Implement SSO as a Modular

Quick Start

Choose your authentication mode:

• Modular SSO: You manage users and sessions (covered here)
• Full-Stack Auth: Scalekit manages users and sessions (built-in SSO)

This skill covers Modular SSO for applications with existing user management.

Implementation Workflow

Copy this checklist and track progress:

Authentication Integration Progress:
- [ ] Step 1: Configure Modular Auth mode
- [ ] Step 2: Install and configure Scalekit SDK
- [ ] Step 3: Implement authorization URL generation
- [ ] Step 4: Handle IdP-initiated SSO (RECOMMENDED)
- [ ] Step 5: Process authentication callback
- [ ] Step 6: Validate tokens and extract user profile
- [ ] Step 7: Test SSO integration
- [ ] Step 8: Set up customer onboarding flow

Step 1: Configure Modular Auth Mode

Action: Configure environment for Modular SSO:

1. Navigate to Dashboard > Authentication > General
2. Under "Full-Stack Auth" section, click "Disable Full-Stack Auth"

Result: System ready for modular integration.

Step 2: Install and Configure SDK

Installation

Choose the SDK for the project's tech stack:

Node.js:

npm install @scalekit-sdk/node

Python:

pip install scalekit-sdk-python

Go:

go get github.com/scalekit-inc/scalekit-sdk-go

Java:

<dependency>
  <groupId>com.scalekit</groupId>
  <artifactId>scalekit-sdk-java</artifactId>
</dependency>

Environment Configuration

Add these credentials to .env file (fetch from Dashboard > Developers > Settings > API credentials):

SCALEKIT_ENVIRONMENT_URL=<environment-url>
SCALEKIT_CLIENT_ID=<client-id>
SCALEKIT_CLIENT_SECRET=<client-secret>

---

Step 3: Generate Authorization URL

Create authorization URL to redirect users to their identity provider.

SSO Connection Selectors (Priority Order)

Use ONE of these identifiers (evaluated in precedence order):

1. connectionId (highest) - Direct SSO connection reference
2. organizationId - Routes to organization's active SSO
3. loginHint - Extracts domain from email to find connection

Implementation Pattern

Node.js:

const scalekit = new ScalekitClient(
  process.env.SCALEKIT_ENVIRONMENT_URL,
  process.env.SCALEKIT_CLIENT_ID,
  process.env.SCALEKIT_CLIENT_SECRET
);

const options = {
  organizationId: 'org_15421144869927830',  // OR
  connectionId: 'conn_15696105471768821',   // OR
  loginHint: 'user@example.com'
};

const authUrl = scalekit.getAuthorizationUrl(
  'https://yourapp.com/auth/callback',
  options
);

// Redirect user to authUrl

Python:

from scalekit import ScalekitClient, AuthorizationUrlOptions

scalekit = ScalekitClient(
    os.getenv('SCALEKIT_ENVIRONMENT_URL'),
    os.getenv('SCALEKIT_CLIENT_ID'),
    os.getenv('SCALEKIT_CLIENT_SECRET')
)

options = AuthorizationUrlOptions()
options.organization_id = 'org_15421144869927830'

auth_url = scalekit.get_authorization_url(
    redirect_uri='https://yourapp.com/auth/callback',
    options=options
)

Direct URL (no SDK):

<SCALEKIT_ENVIRONMENT_URL>/oauth/authorize?
  response_type=code&
  client_id=<CLIENT_ID>&
  redirect_uri=<CALLBACK_URL>&
  scope=openid profile email&
  organization_id=<ORG_ID>

Step 4: Handle IdP-Initiated SSO

CRITICAL: Implement this to support users who start login from their identity provider portal.

Why This Matters

IdP-initiated SSO converts potentially insecure flows into secure SP-initiated flows, protecting against SAML assertion theft and replay attacks.

Configuration Required

1. Set initiate login endpoint: Dashboard > Authentication > Redirects
2. Configure endpoint: https://yourapp.com/login

Implementation

Node.js:

app.get('/login', async (req, res) => {
  const { idp_initiated_login, error, error_description } = req.query;

  if (error) {
    return res.status(400).json({ message: error_description });
  }

  if (idp_initiated_login) {
    // Decode JWT to extract connection details
    const claims = await scalekit.getIdpInitiatedLoginClaims(idp_initiated_login);

    const options = {
      connectionId: claims.connection_id,
      organizationId: claims.organization_id,
      loginHint: claims.login_hint,
      state: claims.relay_state
    };

    const authUrl = scalekit.getAuthorizationUrl(
      'https://yourapp.com/auth/callback',
      options
    );

    return res.redirect(authUrl);
  }

  // Handle normal login flow
});

Python:

@app.route('/login')
async def handle_login():
    idp_initiated_login = request.args.get('idp_initiated_login')
    error = request.args.get('error')

    if error:
        return {'error': request.args.get('error_description')}, 400

    if idp_initiated_login:
        claims = await scalekit.get_idp_initiated_login_claims(idp_initiated_login)

        options = AuthorizationUrlOptions()
        options.connection_id = claims.get('connection_id')
        options.organization_id = claims.get('organization_id')
        options.state = claims.get('relay_state')

        auth_url = scalekit.get_authorization_url(
            redirect_uri='https://yourapp.com/auth/callback',
            options=options
        )

        return redirect(auth_url)

---

Step 5: Process Authentication Callback

Handle the callback after successful IdP authentication.

Callback Endpoint Setup

1. Create endpoint: /auth/callback
2. Register in Dashboard > Authentication > Redirect URLs > Allowed Callback URLs

Implementation

Node.js:

app.get('/auth/callback', async (req, res) => {
  const { code, error, error_description } = req.query;

  if (error) {
    return res.status(400).json({ error: error_description });
  }

  try {
    // Exchange code for user profile and tokens
    const result = await scalekit.authenticateWithCode(
      code,
      'https://yourapp.com/auth/callback'
    );

    // Extract user information
    const userEmail = result.user.email;
    const userName = result.user.givenName + ' ' + result.user.familyName;
    const userId = result.user.id;

    // Create session for authenticated user
    req.session.user = {
      id: userId,
      email: userEmail,
      name: userName
    };

    res.redirect('/dashboard');
  } catch (err) {
    res.status(500).json({ error: 'Authentication failed' });
  }
});

Python:

@app.route('/auth/callback')
async def auth_callback():
    code = request.args.get('code')
    error = request.args.get('error')

    if error:
        return {'error': request.args.get('error_description')}, 400

    result = scalekit.authenticate_with_code(
        code,
        'https://yourapp.com/auth/callback'
    )

    # Create session
    session['user'] = {
        'id': result.user.id,
        'email': result.user.email,
        'name': f"{result.user.given_name} {result.user.family_name}"
    }

    return redirect('/dashboard')

---

Step 6: Validate Tokens

ALWAYS validate tokens before trusting claims.

Node.js:

// Validate ID token
const idTokenClaims = await scalekit.validateToken(result.idToken);

// Validate access token
const accessTokenClaims = await scalekit.validateToken(result.accessToken);

Python:

id_token_claims = scalekit.validate_token(result['id_token'])
access_token_claims = scalekit.validate_token(result['access_token'])

Token Structure

ID Token includes:

• email: User's email address
• given_name, family_name: User's name
• sub: Unique user identifier (format: connectionId;userId)
• oid: Organization ID
• amr: Authentication method (SSO connection ID)

Access Token includes:

• sub: User identifier
• exp: Expiration timestamp
• client_id: Your application client ID

Step 7: Test SSO Integration

Use the built-in IdP Simulator for comprehensive testing.

Test Organization Setup

Your environment includes pre-configured test organization with domains:

• @example.com
• @example.org

Testing Workflow

1. Find test organization: Dashboard > Organizations
2. Use test selector: Pass one of these in authorization URL:
   • Email with @example.com domain
   • Test organization's connection ID
   • Organization ID
3. Simulate SSO flow: IdP Simulator appears (mimics customer's IdP)
4. Complete authentication: Enter test credentials
5. Verify callback: Check user profile received correctly

Test Scenarios

Test ALL three scenarios:

1. SP-initiated SSO: User starts login from your app
2. IdP-initiated SSO: User starts from IdP portal
3. Domain-based routing: User enters email, auto-routes to IdP

---

Step 8: Customer Onboarding

Enable SSO for enterprise customers through self-service Admin Portal.

Quick Onboarding

Create organization: Dashboard > Organizations > New Organization

Generate portal link (Node.js):

const portalLink = await scalekit.organization.generatePortalLink(
  'org_32656XXXXXX0438'
);

// Share this link with customer's IT admin
console.log('Admin Portal:', portalLink.location);

Share link: Send to customer's IT administrator via email/Slack

Share setup guide: Include the Scalekit SSO setup guide — provider-specific steps for Okta, Azure AD, Google Workspace, and others.

Embedded Portal (Advanced)

Embed Admin Portal in your app for seamless experience:

// Backend: Generate portal link
const portalLink = await scalekit.organization.generatePortalLink(orgId);
res.json({ portalUrl: portalLink.location });

<!-- Frontend: Embed in iframe -->
<iframe
  src="${portalUrl}"
  width="100%"
  height="600"
  frameborder="0"
  allow="clipboard-write">
</iframe>

Advanced Patterns

Pre-Check SSO Availability

Prevent failed redirects by checking SSO configuration before redirecting:

Node.js:

const domain = email.split('@').toLowerCase(); [reddit](https://www.reddit.com/r/ClaudeAI/comments/1qb1024/ultimate_claude_skillmd_autobuilds_any_fullstack/)

const connections = await scalekit.connections.listConnectionsByDomain({
  domain
});

if (connections.length > 0) {
  // SSO available - redirect to IdP
  const authUrl = scalekit.getAuthorizationUrl(redirectUri, {
    domainHint: domain
  });
  return res.redirect(authUrl);
} else {
  // No SSO - show password login
  return showPasswordLogin();
}

Domain Verification

Enable seamless routing by verifying customer domains:

1. Customer verifies domain (e.g., @megacorp.org) in Admin Portal
2. Users sign in without organization selection
3. Scalekit auto-routes based on email domain

Session Management Best Practices

Set secure session configuration:

app.use(session({
  secret: process.env.SESSION_SECRET,
  resave: false,
  saveUninitialized: false,
  cookie: {
    secure: true,        // HTTPS only
    httpOnly: true,      // Prevent XSS
    maxAge: 86400000,    // 24 hours
    sameSite: 'lax'      // CSRF protection
  }
}));

Implement session refresh:

// Check token expiration
if (Date.now() / 1000 > accessTokenClaims.exp) {
  // Redirect to re-authentication
  return res.redirect('/login');
}

Integration with Existing Auth Systems

Auth0 Integration

Configure Scalekit as Custom Social Connection in Auth0:

1. Auth0 Dashboard > Authentication > Social > Create Connection
2. Use Scalekit OAuth2 endpoints
3. Map Scalekit user attributes to Auth0 profile

Firebase Integration

Add Scalekit as Custom Auth Provider:

1. Use Firebase Custom Token generation
2. Exchange Scalekit tokens for Firebase tokens
3. Maintain session with Firebase SDK

AWS Cognito Integration

Configure Scalekit as SAML Identity Provider:

1. Cognito User Pool > Identity Providers > SAML
2. Use Scalekit metadata URL
3. Map attributes to Cognito user attributes

Security Checklist

Before production deployment, verify:

• Environment variables stored securely (never in code)
• HTTPS enforced on all endpoints
• Tokens validated before trusting claims
• Session cookies use secure and httpOnly flags
• CSRF protection enabled
• Callback URLs registered in Scalekit dashboard
• Error messages don't expose sensitive information
• Rate limiting implemented on auth endpoints
• Logging configured (without exposing tokens)

Troubleshooting

"Invalid redirect_uri" Error

Cause: Callback URL not registered in dashboard Fix: Add URL to Dashboard > Authentication > Redirect URLs

"Organization not found" Error

Cause: Invalid organization ID or user doesn't belong to organization Fix: Verify organization ID and user's email domain

IdP-Initiated SSO Not Working

Cause: Initiate login URL not configured Fix: Set URL in Dashboard > Authentication > Redirects

Token Validation Fails

Cause: Token expired or invalid signature Fix: Check token expiration and environment URL configuration

Common Patterns

Multi-Tenant Architecture

// Determine organization from subdomain
const subdomain = req.hostname.split('.');
const organization = await getOrganizationBySubdomain(subdomain);

const authUrl = scalekit.getAuthorizationUrl(redirectUri, {
  organizationId: organization.scalekitOrgId
});

Step-Up Authentication

// Require re-authentication for sensitive operations
if (requiresStepUp && !session.recentAuth) {
  return res.redirect('/auth/step-up');
}

Logout Implementation

app.post('/logout', (req, res) => {
  req.session.destroy();
  res.redirect('/');
});

Reference

Scalekit Dashboard: https://app.scalekit.com

Connection Selector Precedence: connectionId > organizationId > loginHint

Token Expiration: ID tokens expire in 15 minutes, access tokens in 24 hours

Admin Portal Events: Listen for sso.enabled, sso.disabled, session.expired

Support: docs.scalekit.com

Implementation Notes

Always validate tokens: Never trust token claims without validation

Handle errors gracefully: Show user-friendly messages, log details internally

Test all scenarios: SP-initiated, IdP-initiated, and domain-based routing

Enable domain verification: Provides best user experience

Use progressive enhancement: Start with basic SSO, add advanced features iteratively

Monitor authentication flows: Track success rates and common failure points