types-gen

Development

Generate TypeScript types from Supabase database schema

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Generate Supabase Types

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/
Don't manually edit generated file
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.