Implement Webhook System for External Integrations

[akargi]

Overview

Build a robust webhook system that allows external applications to subscribe to events from the InterChangableTrade platform, enabling real-time integrations with third-party services and custom applications.

Description

External partners and integrations need real-time notifications of platform events (trades, settlements, balance changes) to build automated workflows and synchronized systems.

Requirements

• Webhook endpoint registration and management
• Event subscriptions with flexible filtering
• Webhook payload signing and verification for security
• Retry logic with exponential backoff for failed deliveries
• Webhook delivery tracking and status monitoring
• Admin dashboard for webhook management
• Test webhook delivery functionality
• Rate limiting per webhook endpoint
• Webhook event history and audit trail
• Support for custom headers and authentication tokens

Acceptance Criteria

• Webhook entity and subscription models created
• POST /api/webhooks registers new webhook with event filtering
• Webhook payloads signed using HMAC-SHA256
• GET /api/webhooks returns user's registered webhooks
• Webhooks deliver events within 5 seconds of triggering event
• Failed webhook deliveries retry up to 5 times with exponential backoff
• GET /api/webhooks/:id/deliveries shows delivery history
• Test webhook functionality available for debugging
• Unit tests for webhook signing and verification (>85% coverage)
• E2E tests validate webhook delivery across events
• Performance: webhook queuing adds <50ms latency
• Swagger docs include webhook payload examples for all events