Why is prisma being installed?

[bestickley]

Why is prisma being install in my pnpm monorepo? I have drizzle-orm installed in root but no reference to prisma. See:

pnpm why prisma
prisma@7.4.2
├─┬ @prisma/client@7.4.2
│ └─┬ drizzle-orm@0.44.7
│   └── @relevan/monorepo@0.1.0 (devDependencies)
└── drizzle-orm@0.44.7 [deduped]

Found 1 version of prisma

I see prisma is listed as optional peer dependency, but that shouldn't make it be installed, right?

[AndriiSherman]

it should not install peer deps, unless pnpm is doing it by default
but we will remove prisma from peerDeps as well so there shouldn't by any issues

[Felipeness]

pnpm is being overly helpful here. Since v8, auto-install-peers=true is the default, and it doesn't distinguish between required and optional peer deps — so it pulls in @prisma/client because drizzle lists it as an optional peer (along with every other driver it supports).

Quickest fix — add to your .npmrc:

auto-install-peers=true
optional-peers=false

Or if you want something more surgical, tell pnpm to ignore that specific peer in package.json:

"pnpm": {
  "peerDependencyRules": {
    "ignoreMissing": ["@prisma/client"]
  }
}

Run pnpm install again and prisma should disappear. You can double-check with pnpm why @prisma/client to confirm drizzle was the one dragging it in.

[bestickley]

Are you sure? From PNPM docs

autoInstallPeers - When true, any missing non-optional peer dependencies are automatically installed.

[bestickley]

There is also ignoreOptionalDependencies but I have to write out every optional dependency I want to ignore which is annoying.