Payment Integration

When to Use

• Payment gateway integration (checkout, processing)
• Subscription management (trials, upgrades, billing)
• Webhook handling (payment notifications)
• QR code payments (VietQR, NAPAS)
• Usage-based billing (metering, credits)
• Automated benefit delivery (licenses, GitHub access, Discord roles)
• Customer portals (self-service management)
• Bank transfer automation (Vietnamese banks)
• Product catalogs with pricing

Platform Selection

• Vietnamese market (VND currency)
• Bank transfer automation
• VietQR/NAPAS payments
• Local payment methods
• Direct bank account monitoring

• Global SaaS products
• Subscription management
• Usage-based billing
• Automated benefits (GitHub, Discord, licenses)
• Merchant of Record (tax compliance)
• Digital product sales

Quick Reference

SePay Integration

• Overview & Auth:

  references/sepay/overview.md

  - Platform capabilities, API/OAuth2 auth, supported banks
• API Reference:

  references/sepay/api.md

  - Endpoints, transactions, bank accounts, virtual accounts
• Webhooks:

  references/sepay/webhooks.md

  - Setup, payload structure, verification, retry logic
• SDK Usage:

  references/sepay/sdk.md

  - Node.js, PHP, Laravel implementations
• QR Codes:

  references/sepay/qr-codes.md

  - VietQR generation, templates, integration
• Best Practices:

  references/sepay/best-practices.md

  - Security, patterns, monitoring

Polar Integration

• Overview & Auth:

  references/polar/overview.md

  - Platform capabilities, authentication methods, MoR concept
• Products & Pricing:

  references/polar/products.md

  - Product types, pricing models, usage-based billing
• Checkouts:

  references/polar/checkouts.md

  - Checkout flows, embedded checkout, links
• Subscriptions:

  references/polar/subscriptions.md

  - Lifecycle, upgrades, downgrades, trials
• Webhooks:

  references/polar/webhooks.md

  - Event types, signature verification, monitoring
• Benefits:

  references/polar/benefits.md

  - Automated delivery (GitHub, Discord, licenses, files)
• SDK Usage:

  references/polar/sdk.md

  - TypeScript, Python, PHP, Go, framework adapters
• Best Practices:

  references/polar/best-practices.md

  - Security, patterns, monitoring

Integration Scripts

• SePay Webhook Verification:

  scripts/sepay-webhook-verify.js

  - Verify SePay webhook authenticity
• Polar Webhook Verification:

  scripts/polar-webhook-verify.js

  - Verify Polar webhook signatures
• Checkout Helper:

  scripts/checkout-helper.js

  - Generate checkout sessions for both platforms

Implementation Workflow

SePay Implementation

1. Load

   references/sepay/overview.md

   for auth setup
2. Load

   references/sepay/api.md

   or

   references/sepay/sdk.md

   for integration
3. Load

   references/sepay/webhooks.md

   for payment notifications
4. Use

   scripts/sepay-webhook-verify.js

   for webhook verification
5. Load

   references/sepay/best-practices.md

   for production readiness

Polar Implementation

1. Load

   references/polar/overview.md

   for auth and concepts
2. Load

   references/polar/products.md

   for product setup
3. Load

   references/polar/checkouts.md

   for payment flows
4. Load

   references/polar/webhooks.md

   for event handling
5. Use

   scripts/polar-webhook-verify.js

   for webhook verification
6. Load

   references/polar/benefits.md

   if automating delivery
7. Load

   references/polar/best-practices.md

   for production readiness

Key Capabilities

• Payment gateway (QR, bank transfer, cards)
• Bank account monitoring with webhooks
• Order-based virtual accounts
• VietQR generation API
• 44+ Vietnamese banks supported
• Rate limit: 2 calls/second

• Merchant of Record (global tax compliance)
• Subscription lifecycle management
• Usage-based billing (events, meters)
• Automated benefits (GitHub, Discord, licenses)
• Customer portal (self-service)
• Multi-language SDKs
• Rate limit: 300 req/min

Instructions

1. Identify platform based on requirements (Vietnamese vs global, payment types)
2. Load relevant references progressively as needed
3. Implement authentication using platform-specific methods
4. Set up products/pricing according to business model
5. Implement checkout flow (hosted, embedded, or API-driven)
6. Configure webhooks with proper verification
7. Handle payment events (success, failure, refund)
8. Test thoroughly in sandbox before production
9. Monitor and optimize using platform analytics