/types-gen

Generate TypeScript types from the Supabase database schema.

Command

Run the following command to generate types:

npx supabase gen types typescript --project-id YOUR_PROJECT_ID > lib/database.types.ts

Or if using local Supabase:

npx supabase gen types typescript --local > lib/database.types.ts

Setup for Auto-Generation

1. Add to package.json

{
  "scripts": {
    "gen-types": "npx supabase gen types typescript --project-id $SUPABASE_PROJECT_ID > lib/database.types.ts",
    "gen-types:local": "npx supabase gen types typescript --local > lib/database.types.ts"
  }
}

2. Usage in Code

import type { Database } from '@/lib/database.types'

// Get table type
type User = Database['public']['Tables']['users']['Row']
type UserInsert = Database['public']['Tables']['users']['Insert']
type UserUpdate = Database['public']['Tables']['users']['Update']

// Use with Supabase client
const supabase = createClient<Database>(url, key)

// Type-safe queries
const { data } = await supabase
  .from('users')
  .select('*')
  .single()  // data is typed as User

// Type-safe inserts
const { data } = await supabase
  .from('users')
  .insert({
    email: 'user@example.com',
    name: 'John Doe'
  })  // TypeScript validates the shape

3. Create Utility Types

// lib/database.helpers.ts
import type { Database } from './database.types'

// Extract table types
export type Tables<T extends keyof Database['public']['Tables']> =
  Database['public']['Tables'][T]['Row']

export type Enums<T extends keyof Database['public']['Enums']> =
  Database['public']['Enums'][T]

// Usage
import type { Tables } from '@/lib/database.helpers'
type User = Tables<'users'>
type Post = Tables<'posts'>

4. When to Regenerate

Run npm run gen-types after:

• Creating new tables
• Adding/removing columns
• Changing column types
• Modifying RLS policies
• Adding enums

5. Best Practices

•  Commit generated types to git
•  Run after schema changes
•  Use in all Supabase queries
•  Create helper types for common patterns
•  Keep types file in lib/ or types/
• L Don't manually edit generated file
• L Don't use any instead of generated types

6. Integration with Pre-commit Hook

# .husky/pre-commit
#!/bin/sh
npm run gen-types
git add lib/database.types.ts

Troubleshooting

Issue: supabase command not found

npm install -g supabase

Issue: Missing project ID

# Find your project ID in Supabase dashboard
# Or set in .env
SUPABASE_PROJECT_ID=your-project-id

Issue: Types not updating

# Clear cache and regenerate
rm lib/database.types.ts
npm run gen-types

Generate and use TypeScript types to catch database-related bugs at compile time instead of runtime.