API-Fence

API-Fence is a high-performance Envoy HTTP filter written in Rust that validates HTTP requests and responses against OpenAPI 3.x specifications.

Key Features

• OpenAPI 3.x Validation - Validate request and response bodies against JSON Schema
• ModSecurity WAF - Integrated WAF with bundled OWASP CoreRuleSet v4.0.0
• Mock Response Generation - Generate mock responses from OpenAPI examples for testing
• High Performance - Written in Rust with async validation thread pool
• Security Hardening - Configurable limits for path length, body size, JSON depth
• Schema Caching - LRU cache for compiled JSON Schema validators
• Prometheus Metrics - Built-in metrics for monitoring validation and cache performance
• Envoy Dynamic Metadata - Validation results accessible in access logs and other filters

Quick Start

{
  "api_name": "my_api",
  "openapi_spec_path": "/etc/envoy/openapi.yaml",
  "validation": {
    "validate_request": true,
    "fail_on_request_error": true
  }
}

See Getting Started for installation and basic setup.