nginx.org C Module Development Best Practices

Comprehensive development guide for nginx C modules, derived from the official nginx development documentation and community expertise. Contains 49 rules across 8 categories, prioritized by impact to guide correct module implementation and prevent common crashes, memory leaks, and undefined behavior.

When to Apply

Reference these guidelines when:

• Writing new nginx C modules (handlers, filters, upstream, load-balancers)
• Implementing configuration directives and merge logic
• Managing memory with nginx pools and shared memory zones
• Handling the HTTP request lifecycle (body reading, subrequests, finalization)
• Working with nginx's event loop, timers, and thread pools

Rule Categories by Priority