Vercel deployment fails with "npm run build" exit code 1 error

The error "Command 'npm run build' exited with 1" is a generic Vercel deployment error that means your build process failed, but it doesn't tell you why. The exit code 1 just indicates failure. Here's how to troubleshoot and resolve this:

Step 1: Check Your Full Build Logs

The most important thing is to look at the complete build logs in Vercel, not just the final error message. The actual error will appear earlier in the logs:

1. Go to your Vercel dashboard
2. Click on the failed deployment
3. Scroll through the entire build log to find the actual error (usually appears before the "exited with 1" message)

Common errors you might find include:

• TypeScript type errors
• ESLint errors
• Missing environment variables
• Module not found errors
• API connection issues

Step 2: Common Sanity + Next.js Issues

If you're using Sanity with Next.js, here are specific issues to check:

Missing Environment Variables: Make sure you've added all required environment variables in your Vercel project settings:

• NEXT_PUBLIC_SANITY_PROJECT_ID
• NEXT_PUBLIC_SANITY_DATASET
• SANITY_API_TOKEN (if using authenticated requests)

TypeScript Errors: If you're getting type errors related to Sanity, ensure your @sanity/client and other Sanity packages are up to date. There was a known issue with TypeScript errors in @sanity/client that has been resolved in newer versions.

Module Not Found: If you see errors about missing @sanity/cli or other modules, this usually means your dependencies aren't properly listed in package.json. The Sanity community has documented this issue - make sure all Sanity packages are in dependencies (not devDependencies).

Step 3: Test Locally First

Before deploying, always run npm run build locally to catch errors:

npm run build

This will show you the exact same errors that Vercel encounters, but in your local environment where they're easier to debug.

Step 4: The CI= Override Won't Help

The CI= npm run build command you tried disables treating warnings as errors, but since you're getting a build failure (not warnings), this won't fix your issue. You need to find and fix the actual error in your logs.

Next Steps

Look through your complete Vercel build logs and identify the specific error message. If you share that specific error here, the community can provide more targeted help. The "exited with 1" message is just the symptom, not the root cause.