Supabase Integration

Deploy Keplars as a Supabase Edge Function to send transactional and scheduled emails from your Supabase projects.

Overview

This integration provides a ready-to-use Supabase Edge Function that connects to Keplars email service. Built with Deno and TypeScript, it seamlessly integrates with your existing Supabase project.

GitHub Repository: github.com/KeplarsHQ/supabase-example

Features

Template-based emails - Use pre-designed templates with dynamic variables
Raw HTML/Text emails - Send custom HTML or plain text without templates
Scheduled emails - Schedule emails with timezone support
Instant delivery - 0-5 second delivery for critical emails
TypeScript - Full type safety with Deno
JWT verification - Optional authentication with Supabase Auth

Prerequisites

Before starting, you'll need:

A Supabase account (free tier works)
A Keplars account
Supabase CLI installed
Your Keplars API key (from dashboard)

Quick Start

1. Clone the Example

git clone https://github.com/KeplarsHQ/supabase-example.git
cd supabase-example

2. Configure API Key

Create a .env.local file in the supabase folder:

cd supabase
cp .env.local.example .env.local

Add your Keplars API key:

KEPLARS_API_KEY=kms_your_actual_api_key_here

3. Start Local Development

supabase start

The function will be available at:

http://127.0.0.1:54321/functions/v1/keplars-email-function

4. Test the Function

Send a test email:

curl --request POST 'http://127.0.0.1:54321/functions/v1/keplars-email-function' \
  --header 'Content-Type: application/json' \
  --data @test-text-email.json

Deployment

Deploy to Supabase Cloud

Link your Supabase project:

supabase link --project-ref your-project-ref

Set your API key as a secret:

supabase secrets set KEPLARS_API_KEY=kms_your_actual_api_key_here

Deploy the function:

supabase functions deploy keplars-email-function

Your function will be live at:

https://your-project-ref.supabase.co/functions/v1/keplars-email-function

Usage Examples

Template-Based Email

{
  "to": ["[email protected]"],
  "template_id": "your_template_id",
  "params": {
    "user_name": "John Doe",
    "verification_code": "123456"
  },
  "delivery_type": "instant"
}

Plain Text Email

{
  "to": ["[email protected]"],
  "subject": "Welcome!",
  "body": "Thanks for signing up. We're excited to have you.",
  "delivery_type": "instant"
}

HTML Email

{
  "to": ["[email protected]"],
  "subject": "Welcome!",
  "html": "<h1>Welcome!</h1><p>Thanks for signing up.</p>",
  "is_html": true,
  "delivery_type": "instant"
}

Scheduled Email

{
  "to": ["[email protected]"],
  "subject": "Weekly Newsletter",
  "html": "<h1>This Week's Updates</h1>",
  "scheduled_at": "2026-01-25T10:00:00",
  "timezone": "America/New_York"
}

Client Integration

JavaScript/TypeScript

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

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

// Send an email
const { data, error } = await supabase.functions.invoke('keplars-email-function', {
  body: {
    to: ['[email protected]'],
    template_id: 'your_template_id',
    params: {
      user_name: 'John',
      verification_code': '123456'
    },
    delivery_type: 'instant'
  }
})

if (error) {
  console.error('Failed to send email:', error)
} else {
  console.log('Email sent!', data)
}

React Example

import { useSupabaseClient } from '@supabase/auth-helpers-react'

function WelcomeEmail() {
  const supabase = useSupabaseClient()

  const sendWelcome = async (email: string, name: string) => {
    await supabase.functions.invoke('keplars-email-function', {
      body: {
        to: [email],
        template_id: 'your_welcome_template_id',
        params: { user_name: name }
      }
    })
  }

  return <button onClick={() => sendWelcome('[email protected]', 'Jane')}>
    Send Welcome Email
  </button>
}

Next.js API Route

// app/api/send-email/route.ts
import { createClient } from '@supabase/supabase-js'

export async function POST(request: Request) {
  const { email, name } = await request.json()

  const supabase = createClient(
    process.env.NEXT_PUBLIC_SUPABASE_URL!,
    process.env.SUPABASE_SERVICE_ROLE_KEY!
  )

  const { data, error } = await supabase.functions.invoke('keplars-email-function', {
    body: {
      to: [email],
      template_id: process.env.KEPLARS_TEMPLATE_ID,
      params: { user_name: name }
    }
  })

  return Response.json({ success: !error, data })
}

Security

Enable JWT Verification

For production, enable JWT verification in supabase/config.toml:

[functions.keplars-email-function]
verify_jwt = true

This requires all requests to include a valid Supabase auth token.

Environment Variables

Keep your .env.local file secure (never commit it)
Use supabase secrets for production API keys
Use different API keys for development and production

API Reference

Request Fields

Required:

to - Array of email addresses
For template emails: template_id
For raw emails: subject + either body or html

Optional:

params - Template variables (template emails only)
is_html - Set to true for HTML content
delivery_type - Either "instant" or "queue"
scheduled_at - ISO 8601 timestamp for scheduled emails
timezone - IANA timezone (e.g., "America/New_York")
from - Sender email
fromName - Sender name

Response Format

Success:

{
  "id": "msg_...",
  "object": "email",
  "status": "queued",
  "from": "[email protected]",
  "to": ["[email protected]"],
  "created_at": "2026-01-22T22:14:04.470Z"
}

Error:

{
  "success": false,
  "error": "Error message",
  "code": "ERROR_CODE"
}

Troubleshooting

Function not found

Make sure you've deployed the function:

supabase functions deploy keplars-email-function

API key not configured

Ensure your API key is set:

# Local
echo "KEPLARS_API_KEY=kms_..." >> supabase/.env.local

# Production
supabase secrets set KEPLARS_API_KEY=kms_...

Email not arriving

Check your spam folder
Verify template exists in Keplars dashboard
Ensure email provider is connected in Keplars
Check Supabase function logs: supabase functions log keplars-email-function

Resources

Support

Need help? Reach out:

Email: [email protected]
Discord: Join our community
GitHub Issues: Report a bug

Supabase Integration

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