Skip to content

Introduction

Introduction

fcgx is a minimal, robust, and modern FastCGI client library for Go. It is designed for integrating with PHP-FPM and other FastCGI servers, providing idiomatic Go code, high testability, and correct protocol handling.

Why fcgx?

When working with PHP-FPM from Go applications, you need a reliable way to communicate via the FastCGI protocol. fcgx provides:

  • Context Support: Full support for Go contexts, deadlines, and timeouts
  • Thread Safety: All methods are safe for concurrent use
  • Structured Errors: Sentinel errors for robust error handling with errors.Is
  • Memory Efficiency: Buffer pooling to minimize allocations
  • Standards Compliance: Correct FastCGI protocol implementation

Use Cases

fcgx is ideal for:

  • PHP-FPM Monitoring: Query PHP-FPM status pages and pool metrics
  • Health Checks: Implement health check endpoints for PHP applications
  • Kubernetes Probes: Build readiness and liveness probes for PHP workloads
  • Metrics Collection: Gather performance data from PHP-FPM pools
  • API Gateways: Route requests to PHP backends from Go services

Features Overview

Feature Description
Context Support Deadlines, timeouts, and cancellation
HTTP Helpers Get() and Post() convenience methods
Response Parsing Automatic HTTP response parsing
JSON Support Built-in JSON unmarshaling with ReadJSON()
Configuration Customizable timeouts and buffer sizes
Error Handling Structured sentinel errors

Next Steps

Next → Installation