EasyApp

Develop Supabase Backend Service

Learn how to develop Supabase backend service in the EasyAppSupabase project

Local Development Environment Setup

Start Local Supabase Service

Run in the EasyAppSupabase directory:

cd EasyAppSupabase
npx supabase start

Before downloading Docker images, we recommend installing Docker Desktop

The first run will download Docker images, which may take a few minutes.

Check Service Status

npx supabase status

swiftui_supabase-keys

This will display URLs and keys for all services, including:

  • API URL: http://localhost:54321
  • Database URL: postgresql://postgres:[PASSWORD]@localhost:54322/postgres
  • Secret key: For client requests

Then add the API URL and Secret key to the EasyAppSwiftUI/Constants/Constants.swift file.

enum Supabase {
  /// Development supabase url
  #if DEBUG
    static let url = "http://localhost:54321"
    /// The anon key
    static let key ="your_anon_key_here"
  #else
}

Developing Edge Functions

The SupabaseEdgeFunction project already has built-in all the Edge Functions required for the easyapp template. You can refer to these functions to create your own functions.

Generate Function Using CLI

npx supabase functions new my-function

This creates a basic template in the supabase/functions/my-function/ directory:

// supabase/functions/my-function/index.ts
import "jsr:@supabase/functions-js/edge-runtime.d.ts"

Deno.serve(async (req) => {
  const { name } = await req.json()
  const data = {
    message: `Hello ${name}!`,
  }

  return new Response(
    JSON.stringify(data),
    { headers: { "Content-Type": "application/json" } },
  )
})

Configure Dependencies

Create a deno.json file to manage dependencies:

{
  "imports": {
    "@supabase/supabase-js": "jsr:@supabase/supabase-js@^2.50.2",
    "@openai/openai": "jsr:@openai/openai@^5.8.1"
  }
}

Access Environment Variables

In your function, you can access environment variables through Deno.env.get():

// Get environment variables
const apiKey = Deno.env.get("OPENAI_API_KEY")
const customVar = Deno.env.get("YOUR_CUSTOM_VARIABLE")

Using Shared Tools

EasyAppSupabase provides pre-configured shared tools that can be used directly in your functions:

Using Supabase Client

import {
  supabaseServiceRoleKey,
  supabaseUrl,
} from "../_shared/SupabaseClient.ts";

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

Deno.serve(async (req) => {
  const supabaseClient = createClient(
    supabaseUrl,
    supabaseServiceRoleKey,
  );
  
  // Get user authentication info
  const authHeader = req.headers.get("Authorization");
  if (!authHeader) {
    return new Response("Unauthorized", { status: 401 });
  }
  
  const token = authHeader.replace("Bearer ", "");
  const { data: user } = await supabaseClient.auth.getUser(token);
  
  if (!user) {
    return new Response("Invalid token", { status: 401 });
  }
  
  // Database operations
  const { data, error } = await supabaseClient
    .from('your_table')
    .select('*')
    .eq('user_id', user.user.id);
  
  return new Response(JSON.stringify(data), {
    headers: { "Content-Type": "application/json" }
  });
});

Using OpenAI Client

import { openAIClient } from "../_shared/OpenAIClient.ts";
import { createClient } from "@supabase/supabase-js";

Deno.serve(async (req) => {
  const { prompt } = await req.json();
  
  const response = await openAIClient.chat.completions.create({
    model: "gpt-3.5-turbo",
    messages: [{ role: "user", content: prompt }],
  });
  
  return new Response(JSON.stringify({
    result: response.choices[0].message.content
  }), {
    headers: { "Content-Type": "application/json" }
  });
});

Local Testing

Configure Environment Variables

Configure your environment variables in the supabase/.env.local file:

# supabase/.env.local
# OpenAI
OPENAI_API_KEY=your_openai_api_key_here


# Supabase

# supabase local development uses LOCAL_DEV prefix
LOCAL_DEV_SUPABASE_URL=http://127.0.0.1:54321
LOCAL_DEV_SUPABASE_SERVICE_ROLE_KEY=your_supabase_service_role_key_here

# Other environment variables

LOCAL_DEV_SUPABASE_SERVICE_ROLE_KEY can be obtained from here SERVICE_ROLE_KEY

Configure Database Tables

  1. Create a new migration file:
npx supabase migration new your_migration_name

  1. Edit the generated SQL file in supabase/migrations/

  2. Apply migration:

npx supabase db push

Start Function Service

# Start specific function and load environment variables
npx supabase functions serve my-function --env-file ./supabase/.env.local

# Start all functions and load environment variables
npx supabase functions serve --env-file ./supabase/.env.local

The function will run at http://localhost:54321/functions/v1/my-function.

Test Function

Use curl to test your function:

# Get local anon key
npx supabase status

# Test function
curl -i --location --request POST 'http://localhost:54321/functions/v1/my-function' \
  --header 'Authorization: Bearer YOUR_LOCAL_ANON_KEY' \
  --header 'Content-Type: application/json' \
  --data '{"name":"World"}'

View Logs

Function logs will display in real-time in the terminal to help you debug issues.

Best Practices

Security

  • Always verify user identity (unless it's a public Webhook)
  • Use environment variables to store sensitive information (API keys, database connection strings, etc.)
  • Implement proper error handling

Troubleshooting

Common Issues

Function won't start

  • Make sure Docker is running
  • Run supabase stop then supabase start to restart services

Port conflicts

  • Check supabase status to see occupied ports
  • Stop other Supabase instances

Deployment fails

  • Check function code syntax
  • Ensure all dependencies are properly configured
  • Verify environment variable settings

Environment variables can't be read

  • Ensure .env.local file format is correct (KEY=value)
  • Use --env-file parameter when starting functions
  • Check if environment variable names are spelled correctly

View Logs

# View function logs
npx supabase functions logs my-function

# View logs in real-time
npx supabase functions logs my-function --follow

Through this guide, you should be able to successfully create, test, and deploy Supabase Cloud Functions in your EasyAppSupabase project.

To learn more about Supabase Cloud Functions, please refer to the official Supabase Cloud Functions documentation

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