Bug Report: Unleash Next.js Integration Issue - "body has already been consumed" Error in Server Components

Environment Details

• @unleash/nextjs: 1.4.4
• Next.js: 14.2.7
• React: 18.2.0
• TypeScript: 5.4.5
• Deployment Platform: Vercel

Questions for the Unleash Team

1. Is version 1.4.4 of @unleash/nextjs fully compatible with Next.js 14's server components?
2. Are there known issues with body consumption in server component contexts?
3. Are there recommended patterns for using Unleash with Next.js 14 server components?

Steps to reproduce the bug

1. Set up a Next.js 14 project with App Router and Server Components
2. Integrate @unleash/nextjs version 1.4.4
3. Implement feature flag checking in a server component
4. Attempt to render the component with feature flag validation
5. Deploy the project to Vercel

Expected behavior

• The server should successfully check feature flags during server-side rendering
• The component should render without any body consumption errors
• Feature flags should be evaluated correctly

Actual Behaviour :

• Server throws "body has already been consumed" error
• The error appears to be related to how request bodies are handled during server-side rendering
• Possible performance issues or race conditions with Unleash flag evaluation

Logs, error output, etc.

Error checking feature access: TypeError: Response.clone: Body has already been consumed.
    at webidl.errors.exception (node:internal/deps/undici/undici:3384:14)
    at _Response.clone (node:internal/deps/undici/undici:8883:31)
    at /var/task/node_modules/.pnpm/next@14.2.7_@babel+core@7.25.2_@opentelemetry+api@1.9.0_@playwright+test@1.48.1_react-dom@18._s6i3mmeecyghkm4uajs4djv4gi/node_modules/next/dist/compiled/next-server/app-page.runtime.prod.js:12:181023

Error: Error checking feature access: TypeError: Response.clone: Body has already been consumed.
    at i (/var/task/apps/core-web/.next/server/app/[locale]/copilots/create/page.js:1:6334)
    at async /var/task/apps/core-web/.next/server/app/[locale]/copilots/settings/official/page.js:1:3502

Screenshots

No response

Additional context

No response

Unleash version

1.4.4

Subscription type

Open source

Hosting type

Self-hosted

SDK information (language and version)

No response