Supabase API Skill

JavaScript client and REST API reference.

Installation

npm install @supabase/supabase-js

Client Initialization

Browser Client

import { createClient } from '@supabase/supabase-js'

const supabase = createClient(
  'https://your-project.supabase.co',
  'your-anon-key'
)

With TypeScript Types

import { createClient } from '@supabase/supabase-js'
import { Database } from './database.types'

const supabase = createClient<Database>(
  process.env.NEXT_PUBLIC_SUPABASE_URL!,
  process.env.NEXT_PUBLIC_SUPABASE_ANON_KEY!
)

Server Client (Service Role)

const supabaseAdmin = createClient(
  process.env.SUPABASE_URL,
  process.env.SUPABASE_SERVICE_ROLE_KEY,
  {
    auth: {
      autoRefreshToken: false,
      persistSession: false
    }
  }
)

Custom Options

const supabase = createClient(url, key, {
  auth: {
    persistSession: true,
    autoRefreshToken: true,
    storage: localStorage,
    storageKey: 'supabase-auth'
  },
  global: {
    headers: { 'x-custom-header': 'value' }
  },
  db: {
    schema: 'public'
  },
  realtime: {
    params: {
      eventsPerSecond: 10
    }
  }
})

REST API Direct

API URL Format

https://<project-ref>.supabase.co/rest/v1/<table>

Headers

const headers = {
  'apikey': 'your-anon-key',
  'Authorization': 'Bearer your-anon-key',
  'Content-Type': 'application/json',
  'Prefer': 'return=representation'  // Return data after mutation
}

Select (GET)

# All rows
curl 'https://xxx.supabase.co/rest/v1/users' \
  -H "apikey: $SUPABASE_KEY" \
  -H "Authorization: Bearer $SUPABASE_KEY"

# Specific columns
curl 'https://xxx.supabase.co/rest/v1/users?select=id,name,email' \
  -H "apikey: $SUPABASE_KEY"

# With filter
curl 'https://xxx.supabase.co/rest/v1/users?status=eq.active' \
  -H "apikey: $SUPABASE_KEY"

# With pagination (query params)
curl 'https://xxx.supabase.co/rest/v1/users?limit=10&offset=0' \
  -H "apikey: $SUPABASE_KEY"

# With pagination (Range header - alternative)
curl 'https://xxx.supabase.co/rest/v1/users' \
  -H "apikey: $SUPABASE_KEY" \
  -H "Range: 0-9"

# With ordering
curl 'https://xxx.supabase.co/rest/v1/users?order=created_at.desc' \
  -H "apikey: $SUPABASE_KEY"

# Get count with results
curl 'https://xxx.supabase.co/rest/v1/users?select=*' \
  -H "apikey: $SUPABASE_KEY" \
  -H "Prefer: count=exact"

Insert (POST)

curl -X POST 'https://xxx.supabase.co/rest/v1/users' \
  -H "apikey: $SUPABASE_KEY" \
  -H "Authorization: Bearer $SUPABASE_KEY" \
  -H "Content-Type: application/json" \
  -H "Prefer: return=representation" \
  -d '{"name": "John", "email": "john@example.com"}'

Update (PATCH)

curl -X PATCH 'https://xxx.supabase.co/rest/v1/users?id=eq.123' \
  -H "apikey: $SUPABASE_KEY" \
  -H "Authorization: Bearer $SUPABASE_KEY" \
  -H "Content-Type: application/json" \
  -H "Prefer: return=representation" \
  -d '{"name": "John Doe"}'

Upsert (POST with Resolution)

curl -X POST 'https://xxx.supabase.co/rest/v1/users' \
  -H "apikey: $SUPABASE_KEY" \
  -H "Authorization: Bearer $SUPABASE_KEY" \
  -H "Content-Type: application/json" \
  -H "Prefer: return=representation,resolution=merge-duplicates" \
  -d '{"id": 123, "name": "John"}'

Delete (DELETE)

curl -X DELETE 'https://xxx.supabase.co/rest/v1/users?id=eq.123' \
  -H "apikey: $SUPABASE_KEY" \
  -H "Authorization: Bearer $SUPABASE_KEY"

Filter Operators (REST)

| Operator | Example | |----------|---------| | eq | ?status=eq.active | | neq | ?status=neq.deleted | | gt | ?age=gt.18 | | gte | ?age=gte.21 | | lt | ?price=lt.100 | | lte | ?price=lte.50 | | like | ?name=like.*John* | | ilike | ?name=ilike.*john* | | is | ?deleted_at=is.null | | in | ?status=in.(active,pending) | | cs | ?tags=cs.{sports,news} (contains) | | cd | ?tags=cd.{a,b,c} (contained by) | | or | ?or=(status.eq.active,status.eq.pending) | | and | ?and=(status.eq.active,verified.eq.true) |

JavaScript Client Quick Reference

Database Operations

// Select
const { data, error } = await supabase.from('table').select('*')

// Select with filter
const { data } = await supabase.from('table').select('*').eq('id', 1)

// Insert
const { data } = await supabase.from('table').insert({ col: 'value' }).select()

// Update
const { data } = await supabase.from('table').update({ col: 'new' }).eq('id', 1)

// Upsert
const { data } = await supabase.from('table').upsert({ id: 1, col: 'value' })

// Delete
const { error } = await supabase.from('table').delete().eq('id', 1)

// RPC (function call)
const { data } = await supabase.rpc('function_name', { param: 'value' })

Auth Operations

// Sign up
await supabase.auth.signUp({ email, password })

// Sign in
await supabase.auth.signInWithPassword({ email, password })

// Sign out
await supabase.auth.signOut()

// Get user
const { data: { user } } = await supabase.auth.getUser()

// Get session
const { data: { session } } = await supabase.auth.getSession()

// Auth state listener
supabase.auth.onAuthStateChange((event, session) => { })

Storage Operations

// Upload
await supabase.storage.from('bucket').upload('path', file)

// Download
const { data } = await supabase.storage.from('bucket').download('path')

// Get public URL
const { data } = supabase.storage.from('bucket').getPublicUrl('path')

// Get signed URL
const { data } = await supabase.storage.from('bucket').createSignedUrl('path', 3600)

// Delete
await supabase.storage.from('bucket').remove(['path'])

// List
const { data } = await supabase.storage.from('bucket').list('folder')

Realtime Operations

// Subscribe to database changes
const channel = supabase
  .channel('changes')
  .on('postgres_changes', { event: '*', schema: 'public', table: 'posts' }, callback)
  .subscribe()

// Broadcast
channel.send({ type: 'broadcast', event: 'message', payload: data })

// Presence
await channel.track({ user_id: '123' })
const state = channel.presenceState()

// Unsubscribe
await supabase.removeChannel(channel)

Edge Functions

const { data, error } = await supabase.functions.invoke('function-name', {
  body: { key: 'value' }
})

Error Handling

const { data, error } = await supabase.from('users').select('*')

if (error) {
  console.error('Error code:', error.code)
  console.error('Error message:', error.message)
  console.error('Error details:', error.details)
  console.error('Error hint:', error.hint)
  return
}

// data is safe to use
console.log(data)

Common Error Codes

| Code | Description | |------|-------------| | PGRST116 | No rows returned (single expected) | | PGRST301 | Multiple rows returned (single expected) | | 23505 | Unique constraint violation | | 23503 | Foreign key violation | | 42501 | RLS policy violation | | 42P01 | Table doesn't exist |

TypeScript Types

Generate Types

supabase gen types typescript --local > database.types.ts

Type Helpers

import { Database } from './database.types'

// Table row type
type User = Database['public']['Tables']['users']['Row']

// Insert type
type NewUser = Database['public']['Tables']['users']['Insert']

// Update type
type UpdateUser = Database['public']['Tables']['users']['Update']

// Query result type
import { QueryData } from '@supabase/supabase-js'

const usersQuery = supabase.from('users').select('id, name, posts(title)')
type UsersWithPosts = QueryData<typeof usersQuery>

References

• client-patterns.md - Common client patterns