vercel/next.js · error · Error

${apiName} was used inside a Server Action. This is not supp

Error message

${apiName} was used inside a Server Action. This is not supported. Functions from 'next/root-params' can only be called in the context of a route.

What it means

Scope check in getRootParam: the accessor ran during the action phase of a Server Action. Actions are not bound to a single route (one action can be submitted from multiple roots), so root params would be ambiguous there and the call is rejected during that phase only — rerenders after revalidation still pass.

Source

Thrown at packages/next/src/server/request/root-params.ts:48

    throw new Error(
      `Route ${workStore.route} used ${apiName} outside of a Server Component. This is not allowed.`
    )
  }

  const actionStore = actionAsyncStorage.getStore()
  if (actionStore) {
    if (actionStore.isAppRoute) {
      // TODO(root-params): add support for route handlers
      throw new Error(
        `Route ${workStore.route} used ${apiName} inside a Route Handler. Support for this API in Route Handlers is planned for a future version of Next.js.`
      )
    }
    if (actionStore.isAction && workUnitStore.phase === 'action') {
      // Actions are not fundamentally tied to a route (even if they're always submitted from some page),
      // so root params would be inconsistent if an action is called from multiple roots.
      // Make sure we check if the phase is "action" - we should not error in the rerender
      // after an action revalidates or updates cookies (which will still have `actionStore.isAction === true`)
      throw new Error(
        `${apiName} was used inside a Server Action. This is not supported. Functions from 'next/root-params' can only be called in the context of a route.`
      )
    }
  }

  switch (workUnitStore.type) {
    case 'unstable-cache': {
      throw new Error(
        `Route ${workStore.route} used ${apiName} inside \`unstable_cache\`. This is not supported. Use \`"use cache"\` instead.`
      )
    }
    case 'cache': {
      if (!workUnitStore.rootParams) {
        throw new Error(
          `Route ${workStore.route} used ${apiName} inside \`"use cache"\` nested within \`unstable_cache\`. Root params are not available in this context.`
        )
      }
      workUnitStore.readRootParamNames.add(paramName)

View on GitHub (pinned to 0eb3775416)

Solutions

1. Do not call next/root-params functions inside Server Actions; pass the values as arguments.

When it happens

Trigger: A root-params API is called inside a Server Action.

Common situations: Using next/root-params within a 'use server' function, which lacks route context.

AI-assisted analysis of vercel/next.js@0eb3775416 (2026-08-19). Data as JSON: /api/errors/be0f304ebc29e4e7. Report an issue: GitHub.