Module not found: Can't resolve '@sanity/client' and 'groq' on Vercel deploy

This is a classic dependency installation issue! The errors show that Webpack can't find the @sanity/client and groq packages during your Vercel build, which means they're not installed in your project.

Here's how to fix it:

1. Install the missing packages locally:

npm install @sanity/client groq

or if you're using yarn:

yarn add @sanity/client groq

2. Verify your package.json:

After installing, make sure these packages appear in your package.json under "dependencies" (not "devDependencies"). They should look something like:

{
  "dependencies": {
    "@sanity/client": "^6.x.x",
    "groq": "^3.x.x"
  }
}

3. Commit and push:

git add package.json package-lock.json
git commit -m "Add missing Sanity dependencies"
git push

Why this happens:

This typically occurs when:

• You installed these packages globally instead of locally in your project
• You copied code from a tutorial but didn't install all dependencies
• Your node_modules folder exists locally (so it works on your machine) but the packages aren't listed in package.json, so Vercel doesn't know to install them

Note on versions:

If you're starting fresh, consider using the next-sanity package instead, which bundles the client and provides helpful Next.js-specific utilities. You can install it with:

npm install next-sanity @sanity/image-url

This should resolve your Vercel deployment errors. The build will work once Vercel can properly install all your dependencies from package.json!