supabase

Supabase

Supabase is an open source Firebase alternative. It provides a dedicated PostgreSQL database, packaged with Authentication, Realtime subscriptions, Storage, and Edge Functions.

When to Use

• Open-Source Firebase Alternative: Complete backend-as-a-service providing PostgreSQL, Auth, Realtime, Storage, and Edge Functions.
• Full Relational PostgreSQL Power: Direct access to real PostgreSQL with extensions (pgvector, PostGIS, pg_cron) and zero proprietary vendor lock-in.
• Row-Level Security (RLS) Authorization: Securing multi-tenant client queries directly at the database layer via SQL security policies.
• Real-Time Database Subscriptions: Subscribing to PostgreSQL insert, update, and delete events over WebSockets from client apps.

Quick Start

import { createClient } from "@supabase/supabase-js";

const supabase = createClient("https://xyz.supabase.co", "public-anon-key");

// Listen to changes
const subscription = supabase
  .channel("public:messages")
  .on(
    "postgres_changes",
    { event: "INSERT", schema: "public", table: "messages" },
    (payload) => {
      console.log("New message:", payload);
    },
  )
  .subscribe();

Core Concepts

PostgreSQL Row-Level Security (RLS)

Protects data at the database layer so clients can query the database directly from web/mobile apps safely:

-- Enable RLS on Table
ALTER TABLE documents ENABLE ROW LEVEL SECURITY;

-- Allow users to read and update only documents they own
CREATE POLICY "Users access own documents"
ON documents
FOR ALL
USING (auth.uid() = user_id)
WITH CHECK (auth.uid() = user_id);

Modern Supabase JavaScript / TypeScript Client

Type-safe database queries, authentication, and file storage:

import { createClient } from "@supabase/supabase-js";
import { Database } from "./types/supabase";

const supabase = createClient<Database>(
  process.env.SUPABASE_URL!,
  process.env.SUPABASE_ANON_KEY!,
);

// Query with automated RLS enforcement
const { data: projects, error } = await supabase
  .from("projects")
  .select("id, title, tasks(id, name, status)")
  .eq("status", "active")
  .order("created_at", { ascending: false });