Is there a post-migration hook?

[gcb]

Question

My application DB user must be granted access to newly created tables after a migration.

Right now we do it "manually" (add grant statements to migration)

Is there a way to automate this?

How to reproduce (optional)

Expected behavior (optional)

No response

Information about Prisma Schema, Client Queries and Environment (optional)

// Add your schema.prisma

// Add any relevant Prisma Client queries here

• OS:

• Database:

• Node.js version:

• Run prisma -v to see your Prisma version and paste it

[nurul3101]

Hi @gcb!

Currently you would need to manually grant the permissions. We have a related feature request here, which should make it easier to do this in future:

• Adding JS execution before and after migrations to allow for easier data migrations #19513

[Rick1330]

Automating Post-Migration Tasks (GRANTs, etc.)

I see you're looking for a way to automate database permissions after running prisma migrate. While Prisma doesn't currently have a built-in "post-migration hook" in the schema.prisma file, there are two established ways to handle this in a production workflow.

1. The "Custom Script" Wrapper (Recommended)

The most robust way is to wrap your migration command in a script (Bash or JS) that runs your GRANT statements immediately after the migration succeeds. This ensures the logic is versioned alongside your app.

Example migrate.sh:

#!/bin/bash
npx prisma migrate deploy
if [ $? -eq 0 ]; then
  echo "Migration successful, applying permissions..."
  # Use a raw SQL client to run your grants
  psql $DATABASE_URL -f ./scripts/apply_grants.sql
else
  echo "Migration failed, skipping grants."
  exit 1
fi

2. Using "Default Privileges" (Database Level)

If you are using PostgreSQL, you can solve this permanently at the database level without needing a hook. You can set Default Privileges so that any future tables created by your migration user are automatically granted to your application user.

Run this once in your DB:

ALTER DEFAULT PRIVILEGES IN SCHEMA public 
GRANT SELECT, INSERT, UPDATE, DELETE ON TABLES TO your_app_user;

Now, every time prisma migrate creates a table, your_app_user will already have access.

3. Prisma "Seed" as a Hook (Workaround)

Some teams use the prisma/seed.ts file for this, as it's often triggered after migrate dev. You can use $queryRaw to run the GRANT statements. However, be careful as seeding is primarily for data, not schema permissions.

Recommendation:
Option 2 (Default Privileges) is the "cleanest" for PostgreSQL as it requires zero code maintenance. If you need complex logic, Option 1 is the way to go.

If this helps automate your permissions, please consider marking it as the answer!

[gcb]

Option 2 is actually very sensible for my use-case. Embarrassed our team missed the 'alter default' when looking at the 'grant' manual pages :)

...to anyone going that route, don't forget SEQUENCES besides TABLES for most common setups.

[MukundaKatta]

No native hook yet. Two clean-ish options: chain it in your deploy script (prisma migrate deploy && psql -f grants.sql, and GRANT ... ON ALL TABLES is idempotent so safe to re-run), or push it into the DB via a Postgres EVENT TRIGGER on ddl_command_end that fires GRANT whenever a table is created. The event trigger is more robust since it works regardless of which tool runs the migration.