error(`createSlice is only available in Gatsby v5`)
    }
  },
  /**
   * Declares URL Pattern that should be allowed to be used for Image or File CDN to prevent using of unexpected RemoteFile URLs.
   *
   * @availableIn [onPreInit, onPreBootstrap, onPluginInit, createSchemaCustomization]
   *
   * @param {string | string []} url URLPattern or Array of URL Patternss that should be allowed.
   * URLPattern is a string that can contain wildcards (*) or parameter placeholders (e.g. :id).
   * @example
   * exports.onPreInit = ({ actions }) => {
   *   actions.addRemoteFileAllowedUrl(`https://your-wordpress-instance.com/*`)
   * }
   */
  addRemoteFileAllowedUrl: (
    url: string | Array<string>,
    plugin: IGatsbyPlugin,
    traceId?: string

View on GitHub (pinned to 8b06340921)

Solutions

1. Upgrade the project to Gatsby v5: `npm i gatsby@latest` (and follow the v4->v5 migration guide for Node >= 18.15, React 18, etc.).
2. If you cannot upgrade, pin/downgrade the offending theme or plugin to a version that supports Gatsby v4 (no createSlice usage).
3. Remove or guard the createSlice call if it is in your own code and you are not on v5.

Example fix

// before - gatsby-node.js on Gatsby v4
exports.createPages = ({ actions }) => {
  actions.createSlice({ id: `header`, component: require.resolve(`./src/slices/header`) })
}
// after - upgrade to Gatsby v5, or remove the call
// package.json: "gatsby": "^5.0.0"

// Gate createSlice usage on the running Gatsby major version.
const gatsbyPkg = require('gatsby/package.json')
const major = Number(gatsbyPkg.version.split('.')[0])
function safeCreateSlice(actions, args) {
  if (major < 5) {
    console.warn('createSlice skipped: requires Gatsby v5+')
    return
  }
  return actions.createSlice(args)
}

function supportsSlices() {
  const v = require('gatsby/package.json').version
  return Number(v.split('.')[0]) >= 5
}

When it happens

Trigger: Calling actions.createSlice(...) (directly or via a plugin/theme that uses slices) while running Gatsby < 5.0.0. The action creator is defined but the v5 code path is not taken, so the else-branch throws.

Common situations: Installing a theme/plugin authored against Gatsby v5 (e.g. one calling createSlice in gatsby-node/gatsby-browser) into a project still on Gatsby v4; upgrading the theme but not the gatsby package; using a starter that targets v5 on an older lockfile.

Related errors

• generateImageSource must be a function
• GatsbySortAndAggrCodemod: GraphQL syntax error in query: ${
• Plugins creating nodes can not set data on the reserved fiel
• A plugin tried to update a node field that it doesn't own:
• An ID must be provided when creating or setting job

AI-assisted analysis of gatsbyjs/gatsby@8b06340921 (2026-08-13). Data as JSON: /api/errors/0e4cd55e19b53587. Report an issue: GitHub.