Windsurf integration

NPM Conflicting Peer Dependencies in Windsurf Project

Running npm install in your Windsurf-generated project fails with ERESOLVE peer dependency conflict errors. Cascade added packages that require incompatible versions of shared dependencies, and npm cannot resolve a valid dependency tree.

This is one of the most frustrating issues in Node.js projects because it blocks all progress — you can't install any packages until the conflict is resolved. The error messages are dense and confusing, listing multiple packages and version ranges that seem impossible to untangle.

The problem typically appears after Cascade adds a new package, when upgrading an existing package, or when combining packages that Cascade recommended in different sessions without checking compatibility.

Error Messages You Might See

npm ERR! ERESOLVE unable to resolve dependency tree npm ERR! Could not resolve dependency: peer react@"^17.0.0" from package@1.0.0 npm ERR! Conflicting peer dependency: react@17.0.2 npm ERR! Fix the upstream dependency conflict npm WARN overriding peer dependency
npm ERR! ERESOLVE unable to resolve dependency treenpm ERR! Could not resolve dependency: peer react@"^17.0.0" from package@1.0.0npm ERR! Conflicting peer dependency: react@17.0.2npm ERR! Fix the upstream dependency conflictnpm WARN overriding peer dependency

Common Causes

  • React version conflicts — One package requires React 17 while another requires React 18, or a package needs React as a peer dependency but the project uses a different version
  • Multiple UI library versions — Cascade installed both an old and new version of the same UI library (e.g., Material UI v4 and v5)
  • Outdated packages — Cascade recommended packages with peer dependencies pinned to old versions that conflict with your current stack
  • TypeScript version mismatch — Different packages require different TypeScript versions as peer dependencies
  • Using --legacy-peer-deps as a band-aid — Previous installs used --legacy-peer-deps to hide conflicts, creating an unstable node_modules that eventually breaks

How to Fix It

  1. Read the error carefully — npm's ERESOLVE error tells you exactly which packages conflict and what versions they need. Identify the root conflicting dependency
  2. Check if packages have compatible versions — Often updating one conflicting package to its latest version resolves the peer dependency conflict
  3. Use npm ls to inspect the tree — Run npm ls [package-name] to see which versions are installed and which packages depend on them
  4. Remove and reinstall — Delete node_modules and package-lock.json, then run npm install fresh. This often resolves phantom conflicts from corrupted lock files
  5. Use overrides for stubborn conflicts — Add an "overrides" field in package.json to force a specific version of the conflicting peer dependency
  6. Avoid --force and --legacy-peer-deps — These flags hide the problem but can cause runtime errors. Only use them as a last resort after understanding the implications

Real developers can help you.

Jared Hasson Jared Hasson Full time lead founding dev at a cyber security saas startup, with 10 yoe and a bachelor's in CS. Building & debugging software products is what I've spent my time on for forever Daniel Vázquez Daniel Vázquez Software Engineer with over 10 years of experience on Startups, Government, big tech industry & consulting. rayush33 rayush33 JavaScript (React.js, React Native, Node.js) Developer with demonstrated industry experience of 4+ years, actively looking for opportunities to hone my skills as well as help small-scale business owners with solutions to technical problems legrab legrab I'll fill this later Milan Surelia Milan Surelia Milan Surelia is a Mobile App Developer with 5+ years of experience crafting scalable, cross-platform apps at 7Span and Meticha. At 7Span, he engineers feature-rich Flutter apps with smooth performance and modern UI. As the Co-Founder of Meticha, he builds open-source tools and developer-focused products that solve real-world problems. Expertise: 💡 Developing cross-platform apps using Flutter, Dart, and Jetpack Compose for Android, iOS, and Web. 🖋️ Sharing insights through technical writing, blogging, and open-source contributions. 🤝 Collaborating closely with designers, PMs, and developers to build seamless mobile experiences. Notable Achievements: 🎯 Revamped the Vepaar app into Vepaar Store & CRM with a 2x performance boost and smoother UX. 🚀 Launched Compose101 — a Jetpack Compose starter kit to speed up Android development. 🌟 Open source contributions on Github & StackOverflow for Flutter & Dart 🎖️ Worked on improving app performance and user experience with smart solutions. Milan is always happy to connect, work on new ideas, and explore the latest in technology. Rudra Bhikadiya Rudra Bhikadiya I build and fix web apps across Next.js, Node.js, and DBs. Comfortable jumping into messy code, broken APIs, and mysterious bugs. If your project works in theory but not in reality, I help close that gap. Tejas Chokhawala Tejas Chokhawala Full-stack engineer with 5 years experience building production web apps using React, Next.js and TypeScript. Focused on performance, clean architecture and shipping fast. Experienced with Supabase/Postgres backends, Stripe billing, and building AI-assisted developer tools. Richard McSorley Richard McSorley Full-Stack Software Engineer with 8+ years building high-performance applications for enterprise clients. Shipped production systems at Walmart (4,000+ stores), Cigna (20M+ users), and Arkansas Blue Cross. 5 patents in retail/supply chain tech. Currently focused on AI integrations, automation tools, and TypeScript-first architectures. Jen Jacobsen Jen Jacobsen I’m a Full-Stack Developer with over 10 years of experience building modern web and mobile applications. I enjoy working across the full product lifecycle — turning ideas into real, well-built products that are intuitive for users and scalable for businesses. I particularly enjoy building mobile apps, modern web platforms, and solving complex technical problems in a way that keeps systems clean, reliable, and easy to maintain. Mehdi Ben Haddou Mehdi Ben Haddou - Founder of Chessigma (1M+ users) & many small projects - ex Founding Engineer @Uplane (YC F25) - ex Software Engineer @Amazon and @Booking.com

You don't need to be technical. Just describe what's wrong and a verified developer will handle the rest.

Get Help

Frequently Asked Questions

Is it safe to use --legacy-peer-deps?

It's a temporary workaround, not a fix. --legacy-peer-deps tells npm to ignore peer dependency conflicts, which may cause runtime errors if the packages are truly incompatible. Use it only to unblock yourself while you find a proper resolution.

What are peer dependencies and why do they cause conflicts?

Peer dependencies are packages that a library expects YOU to install (like React for a React component library). Conflicts happen when two libraries expect different versions of the same peer dependency. Only one version can exist in your project.

Related Windsurf Issues

Can't fix it yourself?
Real developers can help.

You don't need to be technical. Just describe what's wrong and a verified developer will handle the rest.

Get Help