Volcano/ Docs
Volcano DocumentationAuthentication

Email Verification

Require users to confirm their email addresses before signing in.

Require users to confirm their email addresses before signing in.

Overview

Email verification adds a security layer by ensuring users own the email addresses they register with:

1. User signs up → Receives confirmation email
2. User clicks link → Email confirmed
3. User can now sign in

Use cases:

  • Prevent fake account creation
  • Verify email ownership
  • Enable password reset functionality
  • Reduce spam and abuse
  • Compliance requirements

Configuration

Enable Email Verification

{
  "require_email_confirmation": true,
  "email_confirmation_timeout": 86400
}

Settings:

  • require_email_confirmation - Enable/disable (default: false)
  • email_confirmation_timeout - Token expiry in seconds (default: 86400 = 24 hours)
  • require_email_confirmation=true requires email_enabled=true

Configure Email Sending

Email verification requires SMTP configuration:

{
  "email_enabled": true,
  "email_from_address": "noreply@myapp.com",
  "email_from_name": "My App",
  "smtp_host": "smtp.sendgrid.net",
  "smtp_port": 587,
  "smtp_username": "apikey",
  "smtp_password": "SG.your-api-key",
  "smtp_use_tls": true
}

If require_email_confirmation is enabled, API updates that set email_enabled to false are rejected until require_email_confirmation is disabled first.

SMTP Providers:

  • SendGrid: smtp.sendgrid.net:587
  • AWS SES: email-smtp.{region}.amazonaws.com:587
  • Mailgun: smtp.mailgun.org:587
  • Gmail: smtp.gmail.com:587 (requires app password)
  • Custom: Any SMTP server

Email Confirmation Flow

1. User Signs Up

POST /auth/signup
Authorization: Bearer <anon_key>
Content-Type: application/json

Request:

{
  "email": "user@example.com",
  "password": "password123"
}

Response:

{
  "access_token": "...",
  "refresh_token": "...",
  "user": {
    "id": "uuid",
    "email": "user@example.com",
    "email_confirmed": false
  }
}

What happens:

  • User created with email_confirmed: false
  • Confirmation token generated and stored
  • Confirmation email sent to user

2. Confirmation Email Sent

Email contains:

  • Confirmation link with token
  • Link expires after configured timeout
  • Clear call-to-action button

Example link:

https://yourapp.com/confirm?token=abc123xyz789

3. User Confirms Email

POST /auth/confirm
Authorization: Bearer <anon_key>
Content-Type: application/json

Request:

{
  "token": "abc123xyz789"
}

Response:

{
  "message": "Email confirmed successfully"
}

Also possible:

{
  "message": "Email already confirmed"
}

What happens:

  • Token validated (project-scoped + expiration checked)
  • User marked as email_confirmed: true
  • Token cleared (one-time use)

4. User Can Sign In

POST /auth/signin
Authorization: Bearer <anon_key>

Before confirmation:

{
  "error": "email confirmation required - please check your email for confirmation link"
}

After confirmation:

{
  "access_token": "...",
  "refresh_token": "...",
  "user": {
    "email_confirmed": true
  }
}

Resend Confirmation

If user didn't receive the email:

POST /auth/resend-confirmation
Authorization: Bearer <anon_key>
Content-Type: application/json

Request:

{
  "email": "user@example.com"
}

Response:

{
  "message": "If the email exists and is unconfirmed, a confirmation link has been sent"
}

Security:

  • Generic response (doesn't reveal if email exists)
  • Doesn't reveal if already confirmed
  • Rate limited like signup
  • If user exists and is unconfirmed, resend rotates token (old link becomes invalid)
  • If user doesn't exist or is already confirmed, no email is sent

Frontend Integration

// Sign up
const { user, session } = await volcano.auth.signUp({
  email: 'user@example.com',
  password: 'password123'
});

if (!user.email_confirmed) {
  showMessage('Please check your email for confirmation link');
}

// User clicks link from email → opens /confirm?token=abc123

// Confirm email
await volcano.auth.confirmEmail(urlParams.get('token'));
showMessage('Email confirmed! You can now sign in.');

// Sign in
const { user, session } = await volcano.auth.signIn({
  email: 'user@example.com',
  password: 'password123'
});
// ✓ Success - email is confirmed

// Resend confirmation (if needed)
await volcano.auth.resendConfirmation('user@example.com');
showMessage('Confirmation email resent');

Email Customization

Custom Subject Lines

{
  "email_confirmation_subject": "Welcome! Confirm your email",
  "email_password_reset_subject": "Reset your password for MyApp",
  "email_password_changed_subject": "Security alert: Password changed"
}

Custom Email Templates

Create custom templates per project (optional - overrides defaults):

POST /projects/{projectId}/email-templates
Authorization: Bearer <platform_token>
Content-Type: application/json

Request:

{
  "template_type": "confirmation",
  "subject": "Welcome to MyApp!",
  "html_body": "...",
  "text_body": "..."
}

Template variables:

  • {{.Email}} - User's email address
  • {{.ConfirmationURL}} - Confirmation link with token
  • {{.ProjectName}} - Your project name
  • {{.AppName}} - Your app name

Security

Token Security

Cryptographically secure:

  • Generated using crypto/rand
  • 64 characters (32 bytes hex-encoded)
  • One-time use (cleared after confirmation)
  • Time-limited expiration

Project-scoped:

  • Tokens only work within their project
  • Cannot use Project A token in Project B

Email Enumeration Prevention

All responses are generic:

  • Resend confirmation: Same message whether email exists or not
  • Already confirmed: Same message as not found
  • Prevents attackers from discovering registered emails

Rate Limiting

Applies to:

  • Signup (includes confirmation email sending)
  • Resend confirmation (uses signup rate limit)

Configuration Examples

SendGrid

curl -X PUT https://api.volcano.dev/projects/PROJECT_ID/auth/config \
  -H "Authorization: Bearer TOKEN" \
  -d '{
    "email_enabled": true,
    "email_from_address": "noreply@myapp.com",
    "email_from_name": "My App",
    "smtp_host": "smtp.sendgrid.net",
    "smtp_port": 587,
    "smtp_username": "apikey",
    "smtp_password": "SG.your-sendgrid-api-key",
    "smtp_use_tls": true,
    "require_email_confirmation": true
  }'

AWS SES

curl -X PUT https://api.volcano.dev/projects/PROJECT_ID/auth/config \
  -H "Authorization: Bearer TOKEN" \
  -d '{
    "email_enabled": true,
    "email_from_address": "noreply@myapp.com",
    "smtp_host": "email-smtp.us-east-1.amazonaws.com",
    "smtp_port": 587,
    "smtp_username": "AKIAIOSFODNN7EXAMPLE",
    "smtp_password": "your-smtp-password",
    "smtp_use_tls": true,
    "require_email_confirmation": true
  }'

Mailgun

curl -X PUT https://api.volcano.dev/projects/PROJECT_ID/auth/config \
  -d '{
    "email_enabled": true,
    "email_from_address": "noreply@mg.myapp.com",
    "smtp_host": "smtp.mailgun.org",
    "smtp_port": 587,
    "smtp_username": "postmaster@mg.myapp.com",
    "smtp_password": "your-mailgun-smtp-password",
    "smtp_use_tls": true,
    "require_email_confirmation": true
  }'

Behavior

When Email Verification Enabled

Signup:

  • User created with email_confirmed: false
  • Confirmation email sent automatically
  • Returns access token (can use app but can't sign in again)

Signin:

  • Blocked if email not confirmed
  • Error: "email confirmation required"
  • User must confirm email first

Resend:

  • Generates new token
  • Sends new email
  • Previous token becomes invalid

When Email Verification Disabled

Signup:

  • User created with email_confirmed: false (or true, doesn't matter)
  • No confirmation email sent
  • Can sign in immediately

Signin:

  • Works regardless of email_confirmed status
  • No blocking

Token Expiration

Default: 24 hours (86400 seconds)

Configurable:

{"email_confirmation_timeout": 3600}  // 1 hour
{"email_confirmation_timeout": 604800}  // 7 days

After expiration:

  • Token becomes invalid
  • User must request new confirmation email
  • Use resend-confirmation endpoint

Troubleshooting

Emails Not Sending

Check configuration:

# Get current config
curl https://api.volcano.dev/projects/PROJECT_ID/auth/config \
  -H "Authorization: Bearer TOKEN"

# Verify:
# - email_enabled: true
# - smtp_host, smtp_port set correctly
# - smtp_username, smtp_password are correct
# - email_from_address is valid

Test SMTP connection:

  • Use telnet smtp.host.com 587 to verify connectivity
  • Check SMTP credentials with provider
  • Verify from address is authorized (SPF/DKIM)

Emails Going to Spam

Improve deliverability:

  • Set up SPF records for your domain
  • Configure DKIM signing
  • Use verified sender address
  • Keep email content simple (default templates optimized)
  • Monitor bounce rates

User Can't Find Email

Common issues:

  • Email in spam folder
  • Wrong email address entered
  • Email service delay
  • Token expired (user waited too long)

Solution:

  • Use resend-confirmation endpoint
  • Check spam folder
  • Verify email address is correct

See Also

Configuring Authentication Methods Per Project

Control which authentication methods each project enables — email/password, OAuth providers, and anonymous — to match your use case.

Managed Hosted Auth Pages

Managed hosted auth pages let you serve customizable authentication pages directly from Volcano for each project.

On this page

OverviewConfigurationEnable Email VerificationConfigure Email SendingEmail Confirmation Flow1. User Signs Up2. Confirmation Email Sent3. User Confirms Email4. User Can Sign InResend ConfirmationFrontend IntegrationEmail CustomizationCustom Subject LinesCustom Email TemplatesSecurityToken SecurityEmail Enumeration PreventionRate LimitingConfiguration ExamplesSendGridAWS SESMailgunBehaviorWhen Email Verification EnabledWhen Email Verification DisabledToken ExpirationTroubleshootingEmails Not SendingEmails Going to SpamUser Can't Find EmailSee Also