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