gatsbyjs/gatsby · error

createNodeId must be a function, was ${typeof createNodeId}

Error message

createNodeId must be a function, was ${typeof createNodeId}

What it means

The gatsby-source-wordpress vendored copy of createRemoteFileNode validates createNodeId exactly like the upstream gatsby-source-filesystem version. After URL encoding, it asserts typeof createNodeId === 'function'. Non-function values are rejected with their runtime type. This guard is the first of three input validations (createNodeId, createNode, cache).

Source

Thrown at packages/gatsby-source-wordpress/src/steps/source-nodes/create-nodes/create-remote-file-node/index.js:406

  if (doneQueueTimeout) {
    // this is to give the bar a little time to wait when there are pauses
    // between file downloads.
    clearTimeout(doneQueueTimeout)
  }

  // if the url isn't already encoded
  // so decoding it doesn't do anything
  if (decodeURI(url) === url) {
    // encode the uri
    // this accounts for special characters in filenames
    url = encodeURI(url)
  }

  // validation of the input
  // without this it's notoriously easy to pass in the wrong `createNodeId`
  // see gatsbyjs/gatsby#6643
  if (typeof createNodeId !== `function`) {
    throw new Error(
      `createNodeId must be a function, was ${typeof createNodeId}`
    )
  }
  if (typeof createNode !== `function`) {
    throw new Error(`createNode must be a function, was ${typeof createNode}`)
  }
  if (typeof getCache === `function`) {
    // use cache of this plugin and not cache of function caller
    cache = getCache(`gatsby-source-filesystem`)
  }
  if (typeof cache !== `object`) {
    throw new Error(
      `Neither "cache" or "getCache" was passed. getCache must be function that return Gatsby cache, "cache" must be the Gatsby cache, was ${typeof cache}`
    )
  }

  // Check if we already requested node for this remote file
  // and return stored promise if we did.

View on GitHub (pinned to 8b06340921)

Solutions

1. If you are a user, this is almost always a gatsby-source-wordpress internal bug — upgrade to the latest version.
2. If forking, ensure createNodeId is forwarded from helpers into the createRemoteFileNode call site.
3. Verify your Gatsby version is compatible with the gatsby-source-wordpress version in use.
4. Check that WPGQL is actually returning media items; an upstream change should not remove createNodeId but a stale cache of helpers can.

Example fix

null

if (typeof createNodeId !== 'function') { throw new TypeError('createNodeId not available in the WordPress media step') }

const isCreateNodeId = (v) => typeof v === 'function'

null

When it happens

Trigger: gatsby-source-wordpress calling its internal createRemoteFileNode without forwarding createNodeId; a custom integration passing createNodeId: undefined; calling the function directly from user code without Gatsby helpers.

Common situations: Internal plugin bug where helpers were not threaded through to the media step; forking gatsby-source-wordpress and dropping the createNodeId forwarding; version mismatch between gatsby-source-wordpress and Gatsby core that changes helper availability.

Related errors

• createNodeId must be a function, was ${typeof createNodeId}
• createNode must be a function, was ${typeof createNode}
• Neither "cache" or "getCache" was passed. getCache must be f
• Invalid plugin options for "gatsby-plugin-sitemap":
• The "layout" argument is required for "${source.url}"

AI-assisted analysis of gatsbyjs/gatsby@8b06340921 (2026-08-13). Data as JSON: /api/errors/8b482d3f03dfa103. Report an issue: GitHub.