What causes "No worker function found for ${job.name}" in gatsbyjs/gatsby?

Ensure gatsby-worker.js exports a function whose name exactly equals the enqueued job.name.

No worker function found for ${job.name}

Error message

No worker function found for ${job.name}

What it means

runJob dynamically imports the plugin's gatsby-worker module and indexes it by job.name. If no exported function with that name exists, it throws. The job name must exactly match a named export of the plugin's gatsby-worker.js.

Source

Thrown at packages/gatsby/src/utils/jobs/manager.ts:162

  process.send!(jobCreatedMessage)

  return deferred.promise
}

/**
 * Make sure we have everything we need to run a job
 * If we do, run it locally.
 * TODO add external job execution through ipc
 */
function runJob(
  job: InternalJob,
  forceLocal = false
): Promise<Record<string, unknown>> {
  const { plugin } = job
  try {
    return importGatsbyPlugin(plugin, `gatsby-worker`).then(worker => {
      if (!worker[job.name]) {
        throw new Error(`No worker function found for ${job.name}`)
      }

      if (!forceLocal && !job.plugin.isLocal && hasExternalJobsEnabled()) {
        if (process.send) {
          if (!isListeningForMessages) {
            isListeningForMessages = true
            listenForJobMessages()
          }

          return runExternalWorker(job)
        } else {
          // only show the offloading warning once
          if (!hasShownIPCDisabledWarning) {
            hasShownIPCDisabledWarning = true
            reporter.warn(
              `Offloading of a job failed as IPC could not be detected. Running job locally.`
            )
          }

View on GitHub (pinned to 8b06340921)

Solutions

Ensure gatsby-worker.js exports a function whose name exactly equals the enqueued job.name.
Update the plugin to a version whose worker exports match the job name.
Fix the casing/spelling of the job name at the enqueue call site.

Example fix

// before: enqueue uses 'PROCESS_IMAGE', worker exports 'processImage'
// gatsby-worker.js
module.exports = { processImage: require('./worker').processImage }
// after: align names
module.exports = { PROCESS_IMAGE: require('./worker').processImage }

Defensive patterns

Strategy: validation

Validate before calling

async function workerHasJob(plugin, jobName) {
  const worker = await importGatsbyPlugin(plugin, 'gatsby-worker')
  return typeof worker[jobName] === 'function'
}

Type guard

function workerExportsJob(worker, name) { return typeof worker?.[name] === 'function' }

Prevention

Keep job names and worker export names identical and in a shared constants module.
Add a unit test asserting the worker exports every job name the plugin enqueues.
Version plugins so job/worker names stay in sync across releases.

When it happens

Trigger: A plugin queues a job whose name does not match a named export in its gatsby-worker.js (e.g. enqueueing 'PROCESS_IMAGE' but the worker exports 'processImage').

Common situations: Plugin version mismatch (job renamed across versions); typo in job name; renamed worker export without updating enqueue sites.

Related errors

AI-assisted analysis of gatsbyjs/gatsby@8b06340921 (2026-08-13). Data as JSON: /api/errors/99cc2127ce40a5fa. Report an issue: GitHub.