Tailwind CSS 4 Integration Fails with ESM Errors

[ThisIsMrAli]

Description

When attempting to integrate Tailwind CSS 4 with a Bolt-CEP project, the build process fails with ESM-related errors.

Steps to Reproduce

1. Create or use an existing Bolt-CEP project
2. Install Tailwind CSS 4
3. Attempt to run the development server

Error Details

node_modules/esbuild/lib/main.js:1373:27: ERROR: [plugin: externalize-deps] Failed to resolve "@tailwindcss/vite". This package is ESM only but it was tried to load by require. See http://vitejs.dev/guide/troubleshooting.html#this-package-is-esm-only for more details.

Environment

• Bolt-CEP version: Using vite-cep-plugin v1.1.12
• Node.js version: v18.17.0
• Operating System: macOS (darwin 24.3.0)
• tailwindcss version: 4.1.2
• @tailwindcss/vite: 4.1.2

Notes

The error suggests that the build system is trying to use CommonJS require() to load an ESM-only package (@tailwindcss/vite). Tailwind CSS 4 has migrated to ESM-only modules, which is causing compatibility issues with Bolt-CEP's build system that likely expects CommonJS modules. According to the Vite troubleshooting guide, this indicates a module compatibility issue between ESM and CommonJS modules.

[igor-litvinovich]

Does Tailwind 3.4 work?

[jkl3848]

CEP doesn't support Tailwind 4 because of its chromium version. Might not be related to this issue specifically but you'll run into problems with it anyways.