The NEXT_DEPLOYMENT_ID environment variable value "${process

Error message

The NEXT_DEPLOYMENT_ID environment variable value "${process.env.NEXT_DEPLOYMENT_ID}" does not match the provided deploymentId "${result.deploymentId}" in the config.

What it means

During a production build (`PHASE_PRODUCTION_BUILD`) on a CI platform with Next.js support, if `process.env.NEXT_DEPLOYMENT_ID` is set and the config also provides `deploymentId`, the two must match exactly (config.ts:1131-1144). The env var is the platform's source of truth for the deployment identity, and a mismatch would cause cache invalidation and asset path bugs.

Source

Thrown at packages/next/src/server/config.ts:1141

  if (result?.turbopack?.chunkLoadingGlobal) {
    const g = result.turbopack.chunkLoadingGlobal
    if (!g.startsWith('TURBOPACK_')) {
      result.turbopack.chunkLoadingGlobal = `TURBOPACK_${g}`
    }
  }

  if (
    result.experimental.runtimeServerDeploymentId == null &&
    phase === PHASE_PRODUCTION_BUILD &&
    ciEnvironment.hasNextSupport &&
    process.env.NEXT_DEPLOYMENT_ID
  ) {
    if (
      result.deploymentId != null &&
      result.deploymentId !== process.env.NEXT_DEPLOYMENT_ID
    ) {
      throw new Error(
        `The NEXT_DEPLOYMENT_ID environment variable value "${process.env.NEXT_DEPLOYMENT_ID}" does not match the provided deploymentId "${result.deploymentId}" in the config.`
      )
    }
    result.experimental.runtimeServerDeploymentId = true
  }

  // only leverage deploymentId
  if (process.env.NEXT_DEPLOYMENT_ID) {
    result.deploymentId = process.env.NEXT_DEPLOYMENT_ID
  }

  if (process.env.NEXT_HASH_SALT) {
    result.outputHashSalt =
      (result.outputHashSalt ?? '') + (process.env.NEXT_HASH_SALT ?? '')
  }

  const tracingRoot = result?.outputFileTracingRoot
  const turbopackRoot = result?.turbopack?.root

View on GitHub (pinned to 0ae8c72462)

Solutions

Remove the hardcoded `deploymentId` from next.config and let the platform drive it via NEXT_DEPLOYMENT_ID.
Or align the config value with the env var exactly.
Confirm ciEnvironment detection is intended; if you don't want platform-managed IDs, unset NEXT_DEPLOYMENT_ID in CI.

Example fix

// before
module.exports = { deploymentId: 'abc123' }  // env: NEXT_DEPLOYMENT_ID=xyz789
// after
module.exports = {}  // let NEXT_DEPLOYMENT_ID drive deploymentId

Defensive patterns

Strategy: validation

Validate before calling

if (process.env.NEXT_DEPLOYMENT_ID && config.deploymentId && config.deploymentId !== process.env.NEXT_DEPLOYMENT_ID) {
  throw new Error(`deploymentId ${config.deploymentId} != NEXT_DEPLOYMENT_ID ${process.env.NEXT_DEPLOYMENT_ID}`);
}

Prevention

Avoid hardcoding deploymentId in config; let the platform set NEXT_DEPLOYMENT_ID.
In CI, fail fast in a pre-build step if the two diverge.

When it happens

Trigger: Hardcoding `deploymentId: 'abc123'` in next.config while deploying to a platform that sets `NEXT_DEPLOYMENT_ID=xyz789` (e.g. Vercel or a self-hosted platform emulating it). Only triggers when both values are present and differ during a production build with `ciEnvironment.hasNextSupport`.

Common situations: Copying a deploymentId from one environment into config used in another. Setting NEXT_DEPLOYMENT_ID in CI secrets while a stale deploymentId sits in the repo. Promoting a build artifact across deployment IDs.

Related errors

AI-assisted analysis of vercel/next.js@0ae8c72462 (2026-08-06). Data as JSON: /api/errors/633e82b8662e9c70. Report an issue: GitHub.