Payment Integration

Implement payment processing with SePay (Vietnamese payments) and Polar (global SaaS monetization).

When to Use

Use when implementing:

• 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

Choose SePay for:

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

Choose Polar for:

• 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

SePay:

• 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

Polar:

• 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

When implementing payment integration:

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

Load only the references needed for current implementation step to maintain context efficiency.