Blog
All articles. All pillars. All authors.
The Middleware Stack: Auth, Rate Limiting, and Idempotency
How 0fee.dev handles API key auth, Redis-based rate limiting, and idempotency keys to prevent duplicate payments. By Juste A. Gnimavo and Claude.
Webhook Delivery and Retry System
How 0fee.dev delivers webhooks with HMAC-SHA256 signatures, exponential backoff retries, and auto-disable after failures. By Juste A. Gnimavo and Claude.
Encryption and Credential Management for Payment Providers
How 0fee.dev encrypts payment provider credentials with Fernet/AES, manages per-app secrets, and what the security audit found. By Juste A. Gnimavo and Claude.
The Unified Payment Format: PAYIN_ORANGE_CI
How 0fee.dev unified 117 payment methods into the PAYIN_OPERATOR_COUNTRY format, simplifying API calls to a single field. By Juste A. Gnimavo and Claude.
Stripe Integration: Global Card Payments
How 0fee.dev integrates Stripe Checkout Sessions for global card payments, handling zero-decimal currencies and middleman callbacks.
PayPal Integration: Orders API and Redirect Flow
How 0fee.dev integrates PayPal Orders API v2 for global wallet payments with redirect flow, capture on return, and webhook handling.
Hub2: Covering Francophone Africa
How 0fee.dev integrates Hub2 for mobile money payments across 8 Francophone African countries with Orange, MTN, Wave, and Moov.
PawaPay: Pan-African Mobile Money for 21+ Countries
How 0fee.dev integrates PawaPay's hosted payment page for mobile money across 21+ African countries with correspondent codes.
Building a Payment Platform From Abidjan, Ivory Coast
How we built 0fee.dev from Abidjan with one CEO and one AI CTO in 86 sessions over 80 days. Zero human engineers. By Juste A. Gnimavo.
42 Files, 7,900 Lines, 45 Minutes: The First Session
How we built the entire 0fee.dev backend in 45 minutes: 42 files, 7,900 lines, 5 payment providers, 30+ API endpoints. By Juste A. Gnimavo and Claude.
The Middleman Callback Pattern: Verifying Every Payment
How 0fee.dev's middleman callback pattern verifies every payment by intercepting provider redirects before reaching the developer.
Building a SolidJS Dashboard From Scratch
How we built 0fee.dev's SolidJS dashboard with stores, component architecture, real API integration, and 3-layout routing system.