Skip to main content

Drift Guard

Available in: Professional, Business, Enterprise tiers

CI helper to catch breaking changes in generated outputs (schema/API drift).

What It Does​

Drift Guard generates no files

It compares two schema revisions, which prisma generate cannot supply, so it runs from the pzg-pro guard CLI or validateDrift(). There is no enableDriftGuard generator flag.

  • Compares generated output between --base and --head branches
  • Detects breaking changes in schemas, types, and APIs
  • Produces GitHub-formatted reports for PR comments

Prerequisites​

# PZG Pro license required (PZG_LICENSE_KEY)

Generate & Run​

pnpm exec pzg-pro guard --schema=./prisma/schema.prisma --base=origin/main --head=HEAD --format=github

Command Options​

  • --schema <path> – Path to your Prisma schema (defaults to ./prisma/schema.prisma).
  • --base <ref> – Git reference to compare from (defaults to origin/main).
  • --head <ref> – Git reference to compare to (defaults to HEAD).
  • --format <github|json|text> – Output format (defaults to github).
  • --json, --text, --github – Shortcut flags for --format.
  • --strict – Treat warnings as breaking changes.
  • --allowed-break <identifier> – Whitelist specific breaking change identifiers (repeatable).
  • --help – Show usage and exit.

Identifiers are <Model>.<field>:<change> for field-level changes and <Model>:<change> for model- and enum-level ones — for example User.email:field_removed, User.role:type_changed, or Session:model_removed.

The command runs entirely on the command line—no custom scripts required. Make sure you execute it inside a git repo (so the base ref can be resolved) and with a valid PZG Pro license available (PZG_LICENSE_KEY).

Under the hood the CLI loads the DMMF for the base and head schemas, runs validateDriftFromDMMF, and prints a GitHub-friendly report. A non-zero exit code indicates breaking changes.

Git history

Fetch the full history (fetch-depth: 0) before running the command in CI so the base ref’s schema can be read.

Programmatic API​

Prefer to orchestrate things yourself? Import validateDriftFromDMMF from prisma-zod-generator/lib/pro and feed it the base/head DMMF documents alongside your generator configuration. The CLI is thin sugar over that helper.

It resolves to { success, changes, output }, so you can inspect result.changes to build the identifiers used by --allowed-break.

GitHub Actions​

name: PZG Drift Guard
on: [pull_request]
jobs:
  guard:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 0
      - uses: pnpm/action-setup@v4
        with: { version: 9 }
      - run: pnpm i --frozen-lockfile
      - run: pnpm exec pzg-pro guard --base=origin/main --head=HEAD --format=github
        env:
          PZG_LICENSE_KEY: ${{ secrets.PZG_LICENSE_KEY }}

See Also​