npm ERR! ERESOLVE unable to resolve dependency tree

What it means

Two of your add-on packages want different versions of the same thing (often React), and npm refuses to guess which one wins.

How to fix it: paste this prompt into your AI builder

npm install fails with ERESOLVE. Read which package requires which peer version. Fix it by upgrading the conflicting package to a version that supports my current React/Next version (or picking a maintained alternative), and update package.json accordingly. Use --legacy-peer-deps only as a last resort and tell me if you do. Don't upgrade unrelated packages or change app code beyond what the new version needs.

If the AI can't fix it: manual steps

1. Look for 'Could not resolve dependency: peer X from Y'; Y is the package that is out of date.

Where this happens

Seen in these AI app builders and editors:

Sources

• https://stackoverflow.com/questions/64573177/unable-to-resolve-dependency-tree-error-when-installing-npm-packages
• https://thinktank.ottomator.ai/t/cloudflare-pages-error-failed-to-start-application/3335

Related dependencies errors

• sh: vite: command not found (exit code 127)#27 · dependencies
• Node.js version mismatch (Unsupported engine / requires Node >= 18)#56 · dependencies
• npm ERR! enoent Could not read package.json#57 · dependencies
• Error: listen EADDRINUSE: address already in use :::3000#60 · dependencies